Department no. 103 Hon. Lance A. Ito, Judge
APPEARANCES: (Appearances as heretofore noted.)
(Janet M. Moxham, CSR no. 4855, official reporter.)
(Christine M. Olson, CSR no. 2378, official reporter.)
(The following proceedings were held in open Court, out of the presence of the jury:)
THE COURT: All right. Good morning, counsel. Back on the record in the Simpson matter.
MR. SHAPIRO: Good morning, your Honor.
THE COURT: Mr. Simpson is again present before the Court with his counsel, Mr. Shapiro, Mr. Blasier, Mr. Scheck and Mr. Neufeld. Also present Mr. Uelmen. The People are represented by Mr. Clarke and Mr. Darden. The jury is not present. The record should reflect that this morning at eight o'clock the Court met with counsel informally for an hour this morning to review and discuss the various crime scene and autopsy photographs that the Prosecution wishes to offer into evidence. And that the Defense, at the request of the Court, will be filing a written response to the Prosecution's letter of April the 14th. That is to be filed by the close of business Friday, May the 12th, and that we will have the formal hearing as to each one of the photos the afternoon, May the 24th, at 4:00 P.M. All right. Mr. Neufeld, you indicated you had a matter you needed to take up before we resume with Dr. Cotton.
MR. NEUFELD: Yes, your Honor. Actually there are a few matters. As you may recall, we met twice already on the boards that the People intend to use today.
THE COURT: Yes.
MR. NEUFELD: And you were going to rule, one, on the objection to the use of the word "source." We believe that the proper term for that column should be "failed to exclude" and not "excluded by" because these are all, as even Dr. Cotton will testify or will testify, these are tests of exclusion and that is the standard terminology in the scientific literature, in the scientific community, so that is one of the issues that has to be resolved before the boards come out. I think you have already resolved, and I may be mistaken or the People consent to remove the "trail" word so that is no longer an issue. Then we have the issue of mixed stains and you had asked the People to first produce yesterday numbers on what the aggregate frequencies would be for the mixed stains. Umm, I'm told by Mr. Clarke that there is still--they don't have those numbers yet. But that obviously has to be resolved before the boards come out as well. Finally, your Honor, and perhaps most importantly, we talked about both in the interest of saving time and preserving a record that we would have standing objections before the various questions are posed to Dr. Cotton on issues which we had specifically objected to in Defendant's notice of objections to the testimony concerning DNA evidence and memorandum in support of this which was filed with the Court I believe on March 20, 1995. And the Court issued a written decision with respect to that motion. What we would like to do, obviously, is at this point--or get some guidance from the Court--is again incorporate this notice of objections by reference, and insofar as the witness, the witness' testimony, touches upon any of the issues which we have specifically raised in our notice of objections, that the Court will deem it that we object to that testimony and to the witness' answer, so we don't have to constantly interrupt the proceedings all along.
THE COURT: All right. Mr. Clarke, let's address the trail issue first. I take it you have consented to revise the board to "walkway and driveway"?
MR. CLARKE: Yes, that's fine, your Honor, and in fact those patches have been prepared or are being prepared.
THE COURT: All right. As to the concern about the nomenclature source, on the source versus not excluded, have you reevaluated your position on that?
MR. CLARKE: I think, as I mentioned to the Court last week, that it is our belief that, frankly, the term "possible source" is synonymous and neutral and there is no need to change it, but we do have patches if the Court so directs, however.
THE COURT: What patch do you have prepared?
MR. CLARKE: One that says "not excluded" for that particular column.
THE COURT: I will direct the use of the "not excluded" label. All right. As to the mixed stains issue?
MR. CLARKE: I think with regard to that issue we are going to have to require some more of the Court's time. This has taken some substantial mathematical calculations based on the samples that are involved, and I think an important background is as follows: With respect to this witness' testimony, there are only two particular samples that are involved. I don't know if the Court wants me to get into detail, but it is going to be our request that we actually convene a hearing with this Court about the issues that are involved in this, and they include, for instance, our position that this issue use has been totally waived by the waiver of a hearing. So I think we need some of the Court's time. I'm not going to get that far this morning, so however the Court would like to proceed with it, I think we need a more formalized hearing process.
THE COURT: All right. Refresh my recollection as to which mixed stain comes up in Dr. Cotton's testimony.
MR. CLARKE: There are two. One is item no. 78 from the bottom of Mr. Goldman's shoe that also has RFLP results. That one makes that one slightly unique in this series of results in this case as far mixtures. And the second item is the stain from the steering wheel of the Bronco that as I believe I mentioned to the Court last Friday, frankly, that stain is a little bit different than the others as well because while consistent with Mr. Simpson, there is obviously another contributor that is not directly related or may not be directly related to this case on the steering wheel, so that one is slightly different from the other mixtures as well. In this mixture issue, while I agree it needs to be resolved in some fashion before frequencies are discussed by Dr. Cotton, is frankly more relevant in the ensuing witness' testimony as well.
THE COURT: All right. Then I would suggest we take that up at one o'clock. Let's proceed with Dr. Cotton's testimony and we will get to the mixed stain issue at 1:00.
MR. CLARKE: Very good.
MR. SCHECK: One other brief--
THE COURT: I'm sorry. Let me ask Mr. Clarke one other question. Do you have any objection to the Court deeming the--allowing a standing objection as per the previous memorandum of points and authorities that was filed in late March?
MR. CLARKE: No, not with the--as long as it is with the understanding that we believe those objections have been waived previously as well, but as far as eliminating the need to object at every step, certainly that I think is an appropriate way of proceeding.
THE COURT: All right. Then I will deem these objections have been made for the course of the presentation of this witness. Mr. Scheck.
MR. NEUFELD: Obviously to the next--to the other DNA witnesses as well so we don't have to bring it up again.
THE COURT: Noted.
MR. SCHECK: Your Honor, after a lot of hard work, we have come up with a proposed instruction, preliminary instruction on DNA statistics, that is four short paragraphs, very short. I think balanced and a real candidate for Caljic. Isn't that what they call it here?
THE COURT: Yes.
MR. SCHECK: And I think it is one of the most important rulings you will make in the whole case and it is our best effort, very short.
THE COURT: All right. Do you have copies for opposing counsel?
MR. SCHECK: I have given Mr. Clarke a copy and maybe this is something that you would take up at one o'clock as well.
THE COURT: All right.
MR. SCHECK: I think it is-- (Brief pause.)
THE COURT: All right. Deputy Magnera, let's have the jury, please.
MR. CLARKE: I'm sorry, your Honor.
THE COURT: Mr. Clarke.
MR. CLARKE: Just one question. With respect to this witness' testimony, I understand there is available a wireless microphone, and when Dr. Cotton is, for instance, down in front of the jury, sometimes her voice is not being picked up by a microphone and I think it may aid her in being understood by the jury. With the Court's permission, we would like to use that.
THE COURT: If she is down off the witness stand then she is standing right before the jury box. Do you think it is really necessary?
MR. CLARKE: I think at times with these boards she is occasionally facing away, I think it will help, but I will leave that to the Court's discretion, obviously.
THE COURT: Where is Dr. Cotton? Dr. Cotton, are you familiar with the perils of using wireless microphones?
DR. COTTON: No, I don't think so.
THE COURT: Have you discussed this with her, Mr. Clarke?
MR. CLARKE: Only very briefly.
THE COURT: What is your feeling on that, Dr. Cotton?
DR. COTTON: I don't know what the perils are.
THE COURT: No. My point--how is your voice holding up?
DR. COTTON: Oh, it is fine. You know, we could wait until this afternoon and see if I'm having any problems.
THE COURT: The Court reporter seems to be voicing an opinion.
REPORTER OLSON: When her back is to me and she is facing the jury I do have difficulty understanding her.
THE COURT: Dr. Cotton, realizing there are no off-the-record comments while you are using the microphone--
DR. COTTON: I see.
THE COURT: All right. Let's use the microphone.
MS. PIETZ: Your Honor, I will need about five or ten minutes to set it up.
THE COURT: All right. Then we will proceed. Let's have the jury, please.
(Brief pause.)
(The following proceedings were held in open Court, in the presence of the jury:)
THE COURT: Thank you, ladies and gentlemen. Please be seated. And Dr. Cotton, would you resume the witness stand, please.
Robin Cotton, the witness on the stand at the time of the evening recess, resumed the stand and testified further as follows:
THE COURT: All right. Good morning again, Dr. Cotton?
DR. COTTON: Good morning.
THE COURT: You are reminded, ma'am, you are still under oath. And Mr. Clarke, you may continue with your direct examination.
MR. CLARKE: Thank you, your Honor. Good morning, ladies and gentlemen.
THE JURY: Good morning.
DIRECT EXAMINATION (RESUMED) BY MR. CLARKE
MR. CLARKE: Dr. Cotton, as far as these methods of DNA typing, and you have talked in broad terms about PCR and in more detail about RFLP, are these techniques simply a better way to type stains than for instance, ABO typing or conventional serology?
DR. COTTON: Yes, they generally will offer more information than conventional serology will offer.
MR. CLARKE: Again we spoke about RFLP or you spoke about RFLP typing yesterday. The second technology that you mentioned briefly yesterday I believe you referred to as PCR; is that right?
DR. COTTON: That's right.
MR. CLARKE: What year was that process discovered?
DR. COTTON: I believe that the first paper on PCR was published in 1985.
MR. CLARKE: As far as its use in forensics, is it newer or older than the RFLP typing process?
DR. COTTON: It is actually about--it came along at about the same time, although it was not being used quite as widely early on as the RFLP process.
MR. CLARKE: Are you familiar with who was the first scientist to use this PCR process in forensics?
DR. COTTON: Yes, I am.
MR. CLARKE: Who was that?
DR. COTTON: That would be Dr. Ed Blake.
MR. CLARKE: Do you know approximately when that forensic use of that technique occurred?
DR. COTTON: I only know that it was early, maybe 1986 or so.
MR. CLARKE: As far as this PCR process--and many of us, not all of us have heard of the movie Jurassic Park--what does PCR have to do with that?
MR. NEUFELD: Objection, your Honor. That is irrelevant.
THE COURT: Sustained.
MR. CLARKE: PCR does what? Can you give us a very brief summary?
DR. COTTON: PCR is a way of saying I want to replicate a small section of DNA and it allows you to replicate a small section of DNA in a way that if you have a very small amount of starting material, you can go through sufficient number of replications so that by the end of the process you will have enough of this small section to then do some analysis on.
MR. CLARKE: What role does it play, for instance, in old samples? And let's first of all ask can this process be used on samples of DNA that are perhaps years or decades or centuries old?
DR. COTTON: It can and it is being used on those types of samples.
MR. CLARKE: What types of samples is that?
DR. COTTON: There are samples from, I don't know what the proper term would be, but very ancient, for example, bone samples that have had very short sections, copied using PCR to look at how genes have changed over time. That is, if you can have a sample from a human being who is several thousand years old and look at a particular sequence of the DNA, you might say, well, how does that sequence compare to the same sequence in--in modern human beings?
MR. CLARKE: Has PCR been used on ancient animals?
DR. COTTON: I don't really know. It may have been but I don't really know.
MR. CLARKE: As far as this PCR process, is it like RFLP in the sense that it is a testing method or is it something a little bit different?
DR. COTTON: PCR is simply the process that allows you to make a lot of copies of a particular section of DNA and then the rest of the analysis may have many different forms. That is, what you do now with your section of DNA that you've replicated many times may not be the same for every purpose or every question.
MR. CLARKE: Would it be correct then that PCR would be more like one step in a typing process when DNA is being typed?
DR. COTTON: Yes.
MR. CLARKE: What about your own knowledge of PCR? How did that come about?
DR. COTTON: Umm, I had been to several meetings where PCR was discussed. I had done some reading where PCR was discussed. My own hands-on experience came from visiting two different laboratories where they were actively doing PCR and learning from the staff in those laboratories how to do PCR, and these--both of these visits to other laboratories, one was two weeks and one was a week. I had an opportunity then to learn from the staff there to do it myself and then back--going back to cellmark to help the rest of the cellmark staff who also had--some of whom had also been out to get training, which was different than mine, to set up the PCR that we do there.
MR. CLARKE: Who were the individuals that you--I'm sorry--whose labs you visited to learn PCR?
DR. COTTON: I went to a laboratory at Houston that was Dr. Tom Caskey and I went to Dr. Alex Jeffries' lab in the UK.
MR. CLARKE: The same Dr. Jeffries that you described yesterday?
DR. COTTON: Yes.
MR. CLARKE: How about your own personal hands-on experience with PCR? Could you describe that, please.
DR. COTTON: Well, I had those three weeks and then I had some experience hands-on time doing the PCR reaction while I was--while we were in the process of doing validation studies to set up PCR in our laboratory, and a number of other people did, too. I don't--I am not doing the PCR tests now. The PCR tests are done by the regular staff.
MR. CLARKE: As far as this copying process, is there a term used to describe what you actually do in taking small segments of DNA and copying them over and over?
DR. COTTON: Yes. The term is amplification. So people will talk about I have amplified a certain section of DNA.
MR. CLARKE: This process--and I believe you said that this process of copying over and over is directed at short segments of DNA?
DR. COTTON: The segments that are used for forensic analysis are relatively short and I'm talking about perhaps a hundred, 200, up to 400 base pairs in length. That is a pretty--in DNA terms that is a pretty small piece.
MR. CLARKE: So you are not talking about copying over and over this entire segment of DNA that you described as containing what was it, six billion bases or so?
DR. COTTON: No. You are not copying the whole thing; you are just copying a particular section.
MR. CLARKE: With regard to this copying possess, would it help to use a chart or a pad so that you could draw what this amplification or copying process involves?
DR. COTTON: Sure.
MR. CLARKE: Your Honor, then with the Court's permission Mr. Fairtlough will I believe set up the drawing pad for the witness.
THE COURT: We will reassemble our drawing pad.
MR. CLARKE: Reassemble.
THE COURT: Yes.
(Brief pause.)
THE COURT: And Mr. Clarke, I noticed yesterday that you were using the dry erase type marker. Does that have a longevity to it, permanence to it?
MR. CLARKE: I hope it is not disappearing ink.
THE COURT: You will notice that is what you are using there is dry erase.
(Brief pause.)
MR. CLARKE: All right. Your Honor, may this diagram be marked as People's next in order, which I believe is 247?
THE COURT: 247.
(Peo's 247 for id = diagram)
MR. CLARKE: All right. Dr. Cotton, if you could step down from the witness stand, and what would be an appropriate label for this chart to aid you in describing this copying process or amplification?
DR. COTTON: We will just call it "amplification."
MR. CLARKE: Very good. If you could just write that at the top.
DR. COTTON: (Witness complies.)
MR. CLARKE: All right. Now, if you would go ahead and if you could describe for the jury, please, what is this copying process?
DR. COTTON: Okay. Keep in mind now that you are starting--you have a sample and you have extracted the DNA, so those steps are the same as or similar to the RFLP process, and so let's just say for simplicity purposes that we have a single chromosome's worth of DNA that I'm going to use as a reference point here. So we are going to put in the tube our starting DNA and we are going to put in the tube a supply of the four DNA components; A's, G's, T's and C's and we will also put in the tube an enzyme, this is a protein, and it is called a polymerase, and this polymerase is basically going to assemble the A's, T's, G's and C's, and we are going to put one more thing in, which is referred to as a primer, and that is a very small piece of single-stranded DNA, usually about 20 bases or so. It can be longer or shorter, but that is just an example. So that we now have the components to make more DNA. This is what we are going to use to make more. We need our starting material, we need the building blocks, we need something to put the building blocks together, which is the polymerase, and the primer serves as an anchor for that polymerase to hold on to.
MR. CLARKE: Let me stop you for just a moment, Dr. Cotton. With regard to this term "polymerase," is that the first word of PCR, the process itself?
DR. COTTON: Yes.
MR. CLARKE: What does it stand for again?
DR. COTTON: Polymerase is a protein which can assemble more DNA in this case.
MR. CLARKE: And what does PCR actually stand for, what are the words?
DR. COTTON: PCR stands for the polymerase chain reaction and basically you are going through a cycle of steps which is why it is referred to as a chain reaction. You are repeating a cycle of steps over and over and over again. And what we will do here is just show you what one or two cycles looks like.
MR. CLARKE: All right. Go ahead.
DR. COTTON: So the first thing we will do is heat this DNA back up to about 95 degrees, enough so the strands will separate.
MR. CLARKE: Again, that is Centigrade, not Fahrenheit?
DR. COTTON: Yes. And at that will point we will allow the short primers or anchor points to bind and this is--these primers are designed so that the sequence of DNA that they have to hook up to is known and so you have a single-stranded piece in the primer, binding to this now single-stranded starting material, and all the A's and T's and G's and C's are pairing up. And then the polymerase will come along and directed by the bases on your starting material will reassemble a second strand.
MR. SHAPIRO: Your Honor, there is a juror that wants to get your attention.
JUROR NO. 2179: I can't see.
THE COURT: All right. Mr. Clarke, we have a vision problem.
MR. CLARKE: Yes.
(Brief pause.)
MR. CLARKE: Your Honor, would it be possible to put the drawing pad here where the podium is?
THE COURT: Let's put it there.
(Brief pause.)
THE COURT: Why don't you turn it as directly perpendicular as you can.
(Brief pause.)
THE COURT: Thank you.
MR. CLARKE: I'm not sure we have solved all the vision, though.
THE COURT: All right. Juror no. 1, can you see that?
JUROR NO. 230: I can see. That's fine.
THE COURT: Thank you, counsel. Proceed.
(Discussion held off the record between the Deputy District Attorneys.)
MR. CLARKE: Dr. Cotton, if you could, could you briefly describe again what you've already described and perhaps you can point to the various portions of the chart so that each of the jurors may see it.
DR. COTTON: Okay. We have double-stranded DNA starting material. We are going to heat the two strands, we'll just put a little "x" here on our starting material strands, drop the temperature down, allowing the primer to bind, the two primers to bind, and then allowing the polymerase to make a copy of this starting strand. So the polymerase is basically going along and says I have a t on my starting strand, I will put an a in. I have a C on my starting strand, I will put a g in. I also have a g on my starting strand, I have to put a C in, and so on. So now where we originally had a single strand to start out with, we now have two. Now, I'm--
MR. CLARKE: Go ahead.
DR. COTTON: --I'm sort of going to run out of a length of paper, but the idea is that you then start the process all over again, so you go--I have to stand on this side--so you go, start the cycle again, heat it up. These two double strands will come apart, these two double strands will come apart and now again you let--drop the temperature down and let the primers bind. And I have just made these shorter because there is not enough room. They wouldn't really be shorter, they would be the same length. And then allow the polymerase finish off making the copy for each one of those and so now we have four completed strands where we only started with one. So as you can see, each time you go through the cycle, you are going to double the number of strands that you started out with. If we start out with one, then we would go to two and then we go to four and the next cycle you would go to eight and so on.
MR. CLARKE: All right. Let me--perhaps you can stand on the other side so that I can ask you a question, a few questions about this process. You have used the term "primer." Does it act as something like a primer in priming a pump, for instance?
DR. COTTON: Well, it is not a bad analogy; it is not great. What it is, is the--the characteristics of the enzyme are such that it needs an end to start from. If you just separated the strands, it wouldn't have a place, it doesn't have an anchor point, so the primer is serving as an anchor point for the enzyme to then connect the next base to. It needs something in the way of the start of a second strand to actually connect, so the primers are in there both to say this is the section we want to copy. That is really what the primer does, is it identifies the section that you want to copy and then it starts as an anchor point for that enzyme to sit down and then move through and copy that piece of DNA.
MR. CLARKE: How do you know where the primer actually attaches to this segment of DNA?
DR. COTTON: You have designed your system, that is, you have to know up front the sequence of bases of the piece of DNA that you want to copy. There has to have been enough research done and development done so that--at least in the forensic setting here, you must know ahead of time the sequence of bases that exist in the piece that you want to copy. That has to be done ahead of time. Then you can manufacture in the lab the primers that have the sequence at the beginning and the end and then you are set to go.
(Discussion held off the record between the Deputy District Attorneys.)
MR. CLARKE: As far as these known sequences of where it starts, for instance, and you mentioned you have to know the sequence, have scientists looked at these areas to determine their sequences?
DR. COTTON: Yes. The development work for the genetic locations that are used for forensic testing with the PCR methodology, these regions have all been sequenced and a lot of other work, besides the sequencing, has been done to study these regions before applying that information to actually designing a forensic test.
MR. CLARKE: This copying process, first of all, do our bodies do that by themselves?
DR. COTTON: Not with this particular polymerase because this polymerase comes--is able to work at a very high temperature, but all our bodies have a similar enzyme so that when a cell replicates and divides to form two new cells, in the process of doing that you are replicating the DNA and the enzymes that perform that replication are also called polymerases.
MR. CLARKE: Would it be correct to say then that this PCR process simply does outside the body what the body does on its own?
DR. COTTON: Basically that is right.
MR. CLARKE: And it is as simple as that?
DR. COTTON: (No audible response.)
MR. CLARKE: In terms of this division in copying and so forth?
DR. COTTON: Yes.
MR. CLARKE: All right. Now, your Honor, if we could, I would like to put that drawing pad back where we had it yesterday and then continue on with some additional prepared charts.
THE COURT: All right.
MR. CLARKE: Perhaps you could have a seat again on the witness stand, Dr. Cotton, but probably not for too long.
DR. COTTON: (Witness complies.)
(Discussion held off the record between the Deputy District Attorneys.)
MR. CLARKE: Now, as far as this use of PCR, and I will step over here, Dr. Cotton, as far as this use of PCR in forensics, to your knowledge do we have some charts, prepared charts, that illustrate how you actually use this technique to type samples in forensic case work?
DR. COTTON: Yes. I have seen the chart that you are referring to.
MR. CLARKE: All right. Your Honor, at this time I would ask to be marked as People's next which I believe is--
THE COURT: 248.
MR. CLARKE: 248.
(Peo's 248 for id = chart)
(Discussion held off the record between Deputy District Attorney and Defense counsel.)
MR. CLARKE: Your Honor, for the record, this diagram can be labeled or can be described as "PCR analysis," and then showing at the top two large blocks, "step 1, extraction" and "step 2, amplification" and then a smaller block labeled "step 3, "detection."
THE COURT: Yes.
(Discussion held off the record between the Deputy District Attorneys.)
MR. CLARKE: All right. Dr. Cotton, with regard to this chart that has been placed on the board, have you had an opportunity to look at this before this morning?
DR. COTTON: Yes, I have.
MR. CLARKE: And with regard to this chart, does it illustrate various steps in the PCR-based typing process in forensics?
DR. COTTON: Yes, it does.
MR. CLARKE: Now, in particular--well, are there a number of steps that occur in this typing process?
DR. COTTON: Sure.
MR. CLARKE: In general terms are there fewer steps than in the RFLP typing process that you described yesterday?
DR. COTTON: Oh, there might be fewer. It sort of depends on how you count them.
MR. CLARKE: Okay. This board itself, and it is labeled at the stop "step 1, extraction." Can you describe what that refers to, and if there is a pointer there that would help you, please feel free to use it.
DR. COTTON: The top rectangle is simply illustrating that you have some kind of a stain and from that you do a DNA extraction and the DNA is going to end up basically in your test-tube and these tubes are actually very small. And then to that tube you will add, in addition to adding your DNA, you will add what is diagrammed up here as the PCR mix and the PCR mix is the DNA components, the A's, T's, G's and C's, the polymerase and the primers and some other salts or buffers, so all of those things go together in a single tube.
MR. CLARKE: All right. What happens at that point?
DR. COTTON: At that point you take that tube and put it in what's called a thermal cycler, it sort of looks like a cash register actually or a small one, but it has a metal block which is illustrated right here, (Indicating), and a computerized programmable method for controlling the temperature in that metal block, so the tube sits down very tightly. The holes in the block are simply the same shape as the tube so that when you put the tube down there, there is close contact between the tube and the walls of the metal block, and the temperature in the tube is then controlled by heating or cooling the metal block and you do this in a cyclical manner. And the cycle goes as we talked about a little while ago. You are heating the block up to 95, so the contents of the tube will be at 95, so you can denature the DNA, separate the strand, and the temperature is then dropped down. And I am not going to be able to remember what the exact temperatures are in the cycle, but the temperature is dropped down somewhere usually around 60 or 64 or 65 degrees, it could even be lower than that--anyway I don't remember right now--to allow the primers to bind and then the temperature is raised up to around seventy degrees to allow the enzyme to complete copying of the strand and then the cycle starts all over again. So you tell the machine in your programming what specific temperatures you want it to cycle through and how many cycles you want it to go through.
MR. CLARKE: In other words, this machine, you can program it or tell it basically how many of these cycles to go through, at what temperatures and so forth?
DR. COTTON: That's right, and how long each cycle is to be, like you are going to have it at 95 degrees for one minute and then you will drop it down to 55 degrees and stay there for thirty seconds and then you will raise it up to 70 degrees and you will stay there for, you know, fifty seconds or something like that.
MR. CLARKE: This heating and cooling process that you described, was PCR process used before there were machines that did this in a fairly automated fashion?
DR. COTTON: It was and my understanding was that when PCR was developed that basically the people were doing this by hand, that is, holding the tube in a water bath at a hundred degrees and then taking it out and putting it in another water bath at another temperature. So it would have been very tedious to do that. You would have a lot of researchers standing around taking up a lot of their time holding their tubes in water baths, so anyway, the computer age came and this machine was developed to essentially take care of that for you. So you put your tubes in, you set the machine up and turn it on and it goes through as many cycles as you have programmed it to do and then it holds your tube at a cool temperature until you come and retrieve it.
MR. CLARKE: Just briefly, there is a step 3 listed, that is called "detection." Is it your understanding that we will return to that in some detail in just a few moments?
DR. COTTON: Yes.
MR. CLARKE: All right. With regard to this amplification process, and in particular how these strands are copied, would it aid you to use a prepared diagram showing two different double helixes or ladders?
DR. COTTON: That only really relates to the kind of detection that we are doing.
MR. CLARKE: Very good.
DR. COTTON: So we could leave that for--
MR. CLARKE: As far as the detection itself?
DR. COTTON: Yes.
MR. CLARKE: Okay. Then if I could, I would like to return to the drawing pad. And Dr. Cotton, could you use the diagram and let's--let's add a new page if we could that I believe would be People's--
THE COURT: 249.
MR. CLARKE: 249.
(Peo's 249 for id = diagram)
MR. CLARKE: And with regard to this, if you could just illustrate and I would like you to actually write down a series of--just for illustrative purposes or examples--bases and how in this copying process how the primer would then act to add these bases that are floating around in this tube mixture. Do you understand what I'm asking?
DR. COTTON: I think so.
MR. CLARKE: Okay.
DR. COTTON: You want me to take a double strand, take it apart and show how the second strand is reconstructed?
MR. CLARKE: Correct. Just one cycle is fine.
DR. COTTON: Right.
MR. CLARKE: What would be an appropriate title to illustrate that point?
DR. COTTON: "more amplification."
MR. CLARKE: Okay.
THE COURT: I'm sorry, I couldn't hear the answer.
DR. COTTON: "more amplification." It is going to take me a minute to set this up.
MR. CLARKE: Very good.
(Brief pause.)
DR. COTTON: Okay. So I've made a very short sequence and I see there is a flaw in my thinking here, but we will sort of try to work past that. Double-stranded A's and T's, G's and C's nicely paired up and heated and create the two single strands. We are just unzipping the zipper. And now we want our primer to bind, so here is the flaw in my thinking. I'm going to have to make for a very short primer, because I didn't draw a very long sequence, so let's say we have put in a primer here, (Indicating), to have two T's and we put in a primer to fit the other side, which is going to be a t and a G. And you can see that this primer won't attach to this side and this primer won't attach to this side and the primers won't attach to each other, so you have to take these things into consideration and then you simply have your enzymes come along and the enzyme will come along and create this new strand. It will use this primer as its anchor point and now add--and remember we have got, you know, just individual A's, T's, G's and C's floating around here available to be put into the new DNA strands, so the primer will come along and correctly make a brand new strand on both sides.
MR. CLARKE: And what you--
DR. COTTON: I said primer but I meant polymerase. The polymerase will come along, hook onto this primer and correctly make--finish off here the new strand, (Indicating).
MR. CLARKE: So what you have illustrated is basically how this process works with the use of the primers and how from one strand you create two strands?
DR. COTTON: Yes.
MR. CLARKE: And then that process just continues through the cycles a number of times over and over that you described a few moments ago?
DR. COTTON: That's right.
MR. CLARKE: All right. Then Dr. Cotton, if you would, and what I'm going to ask you is with--
(Discussion held off the record between the Deputy District Attorneys.)
MR. CLARKE: Excuse me, your Honor. May I have a moment?
(Discussion held off the record between the Deputy District Attorneys.)
MR. CLARKE: Just a couple more questions if I could, Dr. Cotton. With regard to this primer, it latches onto the other side of the DNA strand; is that right?
DR. COTTON: It will bind--there is no other side. This is a single strand now and this is a single strand at the point that you've heated it, so the primer is the first starting point to creating another side.
MR. CLARKE: And it is from the primer on up or down the ladder, as the case may be, that it then starts this process of adding these bases one at a time?
DR. COTTON: That's right.
MR. CLARKE: All right. Very good. With regard to--and now just referring very previously to the large chart, which I believe is People's exhibit 248, as far as this--and you have described the second step on this chart, "amplification"; is that right?
DR. COTTON: That's right.
MR. CLARKE: With regard to the third step, is that the final basic step in this process of PCR typing?
DR. COTTON: That's right. You are going to--now you have made lots of copies of your DNA and you want to look at it for purposes of forensic use. You will be copying sections of DNA that have some difference from person-to-person and now you want to figure out, well, what does that difference look at for the sample I just copied.
MR. CLARKE: In other words, you actually determine the types in a particular sample so you can determine what persons can be excluded or included as possible donors?
DR. COTTON: That's right.
MR. CLARKE: With regard to this detection possess, is it the same or different from what you are looking for using the RFLP method?
DR. COTTON: Depending on the genetic location that you have amplified, there is--one of the detection methods is similar to the RFLP. That is, you are simply looking at how long a piece of DNA is you amplified. You know you started at one end, but there is some variation in the length, and you may need to explain that a little bit more. But the other--the other type of test that is available does not have anything to do with length really, but has to do with a sequence difference, so that at a particular genetic location I might have one sequence, Mr. Clarke might have another, Mr. Goldman, might have another, and so could you look at the sequence differences.
MR. CLARKE: Do we have a board that will illustrate that difference as well?
DR. COTTON: Yes, we do.
MR. CLARKE: All right. Your Honor, I would ask that a prepared diagram be marked as--
THE COURT: People's 250.
MR. CLARKE: Thank you.
(Peo's 250 for id = diagram)
(Discussion held off the record between the Deputy District Attorneys.)
MR. CLARKE: Thank you. Your Honor, for the record, People's exhibit 250 could be described as labeled "DNA" with what appear to be two depictions of a ladder side-by-side, DNA ladder.
THE COURT: All right.
MR. CLARKE: Dr. Cotton, with regard to this exhibit, first of all, have you had an opportunity to see it before?
DR. COTTON: Yes.
MR. CLARKE: Would this exhibit help you describe the differences between these two methods of typing samples that you just made a brief reference to a moment ago?
DR. COTTON: Yes. It is--it is the good example for--and it--it is a point of discussion for what is a sequence difference.
MR. CLARKE: All right. Could you then use this diagram to discuss that?
DR. COTTON: Yes. What we have here is the same diagram basically that we were using yesterday do show what is a DNA molecule and here we just have two of them that are side-by-side. And if you just go, let's say, from the top to the bottom and on one you will see we have an a t pair at the top and the other there is an a t pair at the top and we come down to a GC pair and the second one also has a GC pair, but here in the middle the DNA molecule on the left has an at pair. The DNA molecule on the right as a GC pair, so-- and then if you go on down the remainder of the three base pairs here, they are alike and a GC, an at and another GC, so the only difference we have here is the fact that the third base pair down on one diagram is an at and on the other is a GC. This is a DNA sequence difference. This sequence difference can be detected because you can amplify both of these pieces of DNA and then use a detection method to allow you to--you match either these pieces or those pieces and you can figure out that you have two varieties basically in your sample. You have one molecule that has an at pair and another one that has a GC pair, and so in the PCR diagram that we were looking at a little while ago, when it got to the bottom and it says "detection," this--to amplify two pieces of DNA and then detect that they had a sequence difference is one type of detection that is used for forensic analysis.
MR. CLARKE: What is the other type of detection method that the board just named, very briefly?
DR. COTTON: The other type is looking at a length difference, which is very similar to what you are doing in RFLP. You are also looking at a length difference. But maybe we should go back to the piece of paper just very briefly.
MR. CLARKE: All right.
(Brief pause.)
MR. CLARKE: You are going to create a new diagram, Dr. Cotton?
DR. COTTON: Yes, I am.
MR. CLARKE: All right.
(Discussion held off the record between the Deputy District Attorneys.)
MR. CLARKE: Your Honor, for the record, the witness is labeling this as "PCR length difference."
THE COURT: All right. This will be 251.
(Peo's 251 for id = diagram)
DR. COTTON: What I'm going to do is go back very briefly to the same analogy or the same example that I used yesterday in terms of a repeat, so let's say we have the same C, A, t repeat and again I'm just using that because it is a very easy example, and I have two different DNA pieces here, and they--one has two repeats and the other has four. And again, if I can somehow identify the end of each of these pieces, I could look and see how long they were. For the RFLP test we defined the ends by having an enzyme come along and literally cut these sections out. You can use the PCR test to also look at the lengths and you can do that by designing your primers so they will come along and bind just outside the repeat. Now, we could go through and redraw all the amplifications, but if you think about if, we look at just one of the strands here, if our primers come along and copy this section and copy this section, (Indicating), ultimately as you go through the PCR you will end up with a piece--many pieces that are this long, (Indicating). If you do the same thing with the other piece, with your primer sitting just outside the repeats, the pieces that are eventually going to become your product or your many pieces of DNA that you have now copied will include the full length of the primers and the four repeats that I have diagrammed, whereas over here we only had two. Now, instead of having a sequence difference like the board that we just talked about, now you have PCR product, but the difference is a length difference and you can analyze that length difference by separating the DNA strands to a gel. It doesn't always have to be exactly the same kind of gel that we talked about yesterday, but the principle is exactly the same and that is the DNA strands will move through the gel and separate out according to how long they are. And that is the other commonly used method of detection for looking at your PCR product, that is, looking at some kind of genetic difference in the DNA that you have now amplified.
MR. CLARKE: As far as the sequence differences, is my sequence difference at a particular set of markers different than yours?
DR. COTTON: It may be and it may be the same. Since we haven't tested both of us, I couldn't answer that question.
MR. CLARKE: What about in the area of these length differences?
DR. COTTON: The same thing. The variation in the population for these PCR markers is not extensive, so many of us may share some things and then some of us would be different, so whether or not you and I are different, I couldn't tell.
MR. CLARKE: And that is why--
DR. COTTON: It may be, but I don't know.
MR. CLARKE: Do you look at multiple genetic markers, more than one genetic marker, to get these differences if they exist?
DR. COTTON: You look at many genetic markers as you have the ability to look at, and no matter what kind of system you are using, be it PCR or RFLP, the more markers you look at, the more genetic locations you analyze, the more information you have. That is a generalization that will always be true for forensic testing. The more markers you look at, the more information you have.
MR. CLARKE: And is that your goal as a forensic scientist, to look for as much information as possible?
DR. COTTON: That would be the goal, yes.
MR. CLARKE: Do you have one more board to illustrate this PCR typing process?
DR. COTTON: Yes, we--I think so.
MR. CLARKE: Your Honor, at this time I would ask be marked as People's next in order--
THE COURT: 251.
MR. CLARKE: --a final PCR chart.
(Discussion held off the record between the Deputy District Attorneys.)
THE COURT: I'm sorry, 252, 251 being the drawing.
(Peo's 252 for id = chart)
MR. CLARKE: Your Honor, this exhibit--252?
THE COURT: 252--
MR. CLARKE: Is also labeled "PCR analysis" but it has two small blocks at the top, "step 1, step 2" and then a large block, "step 3," for the record.
THE COURT: All right.
MR. CLARKE: Now, Dr. Cotton, with regard to this chart, People's exhibit 252, would this help you in describing how these actual differences, whether they are sequence differences or length differences, are determined by you as a forensic scientist?
DR. COTTON: Yes.
MR. CLARKE: All right. Then if you would, with this chart, then describe for the jury these differences in typing and how they work.
DR. COTTON: Okay. So step 1, we extracted the DNA. Step two, we amplified it, we used the thermal cycler, and like you saw on the previous diagram. And now based on whatever genetic location we amplified, we are going to use one of these two types of detection, and the first type that is illustrated, which is on the left, is called a dot-blot or sequence polymorphism. That is sequence polymorphism just meaning sequence difference. That is exactly what we looked at on the two DNA molecules just a few minutes ago. So the set-up is you have a nylon strip which has DNA bound to it in specific locations and that is illustrated right here, (Indicating). There is a plastic tray and the tray has like little wells in it, sort of, and the strips sit in the tray. Solution is added to those strips and your amplified DNA is added to those strips and the DNA that is spotted onto the strip will bind to whatever part of your amplified DNA that it matches up. And where the DNA binds to the strip, the strip is then processed through a series of reactions to give you a blue dot on the strip where your sample DNA bound and these blue dots are then interpreted to say you have--and this is a term we haven't used--when I talked about genetic differences, if you go back to just mother and father, if you have two differences. Those are referred to as an allele. An allele is simply a form of a gene so that, for example, the two sequence DNA differences that we showed just a few minutes ago, those could be called two alleles, or the term Mr. Clarke was using would be two types. So from the series of blue dots on the strip, you will read off the types or the alleles for that DNA sample that you just analyzed. Then you simply write those down and record those. The other method, which is diagrammed on the right--
MR. CLARKE: I'm sorry, let me stop you for a moment, Dr. Cotton.
DR. COTTON: Okay.
MR. CLARKE: Your Honor, I would ask that be marked as People's next in order what can be described as a tray containing various slots in it.
THE COURT: All right. 253, plastic tray.
(Discussion held off the record between Deputy District Attorney and Defense counsel.)
(Peo's 253 for id = plastic tray)
MR. CLARKE: Dr. Cotton, showing you what will be marked People's--I'm sorry, was that 253, your Honor?
THE COURT: 253.
MR. CLARKE: --what is that item you have in your hands?
DR. COTTON: The item is the typing tray. It is the tray that is illustrated in the top two pictures here. It is plastic. This tray has strips laid in the wells. The strips have not been processed, so there is no blue dots on them. And the tray has a clear plastic lid which I taped down so that I wouldn't lose it, and this is the typing tray that is used in the laboratory and examples of the strips that are used in the laboratory to go through this series of reactions of adding your amplified DNA and developing the blue dots on the strip and from those blue dots then you would read your types from those samples.
MR. CLARKE: Where did that tray actually come from, as well as--I'm sorry. Did you say there were strips inside the tray right now?
DR. COTTON: Yes, they are.
MR. CLARKE: Where did they both come from?
DR. COTTON: They came from my lab but they are manufactured by Perkin Elmer Cetus, I believe.
MR. CLARKE: Would that be a tray and strips then that you would have used in case work if it hadn't been brought to Court today?
DR. COTTON: Oh, sure.
MR. CLARKE: With regard to those strips--and they are currently laying in the bottom of the tray; is that right?
DR. COTTON: That's right.
MR. CLARKE: What else is put into that tray other than the strips?
DR. COTTON: Do you want to go through the series of things that goes in here?
MR. CLARKE: If you could, yes.
DR. COTTON: The strips go in first and a solution that has some salt in it goes in and your amplified DNA goes in and that is incubated in a water bath so the water bath is controlling the temperature. The water isn't coming over the tray, long enough for your amplified DNA to bind to the DNA dots that are on the nylon. Then a series of reagents or components are added which allow--well, first the extra DNA is washed off and then a series of reagents are added to allow the development on the strip of the blue dot from your DNA bound, so you go through adding your amplified DNA, pouring off any that didn't bind, adding in a series of reagents that you need to develop the blue dots, pouring that off and then allowing them to develop.
MR. CLARKE: And then finally do you see the appearance of these blue dots? As is illustrated, they're the bottom left-hand side of People's exhibit 252, the large diagram?
DR. COTTON: Yes.
MR. CLARKE: All right. Your Honor, at this point I would ask that this exhibit be allowed to be distributed to the jury.
THE COURT: The plastic stray?
MR. CLARKE: Yes.
THE COURT: All right. Dr. Cotton, would you hand that to juror no. 1, please.
(The exhibit was passed amongst the jury.)
THE COURT: All right. Mr. Clarke, would you collect 253 from Deputy Russell, please.
MR. CLARKE: Yes.
THE COURT: And may I see that.
(Brief pause.)
THE COURT: Thank you.
THE COURT: Doctor. Thank you. Mr. Clarke.
MR. CLARKE: Thank you, your Honor.
MR. CLARKE: Dr. Cotton, if you could, could you then turn to the right-hand side of People's exhibit 252. And does that describe a different detection method or typing method when you are looking at these length differences?
DR. COTTON: Yes, it does.
MR. CLARKE: First of all, at the top it seems to have some letters and numbers. What are those?
DR. COTTON: It reads "AMP-FLP D1s80 length polymorphism."
MR. CLARKE: What does that first term mean, AMP-FLP?
DR. COTTON: The "AMP-FLP" is sort of a shorthand version of saying amplified length polymorphism, "amp" referring to amplified, "f" is fragment, "l" is length, "p" is polymorphism. D1s80 is the--is the nomenclature for the genetic location that is currently used in forensic labs that has a length polymorphism.
MR. CLARKE: We will return to that later, but is d1s80 simply a way of describing a particular genetic marker?
DR. COTTON: It is just the name of the marker.
MR. CLARKE: Like PGM is the name of a particular protein marker?
DR. COTTON: Exactly. Exactly.
MR. CLARKE: All right. Go ahead.
DR. COTTON: Okay. So in this case you have amplified DNA. The pieces that you amplified may have different lengths and so you are using a gel, which is our green gel here with the red DNA on it, and the DNA is loaded into the gel. It is a slightly different type of gel than the one I described yesterday, but the principle of how the gel works is exactly the same, and the gel is subjected to electrophoresis and the current moves the DNA through the gel. It moves through based on its size. And in this case you don't have to use p-32, you don't have to do anything fancy after you have run the gel. You can simply use a stain and visualize where the DNA fragments are, so at the end you have a gel that is stained and you can actually see the DNA fragments directly. And then you can photograph that gel and you can compare the positions of DNA bands in the various samples that you have now analyzed.
MR. CLARKE: And that is comparison of the bands like that same process of comparing bands using the RFLP method?
DR. COTTON: It is.
MR. CLARKE: Now, with regard to this length difference and this typing method described on the right, is that again simply one of the means of typing a particular genetic marker following the use of this PCR copying possess?
DR. COTTON: That's right.
MR. CLARKE: As well as this dot-blot method used to look at differences between people, whether it is based on a sequence difference?
DR. COTTON: That's right. With--with the RFLP everything is--you are looking at is length. When you use PCR, you can use a test that looks at sequence differences that is illustrated on the left or you can use a test that looks at length differences and that is illustrated on the right.
MR. CLARKE: One more question, if I could, and particularly while you are up, Dr. Cotton, I would like to take you back to the current drawing, which I believe is People's exhibit 251 labeled "PCR length difference." With regard to that particular drawing, you described the use of these enzymes to cut the DNA at certain locations?
DR. COTTON: I simply made reference to that in that for PCR--scratch that. For RFLP, to define the ends, that is to define the length, you use an enzyme to cut that length out. For PCR, to define the length,--to define the ends, you are using the primers. That defines the end and then you are copying however many repeats happen to be in between. And whether you have a few repeats or a lot of repeats, that determines the length.
MR. CLARKE: And these primers, how do they know exactly where to start this process?
DR. COTTON: The primers don't really know anything, but they are simply a piece of DNA that is single-stranded and they are going in and--and binding with the piece of DNA in the reaction tube that matches them. That is why my short primer example wasn't very good, because to be very specific, the primers need to be longer and they are usually around 20 or possibly more bases.
MR. CLARKE: But for purposes of showing how this process works, that is why you used shorter lengths or shorter sequences?
DR. COTTON: Well, if we drew out all of number of bases we would be here all day.
MR. CLARKE: We would need a taller chart?
DR. COTTON: We would.
MR. CLARKE: Your Honor, it was my intent to clear the charts and enter a slightly different area.
THE COURT: All right. Proceed.
MR. CLARKE: All right.
(Brief pause.)
MR. CLARKE: Dr. Cotton, as far as the use of PCR in your laboratory, was there a time when you actually began using this technique in your actual case work?
DR. COTTON: Yes.
MR. CLARKE: When did that happen?
DR. COTTON: We started doing PCR in case work in about--let me think about this a minute. I believe it was about June of 1992.
MR. CLARKE: And you began using the RFLP process in case work when?
DR. COTTON: Umm, for forensic case work we began about early 1988.
MR. CLARKE: And how do you decide--if a sample or a case comes into your laboratory, how do you decide whether to use the RFLP technique or to use the PCR copying process followed by typing genetic markers that PCR looks at?
DR. COTTON: For our particular laboratory, that may be related to a lot of different things. Umm, for example, it may be that another lab has--had already done RFLP, but doesn't have the capability of doing PCR, so they might specifically be asking us to do PCR. More typically, we would get a piece of evidence in and we would have to make an assessment. Is this piece of evidence--does it have enough DNA and is the DNA in sufficiently good condition to do RFLP? And if so, then you would proceed with RFLP. If the DNA or the piece of evidence contains only a very small amount of DNA or the DNA is very degraded, then you would choose to go forward with PCR.
MR. CLARKE: That is what I was just going to ask next. Do they each have their own advantages, these two different approaches?
DR. COTTON: Yes.
MR. CLARKE: Can you describe that and can you start with RFLP?
DR. COTTON: For RFLP you need a larger amount of DNA and it needs to be in very good condition.
MR. CLARKE: Why is that?
DR. COTTON: Because the test--if you remember yesterday I was talking about lengths of DNA that were thousands of base pairs long. You are looking at--in our lab we are looking at a piece of DNA that is anywhere from about 1500 up to 12,000 base pairs, so your DNA has to be in good condition to even--it has to be much bigger than that as starting material or your test won't work, so it has to be in good shape and you have to have a fair amount of it. The RFLP test has the big advantage in that it is very discriminating from one person to the next. There is so much variation in the population that each time you look at another genetic locus or genetic location with RFLP, you are getting a lot of information. That is, you can discriminate one person from the next with a high level of discrimination. On the other hand, the PCR, the tests that are currently available doesn't have that level of discrimination. It is a much lower level of discrimination, sort of in the range or maybe somewhat better than a whole series of serological markers. However, the PCR can use DNA when you have a very small amount or it is in very poor condition or both.
MR. CLARKE: So in other words, in terms of the ability to tell many of us apart as human beings, in other words, a powerful test as far as this ability to again tell large populations apart, is the RFLP procedure then the more appropriate to be able to determine that type of information?
DR. COTTON: Absolutely. Then that would be the test of choice.
MR. CLARKE: As far as the PCR process itself--and let's talk about both techniques in terms of how long they take to obtain results. Are there any differences between the two?
DR. COTTON: There can be significant differences.
MR. CLARKE: Can you describe that, please.
DR. COTTON: If you brought a sample into the lab and you didn't have--say you didn't have anything else to do, every other case that you were working on was all finished and you simply went through the PCR process, you could have results easily by the end of the week, so it would be very fast. And that is assuming you have, you know, a moderate number of samples, say three or four of something. Easily you would be done in a few days. The same test with RFLP could easily take you three months.
MR. CLARKE: Why is that? Why does it take longer?
DR. COTTON: The length of the time it takes to do the RFLP test is pretty standard from the time you extract the DNA until you load it on the gel, but the exposure of the x-ray film to that nylon membrane, if you have a lot of DNA, it can be short, as short as a day, but if you have little DNA, it can be as long as two weeks. So it could be that for the RFLP test you took two weeks to look at one genetic location, then you took another two weeks to look at the second and another two weeks to look at the third and you can see that rapidly eats up a lot of time.
MR. CLARKE: So it is that exposure of creating this x-ray film that takes a great deal of time; is that right?
DR. COTTON: It can, yes.
MR. CLARKE: Are there differences in the time it may take to create this x-ray from a particular sample?
DR. COTTON: Yes, and the differences are basically related to how much DNA you have in your sample. If you think about a large amount of DNA and a small amount, on your nylon membrane, you add your p-32 DNA probe. If you have a lot of DNA there you can bind a lot of probe. If you only have a little DNA there, you can only bind a small amount of probe. It is the emissions, the radioactive emissions from that probe that expose the x-ray film, so if you have a lot of probe there you will get an exposure on your x-ray film quickly. If you only have a little bit of probe bound because you only had a little bit of DNA to start with, it takes a long time to get enough exposure to that x-ray film to actually see something.
MR. CLARKE: And again, if I can show you what was marked yesterday as People's exhibit 246, is that one of those x-ray films or autorads that can require this fairly lengthy period of time to develop?
DR. COTTON: Yes.
MR. CLARKE: Now, you have described a little bit about the use of genetic markers and you actually identified one of the particular markers and I believe it was d1s80; is that right?
DR. COTTON: That's right.
MR. CLARKE: Is that just simply science's way of designating markers to tell one from another?
DR. COTTON: Basically, yes.
MR. CLARKE: Is there any particular reason there is numbers and letters in it instead of just letters like PGM?
DR. COTTON: The DNA locations that do not code for--do not have information for a gene that we know of, are given letter designations. The "d" stands for DNA. The "1" is because that particular location is on chromosome 1 and the "s80"--I actually can't remember what that refers to--but that also has a specific reference. So--and they are called anonymous DNA pieces, that is, they are not a gene that we know about and they are just given these "D" designations, it is an international nomenclature, so that if I read a journal article and it has one of these probes, it might say D5S20 and that would tell me that that DNA location was on chromosome 5 and if I could remember what the S20 meant, it would tell me more than that.
MR. CLARKE: As far as these genes that you say have these descriptions like starting with a "d" and then a number of the chromosome and so on, you said that something about them was not known. What is that?
DR. COTTON: Most of the--in fact, as far as I know, all of these genetic locations that contain these repeats, these are not genes in the traditional sense. Biologically speaking, in the traditional sense, a gene is a piece of DNA that contains information that creates a protein that then can go out into the cell and has a function. We know that these repeated sequences are not genes in that sense. Scientists don't actually know what the function of these repeats are. That doesn't mean they don't have one; it just means we don't definitely know what it is.
MR. CLARKE: As far as forensic science, and in this process, do you have a process of deciding or selecting which genetic markers to look at for purposes of identifying people?
DR. COTTON: Yes. For all of the markers that are currently used, there has been a substantial development period. That is, of the markers that are available, people have gone in and done the kind of research to say how much variation is there in the population for this marker, how easy is this marker to use, how much development do we have to go through so that many laboratories could have access to this particular marker. So this kind of work is done in a development sort of stage and then a marker is collected because of its utility, its ease of use, its discrimination power and so on, to be then used in--in a wider setting with--where many labs have access to or they choose to use a particular marker.
MR. CLARKE: As a forensic scientist would you, for instance, normally be interested in looking at the cystic fibrosis gene for purposes of your work?
DR. COTTON: No.
MR. CLARKE: Why not?
DR. COTTON: Although there is a lot of variation in the cystic fibrosis gene, that variation isn't widespread enough in the population so that each time you used it you would expect to get very much information. It wouldn't be sufficiently informative for forensic science purposes to use it.
MR. CLARKE: So is it correct then that the genetic markers you are most interested in are those that show us differences between people and can be easily used and are able to be typed, for instance, in older samples?
DR. COTTON: That would be right.
MR. CLARKE: Now, let's go back to PCR itself. Does it have uses outside forensic science or is it just limited to work in an area such as yours like human identification?
DR. COTTON: PCR is sort of the next thing that came along after this southern blot that is used everywhere. The use of PCR in forensic science would be a very tiny fraction of its total utility to biological research.
MR. CLARKE: What are some of the uses of PCR outside forensics?
DR. COTTON: PCR is used in the same kind--in genetic analysis, in gene mapping and it is used in many basic research settings simply because it allows you to get a whole lot of DNA from a very small amount of starting material, and whenever you can Get--scientifically, whenever you can get a lot of something, it gives you the ability to study it, so if you want to look at a particular section of DNA, then to get a lot of it makes you work a lot easier.
MR. CLARKE: You raised the term or you used the term "genetic diagnosis." Is that determining whether an individual, for instance, either has a genetic disease or is I think you used the term a carrier?
DR. COTTON: Yes.
MR. CLARKE: What is a carrier, just briefly?
DR. COTTON: That is if a parent has a genetic disorder, then the parent can transmit that genetic disorder to his or her children and this is something that many parents want to be aware of before they start having children, and you know, so you might say shall I have--a family might decide will we have children or will we adopt children, because one or the other of the parent could be the carrier of a genetic problem.
MR. CLARKE: Is PCR used, for example, to counsel parents, as you have just described, about the likelihood of a child of theirs having a genetic disease?
DR. COTTON: Yes.
MR. CLARKE: Is PCR used in the area of plant genetics?
DR. COTTON: I'm sure it is. I'm not a good enough plant biologist to know any specific applications, but I have no doubt that it is being used.
MR. CLARKE: You used the term "gene mapping." Can you just tell us a little bit about that?
DR. COTTON: In terms of understanding human diseases and human genetics, one of the primary things that scientists need to do or want to understand is how are genes located relative to each other, what gene is on what chromosome, what genes reside close to. And so in the process of figuring this--answering these questions for a specific genes, PCR will be a very helpful technique.
MR. CLARKE: Is PCR used, for instance, in the identification of the remains of American war dead?
DR. COTTON: Yes.
THE COURT: All right. Ladies and gentlemen, we are going to use this point to take a brief Court reporter recess for the morning. Please remember all my admonitions to you. Don't discuss the case among yourselves, form any opinions about the case, conduct any deliberations until the matter has been submitted to you, or allow anybody to communicate with you. And we will resume at ten minutes until 11:00. All right. Dr. Cotton, you can step down.
(Recess.)
(The following proceedings were held in open Court, out of the presence of the jury:)
THE COURT: Back on the record in the Simpson matter. All parties are again present. Let's have the jury, please.
(The following proceedings were held in open Court, in the presence of the jury:)
THE COURT: Thank you, ladies and gentlemen. Please be seated. Dr. Cotton, would you resume the witness stand, please. And why don't you pull the microphone close to you there, please. And, Mr. Clarke, you may continue with your direct examination.
MR. CLARKE: Thank you, your Honor.
MR. CLARKE: Dr. Cotton, you've described a little bit about the use of these tests, whether RFLP or PCR, to exclude people or include people; is that right?
DR. COTTON: That's correct.
MR. CLARKE: Is there any difference between those two things, excluding someone or including someone?
DR. COTTON: Well, those are two different--entirely different things, but I don't--I'm not sure what you mean.
MR. CLARKE: All right. Well, first of all, in excluding a person, what does that mean once you've conducted the test?
DR. COTTON: You've saying that that person cannot be a contributor to the sample that you've tested.
MR. CLARKE: What about the opposite? What about including someone?
DR. COTTON: Including someone, you're saying that this person could be a contributor--contributor to the sample that you've tested.
MR. CLARKE: Is there--in terms of the use of these tests, are they capable and do they in fact serve both of those purposes?
DR. COTTON: Yes, they do.
MR. CLARKE: Now, as far as the use of PCR--and you've described the fact that there are genetic markers or various locations on this DNA molecule that you look at where people differ?
DR. COTTON: That's right.
MR. CLARKE: And you described a little bit about the selection process, the process whereby forensic science decides which markers to look at; is that right?
DR. COTTON: That's right.
MR. CLARKE: Are there specific genetic markers that you look at in your laboratory following PCR amplification?
DR. COTTON: Of course.
MR. CLARKE: Okay. Do they have names that describe them?
DR. COTTON: Yes, they do.
MR. CLARKE: Could you describe those for the jury, please?
DR. COTTON: To tell you the truth, so I don't make a mistake, if you want me to list those markers, how about if you hand me one of my notebooks so I can read off of that.
MR. CLARKE: Sure. Would that assist you in describing each one exactly?
DR. COTTON: I think it would, yes.
MR. CLARKE: First of all--
MR. CLARKE: I'm sorry.
THE COURT: Go ahead.
MR. CLARKE: First of all, Dr. Cotton, these what appear to be two binders, could you just tell us what they are?
DR. COTTON: The two binders have copies in them of our original case folder, and I have the original case folder in my briefcase, but these are easier to manipulate.
MR. CLARKE: In other words, those are easier for you to work with?
DR. COTTON: That's right.
MR. CLARKE: Actually, let me approach it slightly differently. Is there a marker that you examine using the PCR process called DQ-alpha?
DR. COTTON: Yes.
MR. CLARKE: What is DQ-alpha?
DR. COTTON: DQ-alpha is located on chromosome 6 and it is one of the human leukocyte antigen markers. These microphones are doing funny things.
MR. CLARKE: Okay.
THE COURT: Why don't you take it off, take off the wireless, hand it to me.
(The witness complies.)
THE COURT: Thank you.
MR. CLARKE: Now, you used a fairly large term, human leukocyte antigen?
DR. COTTON: That is the name, generic name of the set of genes for which DQ-alpha is one. They are surface--they code for proteins that are on the surface of cells, and DQ-alpha is one of these proteins that's been very well characterized, and the DNA that encodes this protein is also very well characterized.
MR. CLARKE: Dr. Cotton, could you pull that microphone just a little closer to you?
THE COURT: Did you disconnect the Court's microphone?
AUDIO PERSON: Yes, your Honor.
THE COURT: We'll take a recess. Fix it.
(Recess.)
(The following proceedings were held in open Court, out of the presence of the jury:)
THE COURT: All right. Let's have the jury, please. Give me a test on there.
DR. COTTON: How's this sound?
THE COURT: Perfect.
(The following proceedings were held in open Court, in the presence of the jury:)
THE COURT: Thank you, ladies and gentlemen. Please be seated. All right. Let the record reflect we've been rejoined by all the members of our jury. Ladies and gentlemen, I apologize to you for the short delay, but I think you need to hear what's going on. And let's proceed. Mr. Clarke.
MR. CLARKE: Thank you, your Honor.
MR. CLARKE: Dr. Cotton, I believe you were about to discuss this marker called DQ-alpha.
DR. COTTON: That's right.
MR. CLARKE: And is that one of the markers that you type samples at following the use of this PCR copying process?
DR. COTTON: Yes, we did.
MR. CLARKE: What can you tell us about DQ-alpha? How well does it tell people apart?
DR. COTTON: DQ-alpha has six alleles. That is, there's six different forms of this DQ-alpha gene. And with that many alleles or forms, you can generate 21 different types in people. That is, so you're not confused, you--we each have two forms of any genetic locus or any gene. One comes from mother, one comes from father. So you're looking at how many combinations of these six things would exist, and there are 21 different combinations of the six alleles for this gene, DQ-alpha.
MR. CLARKE: Is there a particular term used in science to describe what a person's type is when they have two forms of a particular genetic--added to a genetic marker?
DR. COTTON: Yes.
MR. CLARKE: What's that called?
DR. COTTON: I mean--I think you're talking about are the term homozygous and heterozygous.
MR. CLARKE: All right. Well, let's start with that first. What do those terms mean? Are they--are they important? Do we need to know those terms?
DR. COTTON: Do you need to know them? Well, I don't know if you need to know them. Probably you do. When you have inherited from both parents the same form of a gene, that is so both your copy that you got from your mother and the copy you got from your father are identical, then you would be said to be homozygous, homo meaning the same and zygous referring to a zygote, which is combination of egg and sperm. So if you have two forms--you will always have two forms of the gene. And if they happen to be the same--let's use a very easy example. If you got a gene for blood group a from your mother and you got a gene for blood group a from your father, you would have two genes. Both are for blood group A, and you would be homozygous for that a.
MR. CLARKE: All right. Is there also a term called "genotype"?
DR. COTTON: Genotype simply--it just means what types do you have. Do you have an a and an a or an a and an B. That's your genotype, AA or AB.
MR. CLARKE: As far as this marker, DQ-alpha is concerned, if everyone in the courtroom were tested, would each of us be one of these 21 different types or genotypes?
DR. COTTON: We would each be one of those 21 types.
MR. CLARKE: Does that mean because there are presumably more than--well, there are more than 21 people in this courtroom. Does that mean it's likely or necessarily true that at least two of us have the same genotype?
DR. COTTON: Well, probably for those genotypes or combinations of genes that are common, we'd find more than one person in the courtroom who had the same type.
MR. CLARKE: That was actually going to be my next question. As far as these types that we each have, are they distributed absolutely equally or not?
DR. COTTON: They're not.
MR. CLARKE: Why is that?
DR. COTTON: I don't think we can--first of all, I'm not sure I can answer that question. That may be an evolutionary answer, and I'm not that knowledgeable about the DQ-alpha gene. However, what I know is that the types are not distributed evenly. So some types are very rare, some types are relatively rare and some types are very common.
MR. CLARKE: We'll return to it later, but are there studies done to determine how common or how rare these individual types are?
DR. COTTON: There actually is a very large amount of work published on how common or rare particular DQ-alpha types are in many different racial or ethnic groups.
MR. CLARKE: Still, with this DQ-alpha marker, how do you know it's a good marker to use in forensics?
DR. COTTON: Well, if you use as your Judge the first criteria that you want something to be relatively variable, that is a marker that shows a lot of variation is more useful than a marker that doesn't show very much variation. So on that criteria, DQ-alpha is quite good because with six alleles giving you 21 different types, that's a fair amount of variation and it's going to have useful information. The test that has been designed for forensic use for DQ-alpha, which uses PCR, only amplifies a very short section of DNA. That means the test is going to work well on samples that are degraded; and so for that reason, it's also very good.
MR. CLARKE: Is it, for instance, more useful than the ABO blood grouping types that this jury has already heard about?
DR. COTTON: Yes, it would be.
MR. CLARKE: Why is it more useful?
DR. COTTON: It has more variation.
MR. CLARKE: In what way?
DR. COTTON: Well, with ABO blood groups, you have three choices of alleles. You can be an a--you can be A, you can be O or you can be B, and that gives you a combination of six different genotypes; that is, taking those three things two at a time. So that means one--each one of us will be one of those six types as opposed to DQ-alpha where each one of us would be one of these 21 types. So DQ-alpha is going to be able to distinguish us one from the other better than ABO.
MR. CLARKE: Incidentally, of the six types for ABO you've described, are they actually type--fewer than that that can be actually determined from testing?
DR. COTTON: With normal serology testing, you can't distinguish all those types. People are developing DNA tests in which you will be able to distinguish all of those types.
MR. CLARKE: All right. In addition to DQ-alpha, do you type other genetic markers following the use of PCR?
DR. COTTON: Yes.
MR. CLARKE: And are they collected--first of all, how many other markers do you type in the laboratory?
DR. COTTON: In our laboratory, we're typing--well, we're typing five other markers. Actually, recently, we've added three more, but they were not done here and we don't need to worry about those. So for purposes of this case, we typed five additional markers besides the DQ-alpha.
MR. CLARKE: Are those five markers collectively known by any term?
DR. COTTON: The five markers are collectively referred to as poly-marker or PM, and that's simply the name given to those--that's not a scientific name really. It's just the company who developed this test refers to it as PM, generally standing for poly-marker.
MR. CLARKE: And are there different ways of describing those five different markers that are part of the poly-marker system? In other words, are they labeled by a particular name?
DR. COTTON: Yes. The five genetic locations that are tested in this poly-marker system, each one has a specific name.
MR. CLARKE: And can you briefly describe what each of those five are in terms of their name?
DR. COTTON: Sure, but this is what I'm going to take out of my notebook here. So--
MR. CLARKE: All right.
THE COURT: All right. Mr. Neufeld, you want to see that?
MR. NEUFELD: Thank you.
DR. COTTON: I'm just going to read this section here.
(Discussion held off the record between Mr. Neufeld and the witness.)
DR. COTTON: That I can do too.
THE COURT: All right. Mr. Clarke, proceed.
MR. CLARKE: Yes. Thank you.
MR. CLARKE: Dr. Cotton, what are those five--five genetic markers?
DR. COTTON: Each one of them has a short abbreviation which stands for the longer name. If you just focus on the abbreviation, that's probably a lot easier. The five markers are LDLR standing for low density lipo protein receptor.
MR. CLARKE: Can we stick with LDLR?
DR. COTTON: You want me just to give the initials?
MR. CLARKE: That's fine.
DR. COTTON: Okay. The other is GYPA, the third is HBGG, the fourth is d7s8 and the fifth is GC.
MR. CLARKE: Now, of those five you just described, one of them had that notation of the letter "d" with a number; is that right?
DR. COTTON: That's right.
MR. CLARKE: Would that then be another one of those markers where its function in the body is unknown?
DR. COTTON: As far as I know, it is, yes.
MR. CLARKE: And then the other four were described by letters basically; is that right?
DR. COTTON: The other four are actually genes and they have--the letters are just an abbreviation for the name of the protein that's been very well described for that gene.
MR. CLARKE: Now, this set of five markers that are part of poly-marker, how do you know they're good to be used or appropriate to be used in forensic work?
DR. COTTON: Each one of these markers doesn't--does not have a lot of variation, but grouped together, it still is informative. And really, the answer to your question is, in addition to the theoretical idea of how informative is this marker, this test has been designed to be also useful specifically for forensic purposes. The sections of DNA that are amplified are small and the typing is on the dot blot strips that you saw in the tray a while ago. So it's a test that's easy to do in the laboratory and it works on a--and has been shown to work on a very wide variety of samples. So it's applicable to all kinds of samples that come in in terms of forensic casework.
MR. CLARKE: Incidentally, that tray with the strips that you identified and was shown to the jury, was that actually a poly-marker set of typing strips?
DR. COTTON: Yes. The strips that were in the tray when you looked at them have the five poly-marker loci. And if you were looking at the strip, you would see that there were letters on the top of each one, and it's the LDLR, GRPA, indicating the dots in that set of the--in that portion of the strip or for that particular genetic location.
THE COURT: All right. Referring to People's 253.
MR. CLARKE: Yes. Thank you, your Honor.
MR. CLARKE: Going back to DQ-alpha for a moment, how long has it been used in forensic casework?
DR. COTTON: I think since about 1986.
MR. CLARKE: Going forward then to the poly-marker genetic markers, when were they begun to be used in forensic casework?
DR. COTTON: We started using the poly-marker test in January of 1994. There probably are some other labs who were using it earlier than we do, but I don't know exactly how--it wouldn't have been a lot earlier. Somewhere maybe within a year or so before we did. So let's say it's been being--it's been used in forensic casework since approximately 1993.
MR. CLARKE: Is there some process that these genetic markers undergo before they're actually used in casework or did someone just discover a gene and start using it immediately?
DR. COTTON: There's actually a very--what usually ends up being a very long process of development of the marker and then what's referred to as validation. That is, if another laboratory uses a marker, that doesn't necessarily mean that I can just bring it into my lab and start using it. So each lab that uses a particular test generally goes through a set of experiments in their laboratory to make sure that in--in the hands of the people in that laboratory, the test functions as it's supposed to, it meets its specifications and that everybody that is using it understands what it is they're doing. So there's development of the marker, then there's validation of the marker, which may occur in many different labs, and then there's training the staff in a particular lab to use that--that marker.
MR. CLARKE: And do you ensure that that marker can be correctly typed in evidence type samples before you even begin casework use of them?
DR. COTTON: Of course.
MR. CLARKE: As far as these poly-markers--well, let's start with DQ-alpha. Is DQ-alpha a marker that's tested--and I think you said more than one laboratory uses the poly-marker system. What about the DQ-alpha system?
DR. COTTON: The same is true of the DQ-alpha system. It's used by many forensic laboratories around the country and really around the world.
MR. CLARKE: That was going to be my next question. To your knowledge, are the poly-marker and DQ-alpha genetic markers used worldwide?
DR. COTTON: They are.
MR. CLARKE: You touched a little bit about as far as the five poly-marker genetic markers, that their variation is not as great as DQ-alpha?
DR. COTTON: That's right.
MR. CLARKE: Without getting into each one individually, can you tell us briefly how much variation that each show?
DR. COTTON: The five locations that make up the poly-marker system, all of those five locations either have two or three alleles or forms and they're all--they--they all are designated a or B, and if they have three forms in the kit, they're designated A, B or C. So you can--for example, if you have a marker that has an a type and a B type, any given individual then could have two A's, they would be an AA, they could have two B's, they would be a bb or they could have an a and a B and they would be an AB. So if you have two alleles, the most number genotypes you can have is three.
MR. CLARKE: DQ-alpha and these poly-marker genetic markers, do they represent sequence differences or length differences as you described them earlier today?
DR. COTTON: These are all sequence differences.
MR. CLARKE: As far as the actual typing of these DQ-alpha and poly-marker genetic markers, do you actually conduct these tests from scratch in terms of materials and what you use to be able to type samples?
DR. COTTON: No.
MR. CLARKE: How do you do it?
DR. COTTON: These tests, the DQ-alpha and the poly-marker, come as a kit, which means, you're buying in a box all the things that you need or almost all the things you need to do the test. Actually, you'd end up making a few solutions in the laboratory. But the strips come in the kit, the chemicals that you need to do the reaction, to create the blue dots come in the kit, the tray comes--you have to buy the tray and the kit. I guess actually you buy them separately. And the PCR mix that contains the primers and the polymerase and the a', G's, T's and C's. All that comes in the kit. So you're just supplying some very simple to make solutions and using the kit to do the test.
MR. CLARKE: When you conduct the more powerful RFLP typing technique, do you use kits to do that?
DR. COTTON: No.
MR. CLARKE: Why is there a difference between the two approaches to DNA typing as far as kits are concerned?
DR. COTTON: Well, somebody took the time to make the kit for DQ-alpha and poly-marker and nobody has tried to market a kit for RFLP testing. I guess you could, but it would have an awful lot of components.
MR. CLARKE: Is there anything unusual about using kits to conduct testing?
DR. COTTON: Oh, no.
MR. CLARKE: Why do you use a kit?
DR. COTTON: Because it's there.
MR. CLARKE: Does it have--
DR. COTTON: It's a good test and it's available and it's had an enormous amount of work done on it. If it wasn't a good test, you wouldn't use it. If it wasn't available, obviously you couldn't use it. So the company that makes the kit has put a lot of work into it and it happens to be very, very good.
MR. CLARKE: All right. Turning your attention if I can to the last genetic marker that we will talk about, d1s80, does that represent a genetic marker that's typed based on length differences as opposed to sequence differences?
DR. COTTON: Yes.
MR. CLARKE: Was DNA--I'm sorry. Was d1s80 developed as a marker to be used for forensics or did it have some different origin?
DR. COTTON: As far as I know, it was--it wasn't discovered--I mean it was discovered, but then basically it was developed specifically for forensic use. I really don't know if there's any research use for d1s80 or not.
MR. CLARKE: Outside forensics?
DR. COTTON: Right.
MR. CLARKE: How are you familiar with this particular genetic marker?
DR. COTTON: We've run this marker in our lab. We're not currently using it in our routine casework, but we've run it in our lab, and I've also actually read a number of papers that had to do with d1s80 and heard a lot about it at various scientific meetings.
MR. CLARKE: Why don't you use it in your casework in the laboratory?
DR. COTTON: The reason we're not using it in our casework is not because it's not a good marker. It's a very practical reason; and that is, the kind of gel that the d1s80 is run on is not a kind of gel that we would run other markers on. And so essentially, we aren't using it because it's a fair amount of work to do it and you get one piece of information off, that is the d1s80 piece of information. There are some other markers out there that we chose to use instead. They're not quite as informative as d1s80, but I can do more of them at a time. And so it was a very practical decision that you would just make in the lab to say, "do we want to do test a or test b?" It has nothing to do with whether or not d1s80 is a good marker. It was just our choice to go with another type of marker.
MR. CLARKE: So there are practical considerations that go into each laboratory's decision of what markers they're going to test?
DR. COTTON: That's right. And because not every--not every laboratory that does casework has the same type of casework or the same casework demands. And so all of those things go into your decision about what markers you're going to be using.
MR. CLARKE: As far as your familiarity with this d1s80 marker, what type of variation does it show?
DR. COTTON: The d1s80 has over--at least 24 alleles. That is at least 24 forms. I don't--haven't calculated how many genotypes that could give you, but you can imagine 20--at least 24 things taken two at a time. You can have many, many, many combinations. So it's a very informative marker and it's--except for the gel system, which takes some pains to do, it's a very good one.
MR. CLARKE: All right. I would like to shift topics if we can and ask you, are you familiar with the term "contamination"?
DR. COTTON: Certainly.
MR. CLARKE: What does that term mean to you?
DR. COTTON: It means so many different things that maybe I should try to break them down in terms of what it means to me.
MR. CLARKE: All right.
DR. COTTON: If you think of a biological sample, say you take a blood sample from someone in sterile conditions, you have a very clean sterile sample. That's sort of the ultimate in a good--in terms of having a good sample. As soon as you take that sample out of a sterile condition and say you have a bloodstain on a piece of cloth and you could think about well, that bloodstain is no longer sterile and it could be, quote, contaminated by anything that's on that cloth. So that would sort of be a second or let's say a first level. Now, in terms of analyzing evidence from a crime scene, you're always getting things that are like that. You're never being presented with a sterile sample. So in terms of a crime scene, contamination would mean that the sample is as it--that is, in retrieving the sample, it is as it was deposited, that nothing's been added to that sample in the process of picking it up, taking it to the crime lab and so forth. And then you can also say, "well, I have my sample from the crime scene. It came to the crime lab in exactly the same condition that it was at the crime scene." And then clearly, you need to be concerned with whether or not in the process of working with that sample in the laboratory, are you introducing any contamination from any source in the laboratory. So you can't use it very well as a generic term. I mean, you could, but unless you specify what kind of contamination you're talking about, then it becomes very difficult to discuss because you can--you can break it down and you can have many different kinds of contamination, some of which are inherent in the fact that you have a piece of evidence and not a sterile blood sample and some of which are not inherent and that could occur along the way in how that sample is handled.
MR. CLARKE: As a forensic scientist, are you concerned about contamination?
DR. COTTON: Of course.
MR. CLARKE: Why?
DR. COTTON: The idea of analyzing a piece of evidence is that you learn something about that piece of evidence. You're not interested in learning about-- that is, if you contaminate that piece of evidence with--let's talk about, say, you contaminate a piece of evidence with some other biological sample or some DNA in the laboratory. You--that will then interfere with your being able to come to a valid conclusion about that piece of evidence. And so you would certainly prefer not to have anything interfere with coming to a valid conclusion about a specific piece of evidence.
MR. CLARKE: As far as this area of contamination--and you've described the two basic DNA typing approaches that you use, both RFLP and PCR--is your concern about contamination the same for both of those techniques or is it different?
DR. COTTON: It's different.
MR. CLARKE: Why?
DR. COTTON: The PCR test is much more sensitive. You can do a PCR test with a very minute amount of starting material. So you would be more concerned. It doesn't mean you're not concerned with contamination for RFLP, but you're going to be more concerned with contamination when you're dealing with doing a PCR test on a piece of evidence.
MR. CLARKE: Okay. Let's take RFLP to start with. What steps if any do you take to deal with the problem or the potential problem of contamination in that testing process?
DR. COTTON: Okay. And what I'm--my answer is going to then be what we're doing in the laboratory because we're simply receiving a piece of evidence from outside. That is, we're not collecting the evidence ourselves. In the laboratory, our work is done in a--it's called a biological safety cabinet, but basically it's a setup where you have a piece of glass and you have a working area and the air is circulated within that working area to both protect what you're working on and to protect yourself. So you have some containment in the area that you're working with these samples. In our laboratory, when a sample is moved from one tube to another, that is, the tube has a label, it has a case number label and a sample number label, when it's--and in the process of doing DNA extractions and doing this testing, there are points where you have to remove the sample from one tube and put it into another. That transfer--the labeling on the tubes is witness. That is, somebody is checking to make sure that if I'm transferring from a tube that's marked 02, then I'm transferring it--the second tube I have in my hand is also marked 02. The other main precaution is that we do the DNA extractions for evidence samples as opposed to known samples. That is, when I say known, I mean you have a standard sample from a known individual. Those extractions are not done out in--well, they're done in this hood, but they're not done at the same time. So the knowns and the evidence samples are not worked on for purposes of DNA extraction at the same time.
MR. CLARKE: So those are the primary steps undertaken with regard to the potential for contamination as far as RFLP typing is concerned?
DR. COTTON: That's right.
MR. CLARKE: What about PCR? Do you undertake any different steps or additional tests to deal with this potential problem?
DR. COTTON: There are many additional features of how you do a PCR test to deal with minimizing any problems with contamination.
MR. CLARKE: Could you describe those, and are there general categories that you can place them into as far as the steps that you take?
DR. COTTON: I'm not sure what you're asking.
MR. CLARKE: Well, what are--what are the steps you take to deal with this potential problem?
DR. COTTON: Okay. The--let me think about this a second so it comes out organized. The PCR--the DNA extractions for PCR are done in a separate location than the extractions for RFLP. Now, in our lab, it happens to be that there's a separate one of these biological safety cabinets that's only used for PCR extractions. And the reason for that is that if you're doing something--if you have enough DNA to work with RFLP, that's a fair amount of DNA compared to what you might have in a PCR sample. So we don't want to be handling the large quantities of DNA that you can--that you would have for RFLP in the same place with the same equipment that you're handling the very small amounts. So most laboratories will have a separate location to do DNA extractions when those DNA extractions are for PCR. And in our lab, it's a separate--one of these hoods. The sample is--and in addition to that, for example, in the hood, the pipette-man or the, you know, the piece of equipment you're using to add things to the sample and take things out of the sample are specified. That is, you have a pipette-man that's used only for DNA and you have a series of pipette-man's that are used for everything else, so that you're not interchanging the piece of equipment that you're using to handle the DNA. You are that concerned. And the tips that you're using for the pipette-man are these art tips that have a filter in them so that you can't get any part of your sample up into the pipette-man and, therefore, accidentally transfer it to the next thing that you work with.
MR. CLARKE: Now, I believe--did you talk about extraction--I'm sorry--extracting evidence?
DR. COTTON: Well, basically that's--everything I just said relates to the area where the DNA is extracted.
MR. CLARKE: All right. Extraction was the first basic phase of dealing with evidence for purposes of PCR typing; is that correct?
DR. COTTON: That's right.
MR. CLARKE: Earlier, you described the second major phase involves what's called amplification, this copying process.
DR. COTTON: That's right.
MR. CLARKE: Do you take any precautions or additional steps to again deal with the potential for contamination during this particular phase?
DR. COTTON: Yes.
MR. CLARKE: What are those?
DR. COTTON: Well, first--now that you've finished the extraction, you want to set--you're going to set up the amplification. That is, you go through that process where you have a tube, and in that tube, you put your DNA and you put all the things you need to do the PCR, the primers, the polymerase and so on. That set up is done in a second area, a very clean area, and it's--in our lab, it happens to be a very small room, but it could--it could be some other just separate location. So the set up of the PCR reaction is done away from where the DNA extraction is done. Once that reaction is set up, it's then carried to yet a third location where the thermal cycler is where the amplification takes place. Once it's gone into that area where the amplification takes place, it does not ever go back in the other direction.
MR. CLARKE: Why is that?
DR. COTTON: I think about--in terms of the PCR, you have started with a tiny amount of material, and now after the process of amplification, you've generated millions of copies of that tiny amount of material. The biggest contamination problem that can occur with PCR is transferring some of that amplified product back to where you're starting out with, because that amplified product will amplify really well if it gets into anything else. So the--it's not the only concern, but the biggest contamination concern is that you do not get any of that amplified product, which is now a lot of DNA, back into anything that you're ever starting out with. So the DNA samples go from the extraction area to the set-up area, to the area where the thermal cycler is and where you then do the analysis of the amplified product and they do not go back in the other direction.
MR. CLARKE: And that's to, again, avoid this problem of lots of DNA being mixed in or commingled with small amounts of DNA?
DR. COTTON: That's right.
MR. CLARKE: Now, as far as--and I believe you described the fact that evidence is not extracted at the same time as known samples or did you mention that?
DR. COTTON: I did mention that with regard to RFLP testing, and the same--that same general procedure. That is, you don't do the DNA extractions for evidence and knowns at the same time. That's just a general precaution we use in our laboratory, and it's applied to everything.
MR. CLARKE: So as far as RFLP typing, your primary steps to avoid contamination are extracting samples at a different time, that is knowns versus evidence; is that right?
DR. COTTON: That's right.
MR. CLARKE: As well as witnessing of labeling samples; is that correct?
DR. COTTON: That's right.
MR. CLARKE: And are those the two primary steps taken as far as RFLP testing is concerned?
DR. COTTON: That's right.
MR. CLARKE: When you turn to PCR, you utilize those same two precautions; is that right?
DR. COTTON: You utilize those same two precautions and the other long list of precautions that I just talked about.
MR. CLARKE: As far as this case--and you described a little bit about the amplification phase. Was it correct that evidence samples in this case were amplified or did it happen that they were amplified on a different date from known samples?
DR. COTTON: In this case, it happened that that's the way the testing was done. Not only were they, the DNA extractions, done at a different time, but the amplifications, that is putting the tubes in the thermal cycler and allowing the amplification to take place, that also was done at a different time for the knowns and the evidence samples. That's not necessarily the--the way every case is worked. It just happened to be the way this case was worked really based on when we received samples and when we did each one.
MR. CLARKE: Does that play any role in the potential for contamination at all?
DR. COTTON: Well, it certainly acts as a preventative measure.
MR. CLARKE: But it's not something that you deem to be routinely necessary?
DR. COTTON: That's right.
MR. CLARKE: As far as these precautions--and let's focus on PCR for the moment. The precautions that you've described that you use in the laboratory, are they unique to forensic science or are they used in other areas of science involving PCR?
DR. COTTON: They are definitely not unique to forensic science because every lab that's using PCR, no matter what the reason, is still doing the same thing. They're taking a small amount of DNA and making millions of copies of it. So any laboratory that uses PCR for any reason has got to be concerned with making sure this amplified DNA that they get at the end doesn't get transferred back to any--any place along from the start of the sample on forward.
MR. CLARKE: Are these measures taken, for instance, in laboratories diagnosing diseases?
DR. COTTON: Certainly.
MR. CLARKE: Or in research laboratories?
DR. COTTON: In research laboratories also.
MR. CLARKE: Or in laboratories conducting paternity case evaluations or testing?
DR. COTTON: Exactly. And I'm not--I'm not--I don't mean to imply that, for example, a research laboratory would take exactly the same precautions that we would. They may be slightly different. But no matter what the setting is for PCR, you have to be concerned about making sure amplified product doesn't get back to your starting point.
MR. CLARKE: I'm sorry. Could I have just a moment, your Honor?
(Discussion held off the record between the Deputy District Attorneys.)
MR. CLARKE: So in terms of these--and just in terms of summarizing, these precautions that you take for PCR, they include the way you handle evidence; is that right?
DR. COTTON: Yes.
MR. CLARKE: The way you extract evidence in terms of when it's done at a same or different time than known samples in a case?
DR. COTTON: Yes.
MR. CLARKE: It includes precautions taken with regard to instruments that you use?
DR. COTTON: Yes.
MR. CLARKE: As well as the direction of flow so to speak of a sample going in one direction only as you described and not backwards?
DR. COTTON: That's right.
MR. CLARKE: As well as--and incidentally, are there other steps taken that to your knowledge we'll discuss later as well in terms of dealing with the potential problems of contamination?
DR. COTTON: Yes.
MR. CLARKE: Now, I'd like to shift topics a little bit to specific forensic case samples that are encountered. And in particular, with regard to evidence, can evidence at, for instance, crime scenes be subjected to basically the environment and the elements in that environment?
DR. COTTON: I don't think it's a question of "can." I think it's a question of that's absolutely bound to happen.
MR. CLARKE: Okay. What types of things can happen, for instance, to a piece of evidence found outdoors?
DR. COTTON: Well, it's going to be exposed to whatever temperatures are outdoors, whatever lighting conditions. There may be a lot of sunlight on that day. Could get rained or snowed on. I mean, whatever--if it's outside, it's going to be exposed to whatever's going on outside from the time that it was left there until the time that it's picked up.
MR. CLARKE: Incidentally, would the same be true, for instance, of a soldier killed in battle, out in a battlefield?
DR. COTTON: I would presume so.
MR. CLARKE: Or dead animals?
DR. COTTON: Dead animals too.
MR. CLARKE: You've described a little bit about, for instance, heat. Would that represent one instance of an environmental effect or something that's possible that happens outside?
DR. COTTON: Sure.
MR. CLARKE: And would that include sunlight as well?
DR. COTTON: Yes.
MR. CLARKE: And I think you mentioned rain or perhaps--
DR. COTTON: Well, I mean, you said outside. So I said, well, it could get rained--I mean, in California, maybe not, but--
MR. CLARKE: Sometimes. Some seasons it does.
THE COURT: You would be surprised.
MR. CLARKE: How about humidity? Is that something else that happens?
DR. COTTON: Of course.
MR. CLARKE: Are there other types of influences that are out there outside?
DR. COTTON: Well, I think you've named the major ones.
MR. CLARKE: With respect to these influences or effects like heat, humidity, rain and so forth, what do they do to DNA? What's their effect on DNA?
DR. COTTON: Basically, all of those things over time will act to gradually degrade the DNA; that is, break it up. The generalization that--that most everybody is aware of is that dry and cold works to preserve DNA and warm and moist works more towards degrading DNA. That's just a generalization, but that's pretty much the case.
MR. CLARKE: We'll talk about storage of samples in just a few moments. But is there anything about these environmental effects, whether sunlight, humidity, rain, et cetera, that can actually change DNA from one type to another?
DR. COTTON: No.
MR. CLARKE: How do you know that?
DR. COTTON: Well, you know that at a relative--at a very basic level because these things will not change the DNA sequence. Light, heat all of these things will not result in changing the DNA sequence. If you think about the kinds of locations that we're testing, we're testing lengths of DNA. Suppose you're doing an RFLP test and we're using my DNA and I have a DNA fragment that's 5,000 base pairs long. Degradation of DNA is a random process. There's no method or no enzyme that can go in from an environmental perspective and say, we're going to take that 5,000 base pair piece and it will then be converted to a 3,000 base pair piece, just a nice clean thing, goes from 5,000 to 3,000. That isn't what happens. Degradation is random. So that 5,000 base pair piece as it degrades is going to be cut up in many different places. And so it just gradually gets smaller and in many different sizes. So there is no environmental force, there is no environmental effect that can work to simply change one type and make it become another. You may lose the type altogether. You may degrade the DNA so much that you can't type it. But you won't just change types from one to another. Doesn't happen.
MR. CLARKE: Let's talk a little bit about storage. And you mentioned briefly about drying and--I'm sorry--making a sample cold as being a means or a method to preserve DNA?
DR. COTTON: Yes.
MR. CLARKE: Can you describe a little bit more about that? Why is that the case?
DR. COTTON: Problem with moisture--with high temperature and high humidity is that that enables bacterial growth, and bacterial growth will result in the DNA becoming degraded. That's generally the problem with high temperatures and humidity. Dry conditions and very cold conditions inhibit any kind of bacterial growth. And so they tend to be very good for storage. And keep in mind, unless your sample is sterile, sterile meaning the presence of no bacteria whatsoever, then any moisture and any heat will promote bacterial growth and that bacterial growth will gradually degrade the sample.
MR. CLARKE: What if you don't, for example, refrigerate or freeze a particular sample of DNA? What happens?
DR. COTTON: Well, it sort of depends on what stage it's at. If you're just at the evidence stage where you have some stain on some piece of clothing or some other substrate, then you really will see different effects with moisture and heat. Once your DNA is extracted--and it's really very clean. You don't have bacteria in there anymore. They've been destroyed in the extraction process. You may have bacterial DNA, but you don't have living bacteria. They've been destroyed. And so once your sample of DNA is purified, it does store over time best if it's kept cold. It's usually stored at minus 70 or minus 20 degrees centigrade. But if you left it out on the bench top at room temperature, you could really leave it out there for a very long time before it would be useless.
MR. CLARKE: Your work in the laboratory includes the receipt of certain--paternity samples for paternity tests; is that right?
DR. COTTON: Yes. The laboratory's work does.
MR. CLARKE: How do you receive samples for paternity testing?
DR. COTTON: We receive samples for paternity testing usually by federal express, and they're usually drawn from the individuals that are going to be tested the day before, they're packed up in a Styrofoam container so they can't break, they're shipped at ambient temperature, whatever temperature the air is, and received by us usually about 24 hours later.
MR. CLARKE: And are these in the form of liquid blood in tubes?
DR. COTTON: Yes. They're usually liquid blood drawn into EDTA tubes.
MR. CLARKE: Are these shipped--now, you mentioned the term, they're stored at ambient temperature, whatever temperature the outside is?
DR. COTTON: Well, that is, when they're given to federal express. Federal express isn't putting them in a refrigerated vehicle. So they may be flown to us or come in a truck. But whatever temperatures happen to be in that truck or the plane or, you know, all the various things it's going into before it's delivered to us, that's the temperature they're at.
MR. CLARKE: Does that create any problems in your ability to type these samples?
DR. COTTON: No, it doesn't.
MR. CLARKE: What happens, for instance, with one of these liquid blood samples? Well, let me rephrase that. Do you in the course of testing even in your forensic casework, that is identification casework other than paternity, do you receive samples in a liquid blood form?
DR. COTTON: Sometimes.
MR. CLARKE: Are they maintained in any condition as far as refrigeration in terms of their shipment or what they're shipped in?
DR. COTTON: If we're receiving a liquid blood sample for a forensic case, it's usually shipped in the same manner. Occasionally it's hand-delivered. Mostly, it's sent by some kind of carrier like federal express.
MR. CLARKE: What can happen to these liquid blood samples? What do you see in your casework that can happen as far as the ability to type DNA?
DR. COTTON: Well, it makes a big difference. If we're talking about liquid blood samples drawn from a known living individual, they're usually drawn in the same way the paternity samples are shipped to us and they're just fine. There are other types of blood tubes that you can draw people's blood into that have other types of preservatives other than EDTA. Those other types of preservatives are not as good for maintaining the condition of DNA as EDTA is. That's absolutely the--that's the preferred way for us to have a blood sample.
MR. CLARKE: Go ahead.
DR. COTTON: Well, I was just going to say, if the blood sample's from someone who's died, then you would be more concerned to make sure that it had been cool--it had been stored properly and that it had been drawn in an EDTA tube.
MR. CLARKE: Is that because blood taken from dead bodies is subject to this degradation process in a much faster fashion or faster fashion than blood from a living individual?
DR. COTTON: Yes.
MR. CLARKE: If blood is degraded in a liquid form, whether it's from a sample from a Coroner's office or paternity sample or another sample that you received in liquid condition, is there anything about that degradation process that can change the types of the sample involved?
DR. COTTON: No.
MR. CLARKE: What happens when it degrades? Is it the same as happens to, for instance, a stain that you described maybe outdoors?
DR. COTTON: Yes. It's the same.
MR. CLARKE: Now, as far as other things that exist out in the outside or in the environment, are there any in particular that can create a problem in your being able to type the DNA in that sample itself?
DR. COTTON: Any sample that is sufficiently degraded can be so degraded that you can't type it by any of the typing methods that are currently available. And there's an exception to that. It's typing of what's called mitochondrial DNA, which is DNA that is not in the nucleus. And that is the absolute last resource. That is, if the sample is in such bad condition, you can't do anything else with it, you might be able to do mitochondrial DNA, and there not very many places that will do that, that have that capability.
MR. CLARKE: As far as what's out there so to speak in the outdoors, what about soil? Does it play any role in the ability to type DNA?
DR. COTTON: Samples that are retrieved from soil are very difficult to type. Frequently you do not get any result.
MR. CLARKE: Why is that?
DR. COTTON: Presumably, you have bacteria in the soil that are participating in degrading the DNA. However, I don't know of a definitive experiment that's shown specifically that it's bacteria. So I only can tell you because this is the common experience, it's in the literature and many labs have had this experiences, if they are taking a blood or semen stain from soil, their success rate with those samples is very, very low.
MR. CLARKE: What about leaves? Are leaves another item similar to soil?
DR. COTTON: Yeah. Leaves aren't good either.
MR. CLARKE: Would your answer as far as the reason why be the same as soil?
DR. COTTON: It would.
MR. CLARKE: Is there anything about the presence of soil or leaves that could change the types that are found in a particular DNA sample so that they would be typed differently from what the contributor of that DNA actually is?
DR. COTTON: No.
MR. CLARKE: As far as laboratory precautions that you take again--and we're--and let's focus, if we can, on PCR typing, the precautions that you described earlier--is it a danger, for instance, if someone's coughing around a sample? And let's refer to an analyst.
DR. COTTON: Okay. So what you're asking me is, if I have a piece of evidence and I'm going to do PCR analysis on it and somebody's coughing, could that present a problem?
MR. CLARKE: Exactly.
DR. COTTON: It's possible. It's not--I don't think it's real likely, but I can't tell you it's impossible.
MR. CLARKE: What about sneezing?
DR. COTTON: Well, if you make it generic and say if I as the analyst transfer any of my cells onto the sample, then I could create a problem with that sample. But you have to think how much material you're transferring to that sample relative to how much material is there in the sample already. So it's--there's not a very--there's not a black and white answer to that question and there may not be a simple answer to that question. I--there is an experiment in the literature where they actually tried to contaminate a sample by the way the sample was handled, and it didn't cause any problem. That doesn't mean that it would never cause a problem. So you do want to be concerned about it, but you shouldn't assume it will cause a problem absolutely every time something like that occurs.
MR. CLARKE: In particular, are you referring to a publication in the scientific literature directly addressing the potential for problems as a result of some of these items we just discussed?
DR. COTTON: Yes, I am.
MR. CLARKE: Who wrote that publication?
DR. COTTON: The authors on that publication are Kate Comey and Bruce Budowle from the FBI.
MR. CLARKE: Could you spell both those last names?
DR. COTTON: I think Comey is C-O-M-E-Y and Budowle is B-U-D-O-W-L-E.
MR. CLARKE: And did that publication specifically deal with this question of whether or not these various influences could affect the ability to correctly type DNA samples?
DR. COTTON: Yes, it did.
MR. CLARKE: What conclusions did they come to?
DR. COTTON: The conclusion that they came to was that careful routine handling--
MR. NEUFELD: I'm sorry, your Honor. I'll object to the conclusion that they came to.
THE COURT: Sustained. Hearsay.
MR. CLARKE: As far as your reading of that publication, did that lead you to render any conclusions in your own mind about the appropriate way to deal with samples that are obtained, for instance, at crime scenes?
DR. COTTON: It contributed to my thinking about that, yes.
MR. CLARKE: Did it corroborate what your opinion was before you had even read the publication?
DR. COTTON: Well, at the time that I read the publication was during the time we were just starting PCR. So it added to my thinking, which was sort of still being formulated.
MR. CLARKE: Incidentally, as far as a stain let's say at a crime scene, to your knowledge, is there any reliable method of determining how old that stain is?
DR. COTTON: Not to my knowledge.
MR. CLARKE: As far as these environmental influences--actually, let me rephrase that, if I may, your Honor. As far as these items that we discussed, touching--well, sneezing, coughing, et cetera, do you have a personal opinion about their impact on your ability to properly type DNA samples that have been subjected to PCR amplification?
DR. COTTON: Yes, I have an opinion.
MR. CLARKE: What's that?
MR. NEUFELD: Objection. Foundation.
THE COURT: Sustained.
MR. CLARKE: With regard to these various impacts--well, let me rephrase that if I can. As far as your own experience in the laboratory with testing samples--and I'm referring to evidence samples--has that included samples obtained from a variety or under a variety of different circumstances?
DR. COTTON: Of course.
MR. CLARKE: How long have you been engaged in that? How long have you been in the laboratory gaining this type of experience?
DR. COTTON: Well, when I--when you say "you," really we're referring to my whole lab staff. Since about--well, since before 1992. We did a lot of work. We did a lot of validation work before we actually began to use PCR in casework. So we have the experience from the validation work and from the casework.
MR. CLARKE: As far as in the laboratory--and I'm going to direct your attention in particular to sample handling; for instance, extraction, amplification and typing of DNA--have you examined the results from your casework since you've used PCR in your laboratory?
DR. COTTON: Yes.
MR. CLARKE: Do those results include certain steps to determine if in fact the process of using PCR and then typing it is leading to or is actually including foreign DNA being typed in samples? Is that question clear?
DR. COTTON: I think so. There is a--
MR. NEUFELD: Excuse me. I still have an objection both as to vagueness in the question and secondly, again, foundation because we don't know whether it's to samples that are coming in--
MS. CLARK: This is a speaking objection.
THE COURT: It is a speaking objection.
MR. NEUFELD: Sorry.
THE COURT: Overruled. Also, a comment by counsel not handling the witness. Mr. Clarke.
MR. CLARKE: Do you recall the question?
DR. COTTON: You want to start over?
MR. CLARKE: Sure. As far as this actual PCR typing process that's gone on in your laboratory, do you take steps to detect whether or not there may be DNA present that you're able to determine types from that didn't come from a particular evidence sample?
DR. COTTON: Yes.
MR. CLARKE: Does that involve the use of controls?
DR. COTTON: It does.
MR. CLARKE: What is a control?
DR. COTTON: A control is some kind of sample that you use alongside your other samples or at some point in the process, again, to help you determine whether or not your process has worked correctly and whether or not you have a valid result.
MR. CLARKE: All right. We'll return to the nature of the controls that you utilized in the laboratory a little bit later. But do those controls provide you with an opportunity to determine whether or not foreign DNA; that is, DNA that's not part of the sample, is being injected into the process?
DR. COTTON: They help to answer that question, yes.
MR. CLARKE: All right. And has that gone on since DNA, that is PCR type DNA testing has gone on in your laboratory?
DR. COTTON: Yes.
MR. CLARKE: With regard to these potential influences like coughing, sneezing and touching, do you have an opinion about your ability to detect them as far as if they have any impact on your typing of evidence samples?
DR. COTTON: Yes.
MR. CLARKE: What's that opinion?
DR. COTTON: With regard to handling the samples from the point of the extraction forward, the controls will allow you to determine whether anything that you're doing has had an impact on that sample. Obviously we can't make any determination regarding what's occurred to the sample before it comes in our laboratory because then the sample is as it is. We don't have any experience in our laboratory of picking up in a sample control the types of the analysts who have handled that sample.
MR. CLARKE: So it's been your experience in your laboratory that these considerations, these things that can happen simply don't happen in your laboratory?
DR. COTTON: It's been our experience that we are not detecting them happening in our laboratory. As far as we can tell, they are not impacting on the analysis from the point that we get the sample.
MR. CLARKE: All right. Your Honor, I was going to shift gears again.
THE COURT: All right. Ladies and gentlemen, we are going to take our recess for the morning. Please remember all of my admonitions to you; please don't discuss the case amongst yourselves, don't form any opinions about the case, don't conduct any deliberations until the matter has been submitted to you, do not allow anybody to communicate with you with regard to the case. And we'll stand in recess until 1:00 o'clock. All right. I would like counsel here promptly at 1:00 o'clock. All right. And, Dr. Cotton, you may step down.
(At 12:03 P.M., the noon recess was taken until 1:00 P.M. of the same day.)
LOS ANGELES, CALIFORNIA; TUESDAY, MAY 9, 1995 1:01 P.M.
Department no. 103 Hon. Lance A. Ito, Judge
APPEARANCES: (Appearances as heretofore noted.)
(Janet M. Moxham, CSR no. 4855, official reporter.)
(Christine M. Olson, CSR no. 2378, official reporter.)
(The following proceedings were held in open Court, out of the presence of the jury:)
THE COURT: Back on the record in the Simpson matter. All parties are again present. The jury is not present. Mr. Clarke, you indicated there was a matter that we should take up before we proceed with Dr. Cotton.
MR. CLARKE: I'm sorry, your Honor, were we going to proceed on the two items, that is, the instruction as well as the mixture?
THE COURT: I'm more interested in the mixture aspect.
MR. CLARKE: Okay. With the Court's permission, Mr. Harmon has been preparing a response to that. The Court may recall I had to do it on fairly short order last Friday, and with the Court's permission, I would like him to address this issue.
THE COURT: All right. Good afternoon, Mr. Harmon.
MR. HARMON: Good afternoon, your Honor. Perhaps the best starting point, that in terms of the mixture results that we have obtained on numerous items in this case, we have never intimated that any of those items match anything. And I know that the Court has been concerned about language from legal opinions talking about evidence of a match without a statistic is meaningless. These are not matches; these are results which are consistent with or in another context that the sources have not been excluded by the testing that was done. One could imagine a scenario where you have two rapists and only one of them is identified and a victim identifies that person and both assailants have raped the victim and both have ejaculated and DNA typing of either is done and it is clear that there is a mixture or a combination, more than one sperm donor, and we only have one Defendant at the end of the table and his type is consistent with the mixture that was obtained there.
It is the People's position in this case, even though that that is not directly on point, that that sort of evidence could be presented and explained to the jury what it means and what it doesn't mean, without assigning any statistic to it. The Court was interested in any legal precedent on the issue. I don't think there is any legal precedent that says that we have to do what the Defense wants us to do in this case, and I think that is the appropriate question to ask, what is the legal precedent that forces us to do what they have sought or what they are seeking in this case? There is legal precedent in the conventional serology area that points out that we don't have to do what they have asked us to do, and not coincidentally, one of those cases is a capital case that I tried, I was the Prosecutor in, People versus Wash, 6 cal.4th 215. I can speak from personal experience and also relate what is in the opinion, because this is what happened in every sexual assault case where conventional serology was done.
THE COURT: Mrs. Robertson, 6 cal.3d, please.
MR. HARMON: Where conventional serology was performed, and we haven't heard much about an aspect of DNA typing that dramatically changed forensic analysis, that is in DNA typing it is possible to separate the male DNA from the female DNA in sexual assault cases and that is why in sexual assault cases DNA typing of any form is a very powerful tool. Before DNA typing came along it was impossible to separate out the male biological material from the female biological material. And in each and every sexual assault case the evidence was presented as a failure to exclude, and People versus Wash stands for that proposition. What People versus Wash does not stand for is the proposition that the Defense is arguing in this case that has never been applied in conventional serology, that in those sexual assault cases, in order to present any of our results of a failure to exclude, we would have to sum up all of the possible combinations of the biological markers of both the male and the female. And so I point that out because there is a total amount absence of any legal issue on that point. We were never compelled to do that. We didn't do it in wash. It was not done in another California Supreme Court case dealing with sexual assault evidence, People versus Ashmus. It is impossible to separate out biological markers.
THE COURT: How do you spell that?
MR. HARMON: A-S-H-M-U-S. The cite is 54 cal.3d 932. So I just point that out because they don't say we don't have to do that, but they do stand for the proposition that the same arguments could have been applied and were not applied in that situation. I think it is important to look at where this issue first came or became injected into this case. I'm not sure who wrote this brief, but it is replete with references to Professor Thompson where he wrote his own brief and then cites things that he has published on this article or in the article. If you recall--and this began on page 21 and it spanned several pages, if you recall, the argument was first broached in an admissibility context. The evidence would not be admissible unless. And if you recall, the initial argument was that what I would not--we should not be allowed to report, if we had a mixture that clearly came from more than one person, that we should not be allowed to say, aha, we see one of these people in there and the frequency for that one person is ten percent. And that was never our intention. Our board does not have frequencies. That--and so the argument--
THE COURT: There is no frequencies as to mixtures.
MR. HARMON: As to mixtures. As to mixtures.
THE COURT: All right.
MR. HARMON: Then--
THE COURT: You are only seeking to report that as a failure to exclude?
MR. HARMON: We are seeking to report the data, and I will get to that in a minute, why that is important, and if there are innocent explanations for this, we would love to hear what they are, but I will discuss the data in just a second. Mr. Or Professor Thompson's brief then goes on to claim that there is nothing about the forensic context, there is nothing about the observations in these tests that can allow a scientist to assign relative proportions or to sort out what is clearly a mixture. And that is all well and good. That is what Professor Thompson says, but he is not a Professor in forensic science. The Defense's own primary PCR consultant, the fellow whose name I keep mentioning, Dr. Blake, has published extensively on interpreting mixtures by relative intensity. And I think it is important to keep that in mind. I doubt we will be seeing him in this case, so this is the most that we can hear from him, but let's--an article, I think it is the case work article in the journal of forensic science by Edward Blake, Jennifer Mihalovich, M-I-H-A-L-O-V-I-C-H, Russ Higuchi, Sean Walsh and Henry Erlich at page 706. Dr. Blake and his colleagues say: "the detection of mixtures depends in part on the fact that any one individual can have at most two alleles of a given gene. The presence of more than two alleles in a sample indicates a mixture. Even if only two alleles are present, a mixture can still be detected if the two samples are mixed in different proportions. In this case, a mixture is suspected if the relative dot intensities corresponding to the two alleles are different."
And then he goes on to describe other things that appear in sexual assault cases. Later on at page 722 in the same article Dr. Blake again discusses mixed genotypes. "another issue that has arisen in some cases is the ability to analyze mixed genotypes in biological evidence," and then the passage discusses how you can do that. Probably the most instructive article by Dr. Blake, it is a chapter in a book--chapter 17--unfortunately I don't have the title of this book--it is called "applications of PCR to the analysis of biological evidence." It is by Cecilia von Beroldingen, and that is b-e-r-o-l-d-I-n-g-e-n, and Edward Blake, Russ Higuchi, George Sensabaugh and Henry Erlich. And in that chapter Dr. Blake has a very interesting case work example, and I will just paraphrase it. It is a sexual assault case where the victim had had consensual sex with her husband, I think nine hours prior. And when the evidence was analyzed, a sample--you always try to obtain a sample from the last consensual sex partner in a sexual assault case just to make sure that what you are getting is what you think you are getting. And in this case Dr. Blake not only sorted out by relative intensity and found a much bolder pattern for the person who was accused of the crime, but he said, well, there is a fainter pattern there and that is consistent with the husband. And then Dr. Blake, in this mixture, did something that we don't seek to do in this case, he calculated the frequency for the bolder pattern, because that was the assailant in the case. Why sum up when you know where the other stuff came from, the DNA pattern from the victim's husband? So while it is easy for whoever wrote that brief to say you can't do that, there is neither the law on their side to say that we can't do--all we are doing is we say here is a mixture, here are the alleles that we saw, here is the data that we saw with no frequencies. Now, it is--for example, there are two series, I think, and specifically with respect to the Department of Justice results, there are three stains on the center console of the Bronco. They show a clear mixture. There is more than two alleles. And what is clear is that the mixture could not be from Mr. Simpson alone because there is more than one person clearly there. What is also clear is the mixture just happens to contain alleles from the two victims in this case. We turn the table a little bit when it comes to the glove, and I'm just talking about the PCR context of this glove. On the glove, by both RFLP and PCR we've got--there are discreet stains that type very powerfully to Mr. Goldman and nobody else. Very powerfully. The frequencies or the estimates in that are in the millions. There are others which are combinations of both Nicole and Ronald and those were typed by both PCR and RFLP and there are relative intensity differences in both the RFLP and PCR results in those cases. And that is all part of the forensic picture on this case. So when it comes to several stains that are right around the notch area where we see these consistencies, we see something that is inconsistent with the two victims in this case that we have proven very powerfully are there, and among the three people that were involved in this case, it is only consistent with Mr. Simpson. And that is all the jury--that we want to tell the jury. To preclude us or to try to present some sort of estimate about--that calculates a meaningless expression, there is simply no legal basis for it and it is totally contrary to the Defense's leading expert on this area whom we will probably never see in this courtroom, Dr. Blake. I think finally, we've gotten the cart before the horse in this case. We have boards. They have launched an objection. I think they are the moving party in that instance, your Honor, and all they have said is you have to do something. I have demonstrated and I will be glad to provide copies of those articles, that there is a scientific basis for us to do what we want to do. They have not demonstrated that there is no scientific basis. I think it would be appropriate at this point--they have never suggested what those frequencies should be in this, and I can tell you, having dealt with statisticians, that you can define a different question that will change the number. I would suggest, and all we are asking to do is we want to present our results to people who are anxious to hear the results of this typing. The Defense does--and there are no statistics on those boards. It has always been our intention with mixtures not to present statistics, but to explain the results fairly, equivocally and unambiguously and let the jury decide what they mean. The Defense, on the other hand, wants to force us--this is the narrow legal issue that has allowed me to speak for fifteen minutes--the Defense wants to force us to put a meaningless number up there that they can either elicit on cross-examination--we know they can't call Dr. Blake on this point--but to call somebody else to do that.
And I think it is time to move on with the trial and deny their objection to this, or the alternative is to force them to sustain their burden of proof that there is both a legal and a technical objection to it and at that point we will be happy to point out, in or out of the presence of the jury, why we should be entitled to present the results in the form that we would like to present them.
THE COURT: Mr. Harmon, when do the People anticipate getting to actually presenting these results?
MR. HARMON: Could Mr. Clarke address that, because he is up now?
MR. CLARKE: As far as the results board themselves--
THE COURT: And specifically the mixtures.
MR. CLARKE: --I will anticipate that we will start the viewing of autoradiographs but not get as far as the results that are at issue, the mixtures.
THE COURT: This afternoon?
MR. CLARKE: Correct.
THE COURT: All right. Mr. Neufeld.
MR. NEUFELD: Thank you, your Honor. Well, I think what you do have here, your Honor, is an attempt, at least by Mr. Harmon, to selectively present statistics to this jury. And frankly, in the words of Marcia Clark, what is really going on here I think is an effort on their part to mislead, distort and confuse the jury by doing so. And in response to Mr. Harmon's suggestion that there is no legal authority to the contrary, there is. People versus Barney, in the first department they said explicitly that if you want to present DNA evidence you do so with statistics, otherwise it has no evidentiary value. And your Honor adopted that same ruling in the Court's opinion on the DNA objections on April 7 of 1995. Dr. Blake, by the way, who Mr. Harmon refers to, routinely in trial case after trial case aggregates in mixtures the various genotypes and always gives a sum. That has been his standard practice. We have seen him do it in more than a dozen cases and that is the procedure in fact used by serologists and geneticists all over the country, as far as we know. It is also the policy and practice adopted unequivocally in the national academy of science inquiry into the proper usage of DNA testing.
THE COURT: Do you want to cite me to the page?
MR. NEUFELD: Yes, I will give you the page. One second.
(Brief pause.)
MR. NEUFELD: Umm, on page 59 it says, and I quote: "if a suspect's pattern is found within the mix pattern, the appropriate frequency to assign such a `match,'" unquote, "is the sum of the frequencies of all genotypes that are contained within that mix pattern." Okay. So that is what they are saying. I have never seen any scientific authority any place to the contrary. It is the standard practice used by professional serologists and geneticists, when testifying to the results of a mixed stain, that I am aware of. I would also point out, your Honor, and I don't--I don't want to spend much time on it, but you may recall when we brought up this issue last week with you, you said if they had any legal authority to the contrary that it should be given to the Court last Friday and given to counsel last Friday. I asked again whether there was any authority yesterday and I was told there was none and all of a sudden Mr. Harmon comes in here to present his argument and for the first time we are hearing references to legal authority. And I don't believe that this is consistent with the instructions that you have given, not only in this particular issue, but all issues that have come before your Honor during the pendency of this case. I don't even know, because I haven't seen those cases yet, whether or not this specific objection is even raised. Did the trial lawyers say that it was error to admit the evidence in the absence of statistics and was that issue precisely addressed on appeal and resolved by the appellate Court? I don't even know if the cases even stand for the proposition that Mr. Harmon is suggesting, but you do have legal authority here and the legal authority is Barney. And in the conventional serology cases, your Honor, are not terribly useful on this point because Barney was decided in the context of the power of DNA evidence, certain cache that comes with saying you have a DNA match. And we all know that outside this courtroom that we are talking about things like uniqueness or an extremely rare possibility. We are not talking about items such as 1 in 20 or frequencies of 1 in 40 in conventional serology.
We are talking about much, much rarer instances here, and it was because of that that the Court in Barney decided that unless you say what that match is or what that inclusion is--and by the way, whether you call it a match, or in a mixed stain context an inclusive, you are basically saying the same thing. In fact, Robin Cotton earlier today was asked to address exclusions and inclusions and was very clear from what she said that when you are talking about inclusions you are talking about that so-called match. And I think you even ruled in the past that they are free to use those words interchangeably when describing the--the concurrence of data in a particular DNA profile. And so what we are saying is and what the Court basically ruled in Barney is it is a foundation issue. It is a foundation issue. You cannot present evidence of an inclusion or a match, whether it is an in a mixed stain or any other type of stain, unless along with it you give the jury some--some generally accepted view of the statistics of that. Now, you have already ruled that they are allowed to give estimates based on the product rule and they are not required to use some other approach, but at least they should be required to use that same product rule that they used for getting frequencies on these single-source stains to the mixed stains. And there is a very straightforward way to do that. It is the way that is described in the NRC report. It is the way that any experienced scientist would do it. You simply look at the different frequencies, they could be the frequencies that some authority has for those different genotypes, and you aggregate them. It is as simple as that, otherwise you really do mislead the jury. I gave you an example the other day of one mixture that they would present through cellmark diagnostics and that is a mixture on the steering wheel in the Bronco. If you have these--these--these other types of evidence where you are saying there is an inclusion and it includes Mr. Simpson or it includes someone else, and you then have a number for that match and you give it a number of one in a million or one in a billion or whatever and then in the very next item you say we have this mixed stain and it also includes Mr. Simpson, but we don't give a frequency for that, then under 352 the likelihood of confusing the jury and leading them to infer that that match has the same power as the match just above it is extraordinary. And in the example I gave, your Honor, the percentage of the population which would not be excluded by that mixed stain profile on the steering wheel is about 38 percent of the population. Now, that is a far cry, just on a gut level, from the kind of power that we ordinarily attribute to DNA testing and that is why Barney says you have to give a statistic. That is why the NRC stays you have to give a statistic. And frankly, I believe that is why you said it in your decision last month and I am simply asking that the same thing be accorded to the People at this time.
THE COURT: All right. Thank you, counsel. All right. Mr. Harmon, I haven't had the opportunity to read the case law that you have cited to the Court. I will read that. And since we are not going to get to those results this afternoon, I will have the evening to think about.
MR. HARMON: Okay.
THE COURT: All right. Let's proceed with the jury.
(Brief pause.)
(The following proceedings were held in open Court, in the presence of the jury:)
THE COURT: All right. Thank you, ladies and gentlemen. Please be seated. Dr. Cotton, would you resume the witness stand, please.
Robin Cotton, the witness on the stand at the time of the noon recess, resumed the stand and testified further as follows:
THE COURT: The record should reflect we have been rejoined by all the members of our jury. Good afternoon, ladies and gentlemen.
THE JURY: Good afternoon.
THE COURT: Dr. Robin Cotton is again on the witness stand undergoing direct examination by Mr. Clarke. Good afternoon, Dr. Cotton.
DR. COTTON: Good afternoon.
THE COURT: Doctor, you are reminded you are still under oath. And Mr. Clarke, you may continue with your direct examination.
MR. CLARKE: Thank you, your Honor. Good afternoon, ladies and gentlemen.
THE JURY: Good afternoon.
DIRECT EXAMINATION (RESUMED) BY MR. CLARKE
MR. CLARKE: Dr. Cotton, you spoke just before the lunch break about the use of cells and I believe you briefly described what their purpose is. Could you state again why controls are used in testing?
DR. COTTON: In general you are using controls to help ensure at the end of the analysis that the steps worked as they should, that is, an example of that would be you have a type for a PCR analysis and you've typed that sample many times and so you type that sample along with your evidence samples and you make sure that the type that is expected from this one sample you've typed many times comes out as it should. If it doesn't, it tells you that something could have gone wrong during the analysis procedure.
MR. CLARKE: As far as RFLP testing and the use of controls, when you--if I ask you later to examine and describe an autorad or a series of autorads, will you be able to point out the control on that autorad?
DR. COTTON: Yes.
MR. CLARKE: Then let's turn to PCR typing and the use of controls. Do they play the same or in any manner a different role in PCR typing than they do in RFLP typing?
DR. COTTON: There is one of the controls that is used in PCR that basically plays the same role as the controls in RFLP and there are two additional controls that are done that sort of play slightly different roles in the PCR procedure.
MR. CLARKE: What role does--does the use of controls have in this PCR typing process? Why do you use them?
DR. COTTON: You use them to use one known sample to ensure that the procedure worked as it should, and you use two different negative controls, that is, controls that do not have any DNA in them, and they--one of them starts at the very beginning of the procedure and then one of them starts at the point that you set up the amplification, and they are in there to control that in your handling of the evidence and known samples that you didn't add any DNA inadvertently in the processing for the PCR. And there is actually one other type of control that is done with PCR, but may not be done in every instance, and that is if you have a, umm, say, a stain on a garment, you might take an unstained portion of that garment and have that go through the process also. The interpretation of that control, should you get something, may be somewhat difficult, and if you don't get anything, then it just says you didn't have anything in this one area that you tested.
MR. CLARKE: All right. The first type of control that you described was a control with a known type of DNA in it for PCR typing?
DR. COTTON: That's right.
MR. CLARKE: And then you also described and you used the term "negative controls." Does the negative control name come from the fact that there is no DNA in them?
DR. COTTON: That's right. The known sample that you are typing is called a positive control. That is, you are putting DNA in there and you know what that result should be. The negative control you are purposefully starting with a blank tube, adding your PCR reagents, but no DNA, and therefore, since you are not adding any DNA, you shouldn't get any result.
MR. CLARKE: And then you also said that there was a fourth type of control?
DR. COTTON: Well, there is a third type in our lab that is called a reagent blank control. That control is started at the time you are putting your evidence into the tube. You are carrying alongside of that a blank tube. So let's say we have tube 1 and tube no. 2 and in one you are putting your evidence. In tube no. 2 you are not putting anything in there, but then in the process, for example, of doing the DNA extraction, you are adding some things to your evidence so you are also adding them into the empty tube, so it is a way to make sure that everything that you added to your sample did not have any additional DNA in it.
MR. CLARKE: All right. Dr. Cotton, what I'm going to ask you to do, with the Court's permission, is to on a single piece of drawing paper is to describe or list these controls used in PCR typing.
DR. COTTON: Okay.
MR. CLARKE: Would you be able to do that?
DR. COTTON: Sure.
MR. CLARKE: All right. Your Honor, may that then be marked as, I believe, 254?
THE COURT: 254.
(Peo's 254 for id = drawing)
THE COURT: We will title this "controls"?
MR. CLARKE: "PCR control" if that would be appropriate.
THE COURT: All right. Dr. Cotton, if you would oblige us again.
(Brief pause.)
THE COURT: Mr. Clarke.
MR. CLARKE: Yes, thank you.
MR. CLARKE: Dr. Cotton, if you would, could you label this particular piece of paper "PCR controls."
DR. COTTON: (Witness complies.)
MR. CLARKE: And I believe that you had described that the first control was a control with a known type of DNA in it?
DR. COTTON: That is the first one that I mentioned.
MR. CLARKE: And I think you used the term "positive control"?
DR. COTTON: Yes.
MR. CLARKE: All right. Could you write "positive control"?
DR. COTTON: (Witness complies.)
MR. CLARKE: And if you would describe again what its role is in this typing process.
DR. COTTON: Positive control contains a known DNA sample that has been typed many times so the type for this known sample is--is known, so you have a known DNA sample. You carry that, that is set up at the point the amplification is set up, and it is carried through the rest of the typing procedure. If the types in that known sample do not come out as they should, it would be an indication that something had gone wrong in that analysis step--in the series of steps that you have used.
MR. CLARKE: In other words, you know what the type of that positive control is and if you don't detect that type at the actual portion of the test where you determine types, then you know something has gone wrong?
DR. COTTON: That's right.
MR. CLARKE: All right. What was the second type of control that you described?
DR. COTTON: The second type I described was a negative control.
MR. CLARKE: And is there one or more than one negative control used in each test?
DR. COTTON: There is really at least two and possibly a third type, all of which could be considered to be a negative control, but we give them different names, so that we don't get confused.
MR. CLARKE: Okay. Then you have listed under "negative control"--there is then two versions of a negative control?
DR. COTTON: Well, it depends if you want to call it a substrate control. That is a version of a negative control also.
MR. CLARKE: Okay. If we could, we will talk about substrate control separately so--
DR. COTTON: Okay.
MR. CLARKE: --ignoring that for the moment, could you describe the other two types of negative controls used in the test?
DR. COTTON: Okay. One of them we are just going to call the negative control and that is set up when the amplification is set up, and the same is true of the positive control, it is set up at the time the amplification is set up. And what I mean by that is that you have extracted your DNA and now you are carrying it into a separate area and you are putting it in a tube and all the--and the PCR mix, the polymerase and the primers and so forth. This negative control is set up at that time and this positive control is set up at that time and this negative control has everything added to it that all the other samples do, except there is no DNA in there at all.
MR. CLARKE: What do you mean when you say it is set up at the same time? What does that term mean?
DR. COTTON: Simply that you are putting the things you need out on the bench so that you can work with them and you are physically going through the process of taking your tube for sample no. 1, putting in the PCR mix, putting in the DNA. You actually put some oil in these samples also, and then setting that tube aside and going on to the next one.
MR. CLARKE: Why do you use this negative control? What is its purpose?
DR. COTTON: The PCR components themselves, the mix that has it in the primers and the enzyme and the A's, T's, G's and C's, that could possibly be contaminated with DNA if it were not handled properly, so this is--all of these negative controls are a way to make sure that everything you are adding to the sample is free of any extraneous DNA.
MR. CLARKE: What happens in the typing process if you determine that in your negative control, for instance, are types that shouldn't be there?
DR. COTTON: Generally, and I'm saying generally because there may be an occasional exception in a laboratory to this, but generally if your negative control comes out with a type, you would disregard all the results for that test and go back and repeat the test.
MR. CLARKE: Okay. Is there then a second, as you described, type of negative control?
DR. COTTON: Yes. And in our lab that is referred to as a reagent blank control.
MR. CLARKE: What does that control consist of?
DR. COTTON: It consists of everything that was added to the evidence from the beginning of the analysis. If you break the analysis down into DNA extraction and then go up to amplification, in both those procedures you are adding things to your evidence samples or to your known samples. So this control makes sure that when you add things to the PCR set-up, those reagents--those components don't have DNA. And the reagent blank control does the same thing, but goes back as far as the DNA extraction and let's you assess whether or not in adding things to the evidence to perform the DNA extraction, that you are not inadvertently adding some DNA in there.
MR. CLARKE: As far as inadvertently adding DNA, again, how does this control perform that process?
DR. COTTON: (No audible response.)
MR. CLARKE: Actually perform that role?
DR. COTTON: Let's say you have a tube in front of you and you are beginning to do your DNA extraction and you are adding some solution, that is a chemical solution, it might have salt, it depends on how you are going to do your DNA extraction, you want to make sure that that solution that you are adding hasn't any DNA in it. So everything that you add--I don't know how else to say it--everything that you add to the evidence gets added to this Bronco tube, so at the end, if you have DNA in this blank tube, that tells you that you would have been the--the same things that got added to that blank tube also got added to the evidence. It tells you you might have inadvertently added some DNA containing cells to the evidence.
MR. CLARKE: And if you see results in this negative control, or you actually see types, what does that tell you?
DR. COTTON: If you saw a full blown type, you would certainly declare the results of your analysis inconclusive. There--there--for most instances, if you saw something in the reagent blank, you would declare your results inconclusive. I can think of a few examples of when you wouldn't do that or you might consider not doing that, but in general that would be what you would do.
MR. CLARKE: So is this then a third alert to you of potential problems?
DR. COTTON: Yes. That each one of these controls is an alert to you of a problem that could have occurred and it helps you sort out where that problem could have occurred.
MR. CLARKE: And I also believe you said there was a fourth control as well or actually a third type of control, but a fourth control?
DR. COTTON: If you do a substrate control, that is another type of control.
MR. CLARKE: On these typing strips themselves, is there an additional control?
DR. COTTON: On the typing strips themselves there is a dot which needs to appear in order to assure you that you had enough amplified DNA to get a reliable result.
MR. CLARKE: As far as these dots, do they alert you to the potential of problems in this typing process, and I'm referring to the dots that you just described?
DR. COTTON: The control dots.
MR. CLARKE: The control dots, yes.
DR. COTTON: They don't alert you to a problem. They alert you to the fact that they say you had enough DNA in your sample, that is, you had enough amplified DNA in your sample and the results on this strip are reliable because you can see this control dot. If you don't see the control dot, it may mean that you are missing some types. You may see some types, but you can't be assured that you are seeing every type that could be there.
MR. CLARKE: As far as these controls--or that control dot, was that in fact present on the typing strips that were passed around to the jury earlier, although bearing in mind that those strips had not been developed?
DR. COTTON: Yes. The control dot on the strips that were typed (Sic) around is designated with an "s" and you wouldn't have seen it because they haven't been developed, but where there was a designation for an "s." That is where the control dot would be.
MR. CLARKE: Your Honor, if we may, I would like to ask the witness in this subject area some brief questions, and the exhibit is People's 252, one of the large charts.
(Brief pause.)
THE COURT: All right. Would you like Dr. Cotton to remain there?
MR. CLARKE: No. Actually, I think, Dr. Cotton, if you could just stand by and not get hit by the chart.
(Brief pause.)
MR. CLARKE: All right. Thank you, Mr. Fairtlough.
THE COURT: Mr. Clarke.
MR. CLARKE: Thank you.
MR. CLARKE: With regard to this chart, Dr. Cotton, People's exhibit 252, the strips that we see on the left-hand side of this diagram, those are strips that are used to type what genetic marker?
DR. COTTON: These--the strips that are depicted here are for typing the DQ-alpha marker.
MR. CLARKE: And on those strips is there a specific location where the control dot is that I just described?
DR. COTTON: Yes.
MR. CLARKE: Could you point that out, please?
DR. COTTON: It is just to the right--my right of the C here, (Indicating), so this dot that is between the C and the no. 1.1, this is the control dot.
MR. CLARKE: And is that the dot that then performs that function or role that you just described when you were writing on the diagram, People's exhibit 254?
DR. COTTON: Yes.
MR. CLARKE: Is there a similar dot then on the strips used to type the five polymarkers?
DR. COTTON: There is and it has a designation as an s dot, but in fact it is made up of the same components and it performs exactly the same function as the C dot.
MR. CLARKE: All right. Very good. Thank you. Dr. Cotton, you also described or used the term "unstained control." Was it?
DR. COTTON: I may have said this or I may have said substrate control.
MR. CLARKE: All right. Does that item or that term have a particular meaning to you?
DR. COTTON: Yes, it does.
MR. CLARKE: What is that?
DR. COTTON: It would be a--best example I can think of is a stain on a garment would be a portion of that garment that did not have any apparent stain which you could then type and use that to help you interpret your results on the stained portion of the garment.
MR. CLARKE: In what way? How does that assist in the interpretation of any results from a stained portion?
DR. COTTON: Well, it may assist in that that--the control portion may not have any type at all and that would just be a general indication that the garment itself--usually the control is taken very near the stain so I'm not thinking about taking a control on one shoulder and then looking at other stain on another shoulder. So you are taking the control near where the stain is and you are saying, well, I don't have any additional DNA besides what I'm seeing and therefore what I'm seeing from the stain is probably all the DNA that is there. I mean, the other obvious result is that you've got a type from your control section and that might mean, for example, suppose someone had worn a shirt for a very long time, you know, a week or something. You might actually pick up some of that person's type who had worn the shirt for a week on a control section. You might see that type reflected in a stained section as well, so it would just be information on the condition of the surrounding area of the stain.
MR. CLARKE: Why would you be able to see a person's type on a garment that had been worn for some time?
DR. COTTON: Because you may have skin cells that if you have worn a garment for a really long time may have adhered to the fabric and you may have a sufficient number that you would actually see a type. Now, I haven't done an experiment on this but I have just used this as an example.
MR. CLARKE: All right. As far as these unstained or substrate controls, as you have just described them, do they play any role in determining whether or not contamination of a sample may have occurred?
DR. COTTON: It doesn't--well, actually, yes, it would help you to determine that as well. If you picked up a type on the unstained portion, the other explanation, other than what--either that type existed on that unstained portion at the time it was collected or it had been deposited on there somewhere during the processing. And there is no way you could be able to distinguish which of those two scenarios had happened. It would just alert you to either the thing had DNA on it when you started, or some extraneous DNA may have gotten on it during the processing and you couldn't tell the difference.
MR. CLARKE: How often do you receive unstained or substrate controls in case work at cellmark?
DR. COTTON: I don't know how to give you an exact figure. We receive them some of the time. Most of the time we do not.
MR. CLARKE: As far as all of these controls that you have described, do they all represent different versions of basically lights that can be lit or alerts to you about the potential for problems?
DR. COTTON: That is exactly right.
MR. CLARKE: Now, turning in particular to the strips, and these are these PCR-type strips--and I believe just a few moments ago you pointed to a DQ-alpha typing strip and then you also--or we also showed to the jury a polymarker typing strip; is that right?
DR. COTTON: That's right.
MR. CLARKE: These results, and I believe you have already described this, are actually read visually, that is, a person looking at them and deciding where there are positive results and where there aren't; is that right?
DR. COTTON: That's right.
MR. CLARKE: And by positive results--
DR. COTTON: Blue dots.
MR. CLARKE: Blue dots. Does one person simply read those results in the laboratory to determine what the types are that are present?
DR. COTTON: Well, not in our laboratory, and I can't speak for every laboratory. Every laboratory that does this does not have exactly the identical procedure. In our laboratory the evidence samples are read by two individuals. If you are doing a known sample, that sample may only be read by--only needs to be read by one person, but any evidence sample gets read by two people.
MR. CLARKE: As far as these results themselves, are they maintained--do the strips still exist, for instance, if you want to look at a case a day later, a week later, a year later and so forth?
DR. COTTON: The strips still exist and you could go look at them, but they are not the best permanent record of the results because the blue color in the dots can fade over time.
MR. CLARKE: What steps, if any, do you take to record these results at the time that they are read so that they can be looked at later?
DR. COTTON: There is two things that are done. The strips are read visually by two different analysts and those readings are recorded on paper and the strips are photographed and those photographs are maintained in the case file.
MR. CLARKE: Are those photos then provided, for example, to Prosecutors in cases?
DR. COTTON: Yes.
MR. CLARKE: Are they provided to the Court, for instance, on occasion?
DR. COTTON: They are provided--there are two original photos that are taken. Generally we maintain one and the other one is provided to the Court or to the Defense or to the Prosecution, whoever is in need of that copy.
MR. CLARKE: Does that allow those results then to be reviewed at a later time by any of those people you have just described?
DR. COTTON: Yes.
MR. CLARKE: Or even by experts retained by either side?
DR. COTTON: That's right.
MR. CLARKE: Now, I would like to turn our attention, Dr. Cotton, to an area frequently referred to as proficiency testing. What is proficiency testing?
DR. COTTON: Proficiency testing is generally the receipt of samples in a laboratory where the samples are sent from an agency or an organization who is engaged in providing proficiency tests. And it is just that, it is sort of a test, the agency knows what the answers should be, they are sending samples to the laboratory and the laboratory in general is aware that these are proficiency test samples, does the analysis, reports the results back to the agency and then the agency, which may also send these tests out to many other laboratories, will compile the results and send a report out.
MR. CLARKE: What is the purpose of proficiency testing?
DR. COTTON: It is to enable you to make an unbiased judgment about how your lab--how well your laboratory is performing, because you have an opportunity to do a set of samples where someone else knows what the answer should be and also to compare how you did with how other laboratories receiving equivalent samples would do or did.
MR. CLARKE: Incidentally, is cellmark, and you described yesterday cellmark in the United Kingdom, is it involved in providing proficiency samples to any laboratories?
DR. COTTON: Cellmark in the United Kingdom has a proficiency test program where they do provide proficiency samples to other laboratories and we receive them and many other labs in the United States do as well.
MR. CLARKE: As far as these proficiency tests, are they taken by analysts in your laboratory?
DR. COTTON: Yes.
MR. CLARKE: Who participates in taking those tests?
DR. COTTON: Everyone that is involved in doing any kind of analysis for forensic or paternity case work takes proficiency tests during the year and generally each analyst is required to perform two per year.
MR. CLARKE: Does that include yourself?
DR. COTTON: It includes myself and the other Ph.D. staff, since we are involved in the analysis of the case work results.
MR. CLARKE: You touched briefly yesterday on the fact that there are other individuals in the laboratory who perform the actual bench work; is that right?
DR. COTTON: That's right.
MR. CLARKE: Would actually be pouring in the reagent, manipulating the steps necessary in the tests and then ultimately producing the product that is eventually read and interpreted?
DR. COTTON: That's right.
MR. CLARKE: In this case, and we will return to it a little bit more a little later, in this case who were those individuals who actually performed this work in this case?
DR. COTTON: The work in this case was done by Julie Cooper and Paula Yates.
MR. CLARKE: With respect to both of those individuals, have they participated in proficiency testing as well while at cellmark?
DR. COTTON: Yes.
MR. CLARKE: These proficiency tests, can you describe in a little bit more detail about how they are set up and in what form they are sent to the laboratory for purposes of testing?
DR. COTTON: I can tell you how we receive them. I don't know very much about how they are set up, since I am not involved in doing that. We generally will receive the samples. Umm, they are usually shipped at room temperature, and for forensic samples, they are made to be similar to case samples, so they are usually bloodstains and the knowns are usually bloodstains on Cotton cloth, and the evidence samples may be bloodstains or semen stains or some mixture. And generally a proficiency test will consist of three or four samples which would be the typical number of samples that might be in one case, at least that is for our laboratory, typically for a single case it will be maybe average four samples. And they are received by our quality assurance coordinator and then she hands them out to whoever is next in line to do a set of proficiency samples.
MR. CLARKE: As far as these samples, when they are sent to you and if, let's assume you are an analyst actually determining what the results from typing of these samples are, are you informed ahead of time of what the results are?
DR. COTTON: No. That is the whole point. You don't know what the results are supposed to be.
DR. COTTON: Are you therefore required to complete the test, report the result and then later you find out if you did it correctly?
DR. COTTON: That's right.
MR. CLARKE: Now, how often are these tests--and I believe you touched on this that--you have already answered this--how often are members of your laboratory required to take these tests?
DR. COTTON: Twice a year.
MR. CLARKE: Are there any organizations that set recommended frequencies for taking tests like this?
DR. COTTON: There are two organizations who have guidelines for laboratories that are engaged in DNA analysis, and both of those organizations, in regards to proficiency tests, recommend that each analyst or each person involved in case work do two tests per year at a minimum.
MR. CLARKE: What organizations are those?
DR. COTTON: One organization carries the acronym Twgdam, T-W-G-D-A-M, which stands for the technical working group on DNA analysis method and is sponsored by the FBI and consists of crime laboratories from around the United States and members of the FBI laboratory.
MR. CLARKE: Does that group also issue guidelines on a range of areas involved in DNA testing?
DR. COTTON: They have issued guidelines on conducting DNA testing, staff for DNA testing, and quality assurance programs for laboratories engaged in DNA testing.
MR. CLARKE: What was the second organization?
DR. COTTON: The second organization is Asclad lab, A-S--again it is an another acronym name. Asclad, that is the American Society of Crime Laboratory Directors, Laboratory Accreditation Board.
MR. CLARKE: If this jury had previously heard testimony about Asclad, would that be the same organization?
DR. COTTON: It would.
MR. CLARKE: When did cellmark begin taking proficiency tests?
DR. COTTON: In 1988.
MR. CLARKE: Was that shortly after the laboratory began performing case work?
DR. COTTON: (No audible response.)
MR. CLARKE: Or do you recall?
DR. COTTON: The first proficiency test that I am aware of that cellmark took was actually received in late 1987, so it would have been received about the same time, in the same time range, as we started doing case work.
MR. CLARKE: Do you, as part of the business at cellmark, compile information about how the laboratory has performed in these proficiency tests since they were begun?
DR. COTTON: Yes.
MR. CLARKE: As far as the taking of these tests, these proficiency tests, and the results, can you describe for us, beginning back when proficiency started, how the laboratory has performed?
DR. COTTON: Yes.
MR. CLARKE: All right. Would you do so.
DR. COTTON: I can. When--let me preface my remarks by a very brief explanation that proficiency tests have been available all during the time that DNA testing has been done, but early on proficiency testing specifically designed for DNA testing labs was not available and the tests were geared more towards serology analysis. In 1988, or actually late 1987, there was a proficiency test put together by the California association of crime laboratory directors which cellmark agreed to participate in. That test was not a typical proficiency test as I have just described one to you, and the reason is that that test consisted of 49 samples. There were no designated known samples and unknown samples. So what I'm really saying is that that proficiency test did not resemble a regular case in terms of the number of samples and the fact that in a normal case you have known samples and unknown samples. Apart from that, the samples were forensic type samples, stains and so forth. In that proficiency test we provided results back to the Cacld, which is the abbreviation for California Association of Crime Laboratory Directors, and we later found out that we had one error in that proficiency test, that is, we matched a sample to another sample and that match was incorrect.
MR. CLARKE: With regard to those results--incidentally, were the remainder of the results--how did you do on those?
DR. COTTON: The remainder of the matches that we got were okay. There are some samples that we didn't get any DNA from, there were some samples that we didn't get a pattern from that was usable, so I'm not implying the rest of the results were perfect, but there with no other incorrect matches in the results, other than the one.
MR. CLARKE: As far as this--this error, as you have described it, do you just take that error into account and just continue in your work or do you take any action as a result of that?
DR. COTTON: I certainly wouldn't want to just continue working without attempting to figure out what had caused such a significant error. So the procedure that I followed was the people that had worked on the test went back and examined all of their records, all of the tubes that they had kept during the analysis of that test, and they were able--and I'm saying "they"--although I was there at the time, I didn't participate directly in figuring this out--they were able to determine whether the error had occurred and what had happened to cause that error and that was helpful then in making some changes in our procedure to improve the procedure.
MR. CLARKE: In what way?
DR. COTTON: Well, there were some changes made in--made to address the error. You sort of have to know what the error was for to it make a lot of sense, but there were changes in how the tubes were labeled so that--because part of the problem was that--an analyst couldn't read the labels well on the tube, and there was also a piece of equipment purchased to help us avoid the situation that had caused the error.
MR. CLARKE: All right. In terms of proficiency tests taken after that time, can you describe the performance of the laboratory.
DR. COTTON: We are going to work up in years here, I assume?
MR. CLARKE: Okay.
DR. COTTON: So then comes along 1989. Now, actually without the document in front of me, there probably--there may have been a few other tests in 1988, besides this large one, and as far as those tests went, there was nothing wrong with Cellmark's performance. In 1989 there were tests taken and for the most part there was no problems with Cellmark's results, but in 1989 we again accepted a sample sent from CACLD. This sample set consisted of 50 samples, was designed the same way the first one was and cellmark had an additional error in 1989, an incorrect match in that 50-sample set.
MR. CLARKE: As a result of that error, was any further review undertaken or was this again a situation--not again, but was this a situation in which you just continued on with case work?
DR. COTTON: As a result of that error additional review was undertaken. It took quite a long time to do that review because there was a lot of material to look at. The error--the specific error was not able to be determined. We could narrow it down to a particular two samples between which the error had occurred and we knew the step at which the error had occurred, but exactly how it occurred we can't tell--I can't tell you and I was part of this analysis. To--we went in and looked at our procedure and the adjustment that we made to our procedure as a result of this test was one that I've already talked about, and that was the mandate in the procedure that you do not do the DNA extraction for evidence and known sample at the same time in the same place. That is, you do the evidence, you put that away, and then you do the known samples, because the most--and so this was a situation where DNA from one sample had contaminated another, and obviously the most critical contamination that you could have would be from a known sample to an evidence sample. And so to avoid that, those samples are not extracted at the same time and that was the adjustment that we made in our procedure as a result of that error in 1989.
MR. CLARKE: Are changes or improvements in procedure one of the goals of proficiency testing or one of the benefits?
DR. COTTON: Well, they are one of the benefits. It does give you a window on your work that you wouldn't have if you weren't taking proficiency testing.
MR. CLARKE: That was 1989; is that right?
DR. COTTON: That's right. Now, again, there would have been some other proficiency tests taken during 1989 that would be similar to the ones--the typical ones that I described before where you get three or four samples, and there were no false matches or false exclusions in any of the other tests in 1989.
MR. CLARKE: All right. What about 1990?
DR. COTTON: From 1990 to the present time we have continued to take proficiency tests. They are all now--in fact, the proficiency tests are much better now than they were back then because they are designed for DNA analysis laboratories specifically, and as I said, they generally consist of three or four samples, and since this time there have been no further errors in proficiency tests in terms of incorrect matches or incorrect exclusions in our proficiency testing.
MR. CLARKE: During that time period from 1990 through 1995, approximately how many different tests are we talking about? Can you estimate that?
DR. COTTON: You know, that is all listed in a document that I know you have and I have a copy of, but it is not down here with me. Let's estimate it this way: We have had for the most part, during these years, six or seven analysts and they have taken at least two tests per year, occasionally more than that. So you are doing about, say, fourteen tests per year at a minimum.
MR. CLARKE: Would then one add also onto that the three Ph.D's who also perform these tests?
DR. COTTON: We don't get a separate test, because the design of the test is that you do it as if it was a regular case, so we are participating in the test in our normal role for doing case work, so we don't get additional tests that are directed just toward us.
MR. CLARKE: All right. As far as licenses, does cellmark hold any licenses?
DR. COTTON: Yes, we do.
MR. CLARKE: Can you describe those, please?
DR. COTTON: Well, we hold a license to handle radioactivity. We hold a license to transport--it is a clinical laboratory--under the clinical laboratory improvement act, to--basically that allows us to transport samples across state lines and there is an inspection associated with that license. We have a license in the State of Maryland to do molecular biology techniques. There is an inspection associated with that license. Umm, we have a few other odd licenses that aren't very well--
MR. CLARKE: Is there any certification or accreditation process involving DNA testing laboratories in this case?
DR. COTTON: Yes, there is.
MR. CLARKE: Can you tell us about that, please.
DR. COTTON: There are actually three programs of which we participate in two. One of them is sponsored by the American association of blood banks, and I mentioned that I think yesterday, and it is an accreditation for doing paternity testing and you can get accredited using--for like HLA testing or ABO testing. Since we only do DNA testing, our accreditation is in that area only.
MR. CLARKE: Of paternity testing?
DR. COTTON: Yes, that is doing paternity testing using DNA analysis.
MR. CLARKE: Through the American association of blood banks?
DR. COTTON: That's right.
MR. CLARKE: Are there any other organizations who participate in accrediting or certifying DNA laboratories?
DR. COTTON: There is another organization that is--accredits laboratories for paternity testing and it is a very similar program to that of the American association of blood banks and we aren't currently participating that program. And there is a program sponsored by Asclad that is the American society of crime laboratory directors, for accreditation of forensic laboratories doing DNA analysis and we--
MR. CLARKE: And I'm sorry?
DR. COTTON: We hold an accreditation from that organization.
MR. CLARKE: I'm sorry, did you say you have been accredited by Asclad?
DR. COTTON: Yes, we have.
MR. CLARKE: As far as that accreditation, to your knowledge were you the first private laboratory accredited by Asclad?
DR. COTTON: Yes. We--there had been many--or I don't know about many, but 20 some DNA laboratories accredited by Asclad and these were all state labs or local labs or some type of government lab. So we were the first private for business laboratory that Asclad accredited.
MR. CLARKE: Now, in that process of accreditation by the American society of crime laboratory directors, what did that entail? What did it take to obtain that?
DR. COTTON: It was preparation. Involved about six months of work off and on. We submitted to them answers to a very long questionnaire. We submitted documentation of our procedures for quality assurance. We submitted documentation of our testing procedures in the laboratory. And I don't know, we submitted--you know, it is one of those things where you send in three copies and stuff like that. And then we were given an inspection date and we had an inspection from Asclad inspectors. We had three inspectors in our laboratory for three days, and they looked at individual cases, they looked at the laboratory facility, they interviewed all of the laboratory staff involved in forensic cases, and then they did an evaluation.
MR. CLARKE: And as a result of that evaluation what happened?
DR. COTTON: As a result of that evaluation we received an accreditation by that organization this past September.
MR. CLARKE: As far as this accreditation process, did it include, for instance, the laboratory's use of RFLP typing in forensic cases?
DR. COTTON: Yes, it did.
MR. CLARKE: Did it also include your laboratory's use of PCR in forensic cases?
DR. COTTON: Yes, it did.
MR. CLARKE: You've also mentioned an organization that you have described as Twgdam or Twgdam. Does that organization--and I believe you mentioned earlier--does that organization produce guidelines for DNA typing in forensic cases?
DR. COTTON: It does.
MR. CLARKE: Can you tell us a little bit--you described some basic areas that those guidelines describe. Can you tell us in a little bit more detail how this covers forensic DNA typing?
DR. COTTON: It is--it is very similar, although not identical, to the guidelines that you have to meet for Asclad. The guidelines cover what kind of education and training your staff should have, what kind of quality assurance program you should have, what kind of documentation of the work that you do that you should keep. There are some specifications in there about how the DNA testing should be done, guidelines on general aspects of doing the DNA testing, and there are some guidelines as to how the results should be reported. There is then a separate document written by the same organization that covers in more detail what would be--what a good quality assurance program would encompass.
MR. CLARKE: As far as these guidelines from Twgdam, does cellmark follow those guidelines in its forensic case work?
DR. COTTON: Yes, we do.
MR. CLARKE: Incidentally, I know you described Twgdam as being sponsored by the FBI; is that right?
DR. COTTON: It is made up of a lot of crime labs and my understanding is that it is sponsored by the FBI. I don't--we are not a participant--we are not a participant in Twgdam so you know, I'm not positive that that is correct.
MR. CLARKE: In terms of your human identification or forensic case work at cellmark, are you asked to perform testing exclusively by Prosecuting agencies?
DR. COTTON: No.
MR. CLARKE: Who else asks you to perform case work?
DR. COTTON: We may be asked to do case work by Defense--a Defense attorney, and in terms of Prosecuting agencies, I guess you are including both investigators and attorneys, so we--we work for whoever is interested in sending us a case.
MR. CLARKE: In other words, by your last answer, you were referring to being asked to perform testing by a Prosecutor's office like the Los Angeles District Attorney's office in this case?
DR. COTTON: Yes. We might receive samples from a District Attorney's office. We might receive samples sent to us by a crime lab or we might receive samples from an investigator.
MR. CLARKE: Far as your testing, is it the case that in some instances you obtain test results and after that criminal charges are filed in cases?
DR. COTTON: Yes, that happens sometimes.
MR. CLARKE: Is it also the case that following your testing in case work it may be that criminal charges already filed are dismissed?
DR. COTTON: Yes, absolutely.
MR. CLARKE: Is it also the case that after obtaining results in your case work that in fact people may be released from prison as a result of those case work results?
MR. NEUFELD: May we have one moment, your Honor, just so I can speak to counsel?
(Discussion held off the record between Deputy District Attorney and Defense counsel.)
MR. NEUFELD: Thank you.
THE COURT: Proceed.
MR. CLARKE: Thank you, your Honor. And lastly, Dr. Cotton, has your laboratory retained results in cases that may lead to exonerations, that is, charges actually being dismissed?
DR. COTTON: Yes.
MR. CLARKE: Now, as far as the laboratory itself, do you allow individuals not a part of the laboratory to visit your laboratory?
DR. COTTON: Yes.
MR. CLARKE: And what can that include?
DR. COTTON: It--there is two general groups of folks that that might include. We might be asked to have a--suppose we are doing a case for the Prosecution. We might be asked that a Defense expert, that is, a scientist working with the Defense, to be allowed to come and view the testing while it is being done, and we do allow that. We have a set of guidelines that everybody needs to--we feel that everybody needs to agree to, and if everybody agrees to those guidelines, an expert for the Defense is allowed into the lab to watch testing. And we may have the reverse situation. We may have a case that has been done for either the Prosecution or the Defense and another expert working for that same group may wish to come--who may then come to Court to say, yes, I think this testing is okay, or no, I don't, but usually it is yes, I do think it is okay. That expert may come to the lab, look at the laboratory, discuss laboratory procedures, ask laboratory staff questions or something to become familiar with how work is done in our lab.
MR. CLARKE: Now, you described the fact that there are some guidelines in place about these visits?
DR. COTTON: Yes, there are.
MR. CLARKE: What do they include?
DR. COTTON: Umm, as far as watching testing, the most important thing that they include is that the visitor will only be allowed in the laboratory when testing on that specific case is ongoing and that is there are many times during the testing where you do something and then you have to wait maybe four hours before you can do the next thing, so that the visitor isn't allowed in the lab during that four-hour waiting period, they are asked to wait somewhere else. And the other really important criteria is that they are not allowed to ask questions of the analyst or talk to the analyst while the analyst is working, and that is really to make sure that the analyst is allowed to give their full attention to the samples that are in front of them and they are not distracted by somebody saying "why are you doing that" or "what step is this" or something like that.
MR. CLARKE: All right. With regard to these visits, how common are they in cases?
DR. COTTON: They are not enormously common. We probably have Defense experts in three or four times a year maybe, probably not more than that.
MR. CLARKE: So on the average once every few months?
DR. COTTON: Yes.
MR. CLARKE: All right. With regard to this case, did any such visit occur?
DR. COTTON: Yes.
MR. CLARKE: Could you describe that, please.
DR. COTTON: There were two visits. The first was a visit from Dr. Edward Blake and Dr. Henry Lee, and they came to the lab and--and witnessed and took part in, actually, the division of some of the samples. The samples were small blood-stained swatches. Ten percent of those samples was to be set aside for future testing, and Dr. Blake actually took the cuttings that were set aside for future tests.
MR. CLARKE: All right.
DR. COTTON: That was actually an exception to our guidelines because normally we won't let--
MR. NEUFELD: Objection, your Honor. Just a point of clarification.
THE COURT: Side bar with the Court reporter, please.
MR. NEUFELD: Yes.
(The following proceedings were held at the bench:)
THE COURT: Over at the side bar.
MR. NEUFELD: Fewer side bars here in the history of the trial and I want that to be on the record.
THE COURT: Noted.
MR. NEUFELD: Just a clarification. She said that Dr. Blake took the ten percent cuttings. He made the ten percent cuttings but the samples were left there and it was almost--I don't think it was deliberate, but the way--
THE COURT: Why don't you keep your voice down.
MR. NEUFELD: The way she said it made it sound like he took the ten percent with them, and we all know what Dr. Brake did was actually make a cut and everything was left at cellmark and maybe you can clear that up.
MR. CLARKE: I plan on clarifying that, but not immediately.
MR. NEUFELD: Right now.
THE COURT: Why don't you clear it up right now.
MR. NEUFELD: Okay. Thank you.
MR. NEUFELD: Also, as an anticipatory matter, I don't believe that Mr. Clarke can ask whether they had--whether the Defense had the opportunity to stay longer. I think that the witness can only testify as to what the Defense actually did. I don't--
THE COURT: We are not there yet.
MR. CLARKE: Right.
MR. NEUFELD: No, no, no, no, no, no. To elicit from this witness that the Defense was invited to watch the entire testing procedure and declined is not something that can be elicited from this witness. All that can be elicited from this witness is what the Defense actually did do while at cellmark.
THE COURT: I don't know that.
MR. CLARKE: I don't think we are there yet.
THE COURT: Okay. All right.
(The following proceedings were held in open Court:)
THE COURT: All right. Thank you, counsel. Ladies and gentlemen, we are going to take our 15-minute recess for the afternoon session. Please remember all my admonitions to you. And we will see you back here at 25 minutes until 3:00.
(Recess.)
(The following proceedings were held in open Court, out of the presence of the jury:)
THE COURT: All right. Back on the record. Counsel, did we get our light box set up? I understand we had a light box coming. Okay. I guess not. All right. Let's have the jurors, please.
(The following proceedings were held in open Court, in the presence of the jury:)
THE COURT: Thank you, ladies and gentlemen. Please be seated. Dr. Cotton, would you resume the witness stand, please. The record should reflect we've been rejoined by all the members of our jury panel. Dr. Cotton is again on the witness stand undergoing direct examination by Mr. Clarke. Mr. Clarke, you may continue.
MR. CLARKE: Thank you, your Honor.
MR. CLARKE: Dr. Cotton, I believe we left off and you had described a first visit made by experts from the Defense in this case?
DR. COTTON: Yes.
MR. CLARKE: And you had described the fact that Dr. Blake was present?
DR. COTTON: Yes.
MR. CLARKE: You also described the fact that he in fact actually performed some cutting of some samples at that time?
DR. COTTON: That's right.
MR. CLARKE: All right. I would like to return to that in a little more detail later. But as far as these cuttings, was his role limited, as far as the cuttings are concerned, to actually physically cutting a portion of those pieces of evidence?
DR. COTTON: That's right.
MR. CLARKE: And did those--the entire evidence including both sides of the cuttings so to speak remain in your custody?
DR. COTTON: Yes. All of the pieces remained in the custody of cellmark.
MR. CLARKE: On that occasion--and do you recall approximately when that visit was?
DR. COTTON: Well, I think it was sometime in July of last year.
MR. CLARKE: Was there anyone else present with Dr. Blake?
DR. COTTON: Dr. Lee and Mr. Neufeld.
MR. CLARKE: And is that Dr. Henry Lee?
DR. COTTON: Yes.
MR. CLARKE: Now, were there any other visits to your laboratory by the Defense in this case?
DR. COTTON: Yes.
MR. CLARKE: When did that occur?
DR. COTTON: Oh, gosh--
MR. CLARKE: Approximately?
DR. COTTON: I haven't a clue without going to look it up. I'm sorry.
MR. CLARKE: Okay. Is that something that you could look up during the break for tomorrow?
DR. COTTON: I could look it up before tomorrow.
MR. CLARKE: All right.
THE COURT: I take it that means we're not going to finish today.
MR. CLARKE: I am not confident in finishing today, your Honor. I'm sorry.
THE COURT: Let's move along.
MR. SCHECK: January 26th.
MR. CLARKE: Without getting into the date, Dr. Cotton, do you recall who was present during that visit, who actually made the visit?
DR. COTTON: Yes. Dr. John Gerdes came to visit the laboratory.
MR. CLARKE: And this was an individual also working for the Defense at that time?
DR. COTTON: That's correct.
MR. CLARKE: What was the nature of that visit?
DR. COTTON: He came to the laboratory to basically look at the laboratory layout. We did that during the visit and he was--the mission was to examine documents that we hold at cellmark that he or the Defense wished that he look at.
MR. CLARKE: Had he ever visited your laboratory before?
DR. COTTON: No, he had not.
MR. CLARKE: All right. With respect to the types of cases your laboratory takes, you described the fact that they involve human identification or forensic casework?
DR. COTTON: That's right.
MR. CLARKE: Paternity testing as well?
DR. COTTON: That's right.
THE COURT: I think that's about the sixth time we've asked that question.
MR. CLARKE: As far as other cases, does your laboratory have any contracts or have you had any contracts with the federal government?
DR. COTTON: We had a contract with the Department of Defense. I don't know that that--the contract is not still working. I don't know what the right term for that is, but it's done. And the contract was for doing analysis for desert storm casualties.
MR. CLARKE: So that was to help identify remains from the Persian Gulf war?
DR. COTTON: Yes.
MR. CLARKE: Now, approximately how many cases does your laboratory perform work on in the course of a year?
DR. COTTON: Usually between 4- and 500.
MR. CLARKE: And is that split up in any manner, paternity cases versus forensic cases?
DR. COTTON: Oh, I'm sorry. That 4- to 500 would be forensic cases only and the paternity cases would be, oh, somewhere between a thousand and 1500.
MR. CLARKE: You brought up the term earlier today "quality assurance." What is that?
DR. COTTON: Basically, it's the set of procedures that are worked alongside your normal work to make sure that the equipment is functioning and to ensure that the quality of the work that comes out of the laboratory is always high.
MR. CLARKE: Do you actually have a person who's assigned this area of quality assurance?
DR. COTTON: Yes, we do.
MR. CLARKE: And what's that person's role? What does he or she do?
DR. COTTON: Umm, she keeps--well, she does a whole lot of different things. She--it might be a little easier just to sort of say what happens in a quality assurance program.
MR. CLARKE: All right.
DR. COTTON: But, for example, it includes being able to track and when reagents are made. That is things come into the lab and they're used to make solutions. So there are records of those solutions. There are many different things in the labs that have to be at constant temperature. So all the refrigerators, freezers water baths and so on, all those temperatures are maintained. She's also responsible for administering and looking at proficiency tests. She does audits of the laboratory. That is, every month or two months, she will walk through the laboratory unannounced and check out to make sure that all the equipment is in order. Anything that should have been calibrated or adjusted on a routine basis, the records are in place that those calibrations or adjustments have been done. And I guess that's the general idea of what she does. And now I don't remember where I was supposed to go from there.
MR. CLARKE: Just in terms of quality assurance, this person performs this function of overseeing, quality assurance as you described it?
DR. COTTON: She oversees--yes. She oversees it. That doesn't mean she goes and does all the temperature checks, but she oversees the entire program.
THE COURT: Dr. Cotton, if you would, would you allow Mr. Clarke to finish asking the question before you start your answer?
DR. COTTON: Yes, sir.
THE COURT: You were both talking together.
MR. CLARKE: Now, as far as casework, you receive cases in the laboratory; is that right?
DR. COTTON: That's correct.
MR. CLARKE: What steps do you take to ensure that when you receive, for instance, a set of evidence samples and let's say one or two known samples, to ensure that the chain of custody or the integrity of that evidence remains proper?
DR. COTTON: The samples are assigned to a specific analyst. The analyst logs in each of the samples on a form. That means he or she writes down a specific description of the items that are received, how they were received, from whom they were received. We usually get a letter with the samples that says who we are allowed to contact regarding results, who we're going to send the bill to and so on. The analyst has specific areas within a locked evidence room where he or she stores the materials. The analyst has custody of the materials the entire time they're at cellmark and during the testing, keeps detailed records of where the samples are, at what stage in the testing. That is, she doesn't write down where they are because they would be in her area of the refrigerator or freezer, but she or he would write down they're in the freezer, they're in the refrigerator if that was important to keep track. And there are a lot of forms that get filled out during the testing that document how the testing was performed, and then at the end of the testing after the report is written, that person then returns the evidence or anything remaining from the evidence to the submitter.
MR. CLARKE: You've described earlier that two individuals who actually performed testing in this case were Julie Cooper and--I'm sorry. Did you mention the second individual?
DR. COTTON: I did. Paula Yates.
MR. CLARKE: Paula Yates. Is there a title that they have in the laboratory?
DR. COTTON: Both Julie and Paula are senior molecular biologists.
MR. CLARKE: Why were there two individuals performing the actual testing in this case?
DR. COTTON: Julie originally received the samples in this case, and sometime after she started the samples, she accepted a job at the Maryland State DNA laboratory where she's now a supervisor. And so because she was leaving cellmark, she transferred custody of all of the materials at that time to Paula Yates who continued on with the testing until it was completed.
MR. CLARKE: Are you familiar with the qualifications of both Julie Cooper and Paula Yates?
DR. COTTON: Yes.
MR. CLARKE: Can you briefly describe each of their qualifications at the time of their testing?
DR. COTTON: Both of them had worked for cellmark for about six years. Paula is the supervisor of the forensic group, has a bachelor of science degree from the university of Maryland and about six years experience of doing forensic testing. Julie has a masters degree in forensic science from George Washington university. She also had about six years of experience in forensic testing.
MR. CLARKE: Had you prior to this case previously worked with both of those individuals, Julie Cooper and Paula Yates?
DR. COTTON: Yes. Many times.
MR. CLARKE: And is that something--well, let me rephrase that. Did you in fact work with them on a number of cases prior to this case?
DR. COTTON: Yes.
MR. CLARKE: Have you had an opportunity to review their casework in previous cases as well?
DR. COTTON: Yes.
MR. CLARKE: As far as the testing techniques that are used in the laboratory, do you have in place protocols about how tests are to be conducted?
DR. COTTON: Yes, we do.
MR. CLARKE: First of all, what is a protocol?
DR. COTTON: Basically, it's sort of like a recipe book. It lists all the steps on how to do the test in--in a lot of detail.
MR. CLARKE: Do these protocols apply to both your RFLP typing as well as your PCR typing?
DR. COTTON: Yes. There's a separate probe--there's one book basically for RFLP and another book for PCR testing.
MR. CLARKE: Is it common in science to have protocols describing how to conduct scientific tests?
DR. COTTON: Very common.
MR. CLARKE: As far as these protocols, is it something--for instance, for either RFLP typing or PCR base typing--that is relatively short or is it detailed and extensive?
DR. COTTON: I've seen protocols that are relatively short and I've seen them that are detailed and extensive, and ours happens to be detailed and extensive.
MR. CLARKE: Do you have any role in, for instance, either the creation or changes that are made to these written protocols?
DR. COTTON: Yes.
MR. CLARKE: Can you describe that, please?
DR. COTTON: As laboratory director, my signature is required for final approval for any change in the procedure and my signature is required yearly on the procedure as evidence of the yearly review. So I participate in that yearly review with the quality assurance coordinator, and if we decide to make a change or an addition to the protocol, someone else certainly might write that and many people may look at it, but it requires my signature as laboratory director to be put into place.
MR. CLARKE: I gather then changes are made to the protocol?
DR. COTTON: Frequently.
MR. CLARKE: Why is that?
DR. COTTON: Umm, many of the changes are simply additions. That is, we might add--for example, we were doing DQ-alpha and then we wanted to do the poly-marker testing. So we had to write protocol that now included the poly-marker testing. But the other thing is that you might go to a scientific meeting or read something in the literature where someone had discussed a procedure that gave very good results. You would then check that out in your laboratory, and then if it was getting better results than your current procedure, you would go ahead and change your protocol to reflect the improvement.
MR. CLARKE: Is that the nature of science itself?
DR. COTTON: Yes.
MR. CLARKE: As far as these protocols, do they start at a particular portion of the testing process and end at another one? Does that question make any sense?
DR. COTTON: Well, it just covers all the steps.
MR. CLARKE: Okay. From what point to what point?
DR. COTTON: From--it starts out how do you log in the evidence. How do you properly receive the evidence is where it starts.
MR. CLARKE: And then where does it end?
DR. COTTON: It ends in how do you interpret the results.
MR. CLARKE: Are individuals who are working in the laboratory such as Julie Cooper and Paula Yates required to follow these protocols?
DR. COTTON: Yes.
MR. CLARKE: What happens when something comes up in the course of testing?
THE COURT: Kind of vague, isn't it?
MR. CLARKE: Yes, it was. Perhaps if I added a little more to it.
MR. CLARKE: What happens if something comes up in the course of testing that isn't covered by the protocols? What happens?
DR. COTTON: Umm, generally, first you would make some notations about that in the case notes and then you might consult with someone else. If there's something--if we think that something should be done that's unusual, that's outside the protocol, then we'll make notations about that, and that generally would require approval of one of the Ph.D. staff.
MR. CLARKE: Were your protocols reviewed by the Asclad inspection team prior your receiving their accreditation?
DR. COTTON: Yes, they were.
MR. CLARKE: Now, you've described the fact that records are kept in the course of receiving evidence through the various testing processes; is that right?
DR. COTTON: That's right.
MR. CLARKE: And are you familiar with how those records are kept by the analysts themselves?
DR. COTTON: Yes, I am.
MR. CLARKE: What's the basis--how come you're familiar with how they're done?
DR. COTTON: Well, my role in the case is to get all the records and including the results and a draft report and review the records, review the data and review the report and participate in signing that report with the person who actually did the work with their own hands. So as part of my every-day job, I'm going through case records, reading them, checking them, making sure that they're all in order so that I can sign the case when it's done.
MR. CLARKE: To be able to describe results in a given case, how can you do that without actually sitting there and watching every step of the testing process?
DR. COTTON: When you're done with the test, you have some data. You have some information. So what I'm doing is participating with the analyst in interpretation of that data. And I have not sat and watched--I mean, if I was going to sit and watch, I might as well do it myself. I have not sat and watched every step of the test.
MR. CLARKE: As far as your ability to offer an opinion, do you review all of the material in a given case prior to offering any opinions about it?
DR. COTTON: Yes.
MR. CLARKE: Whether that's in the form of testimony or in a written report.
DR. COTTON: In either case, I would be reviewing all of the data and most of the documentation in the folder.
MR. CLARKE: Okay. I'd like to turn your attention to an area that's commonly referred to as population frequencies. Is that term familiar to you?
DR. COTTON: Yes, it is.
MR. CLARKE: All right. What is that?
DR. COTTON: It's the expression of saying for a particular genetic characteristic within a population or large group of people how often would you expect to find that characteristic.
MR. CLARKE: For instance, would population frequencies enter into a description of approximately how many people have the ABO type, blood group type O for instance?
DR. COTTON: Yes.
MR. CLARKE: As far as population frequencies, could you describe, please, the education and training you received in the area of frequencies?
DR. COTTON: The--my exposure to this particular area of biology has mainly been in the seven years I've been at cellmark because we deal with defining frequencies for the genetic markers we use every day. So I have no specific training outside of cellmark. We have a person on our staff who has a Ph.D. in this particular area. And as a part of my job, I--and when I go to scientific meetings, I'm both hearing lectures in this area and I make it a point to read the literature in this area as well.
MR. CLARKE: How about your experience with frequencies in, for instance, casework?
DR. COTTON: Well, in terms of doing a case, if you have samples that are consistent with some known person and this is part of your report, then as part of your report, if there is sufficient data, you're saying how often you might see this particular set of genetic characteristics. So in all the report--not all, but many of the reports that go out involve the calculation of frequencies or particular sets of genetic characteristics.
MR. CLARKE: Do you consult with experts in the area of--well, let me rephrase that question. Is there a particular area of science that deals with, in particular, the area of populations and frequencies of genetic marker characteristics?
DR. COTTON: Yes, there is.
MR. CLARKE: What's that called?
DR. COTTON: That discipline would be referred to as population genetics.
MR. CLARKE: Do you and have you as a result of your employment at cellmark since--I'm sorry--what year?
DR. COTTON: 1988.
MR. CLARKE: Have you consulted with population genetics experts about this area of population frequencies?
DR. COTTON: Yes, we have.
MR. CLARKE: And I believe you mentioned that you had an individual in your laboratory who--whose field of specialty is population genetics?
DR. COTTON: Yes. One of our Ph.D. staff, Dr. Lisa foreman, is a population geneticist.
MR. CLARKE: Do you routinely consult with her about population frequency information?
DR. COTTON: Certainly.
MR. CLARKE: As far as work conducted in your laboratory, do you then use population frequency data as a means of describing the significance of your results?
DR. COTTON: Yes.
MR. CLARKE: To your knowledge, has population frequency data been used for a substantial period of time?
DR. COTTON: Oh, yes.
MR. CLARKE: Can you tell us a little bit about that?
DR. COTTON: Well, it's certainly been used in DNA typing since laboratories were initially engaged in that. But in terms of formulating information about serological results, the same kinds of calculations and information is usually provided. So if you have a set of information, then it includes blood types and PGM or however many markers you've done, you can do a calculation to say this particular set of markers would occur in some percentage of a particular population.
MR. CLARKE: Is that related to, is it similar, different from population frequency use in DNA typing?
MR. NEUFELD: Your Honor, I would object and I would ask that I conduct very brief voir dire on her expertise in this particular area.
THE COURT: Overruled. We're still establishing that at this point.
MR. NEUFELD: Okay.
THE COURT: Proceed.
MR. CLARKE: Do you recall the question?
DR. COTTON: Could you go--ask it again?
MR. CLARKE: Actually, your Honor, would it be possible to have that reread because I can't recall it exactly.
THE COURT: It related--
MR. CLARKE: Actually I can. I'm sorry.
MR. CLARKE: As far as this use of population frequency data, has it been in use for a substantial period of time?
DR. COTTON: Yes.
MR. NEUFELD: Objection, your Honor. Foundation.
THE COURT: Overruled.
MR. CLARKE: As far as its use, that is, the use of population frequencies in casework, when did you begin using population frequency data in terms of reporting it in actual cases?
DR. COTTON: You're talking about me personally or cellmark in general?
MR. CLARKE: Let's start with the laboratory.
DR. COTTON: Okay. There's going to be a little bit of time--there's a time frame in here where I can't be particularly accurate about the answer. I came to cellmark in 1988, and sometime during that year, I started being involved in forensic casework. At the time that I started being involved in forensic casework, we were in the process of developing population data that would allow us to do that. I think that we were all providing some frequencies before that based on population data from the other cellmark laboratory, but I'm not absolutely certain.
MR. CLARKE: What about you personally?
DR. COTTON: The point at which I would have been--become involved would have been the point at which I began signing forensic casework, and I was also involved in setting up how the population samples at cellmark would be analyzed and reported. So at that point, I became involved in discussing, understanding and generating population frequencies as they relate to DNA typing.
MR. CLARKE: Do you have any role in supervising the actual reporting of frequencies in your laboratory, that is in casework?
DR. COTTON: In terms of signing a particular case, both people who are signing that case have a role in generating and reporting that information. So in my role in signing cases, I am responsible for the information that's generated for that particular case and I also have overall responsibility for the scientific information that comes out of the laboratory. So under that umbrella, I guess I would have some responsibility as well.
MR. CLARKE: As far as your previous testimony as an expert in DNA typing, have you reported population frequencies during that testimony?
DR. COTTON: Yes, I have.
MR. CLARKE: And I'm sorry. How many times had you said approximately you've testified previously?
DR. COTTON: Oh, probably about 90 times.
MR. CLARKE: And amongst that 90, is there any way you can put a figure or a rough estimate of the percentage of the time you report population frequency data?
DR. COTTON: I couldn't give you an exact figure since I'm not even giving you an exact figure of how many times I testified. But for most of the cases, probably 80 or 90 percent of the cases in which testimony is provided in Court, we are providing some population genetic frequency for a particular set of markers.
MR. CLARKE: The written protocols you have in place in the laboratory, do they describe the reporting of population frequencies?
DR. COTTON: Yes, they do.
MR. CLARKE: And in what manner? Is this--is it fairly short, detailed? Can you describe that?
DR. COTTON: The calculations, although they're done by computer, can also be done by hand, and the protocol simply describes how to go about entering that data for--and that's for RFLP. For PCR results, we do not have a computer program to do the calculations for us. So the calculations are done by hand. And when you review a case, in my role in reviewing a case, those calculations have been done by the analyst, I'm checking them and then we're both signing the report.
MR. CLARKE: When you say that those are done by hand, do you mean by using a calculator or really by hand?
DR. COTTON: No. I mean by writing the individual frequencies down so that they--we have a permanent record of them and then by using a calculator, to multiply them together.
MR. CLARKE: All right. With regard to this concept of population frequencies, how do you calculate them for a given type, for instance, at a given genetic marker?
MR. NEUFELD: Objection at this point. Foundation, your Honor.
THE COURT: Sustained.
MR. CLARKE: With regard to this area of population frequencies, is there a term called "database"?
DR. COTTON: Yes.
MR. CLARKE: What's a database?
DR. COTTON: It's basically a sample of a population. If you--obviously, you can't sample all the people in the country or you couldn't even sample all the people in a given state. So you need to take a small subset of the total population and then regard that as your sample. It's similar to taking a poll for television viewing. Nobody calls up everybody who's watched television on a particular night. They take a sample of the people who have watched television on a particular night and make some assessment of the larger sample based on the small--the larger population based on the small sample.
MR. CLARKE: And how does that play a role in your ability to be able to estimate how common or how rare a set of characteristics is?
DR. COTTON: Well, I think you've just actually said the important word. That is "estimate." If I have a sample of 200 individuals, for example, and I do an RFLP test on all those 200 individuals, I've now looked at--for any given genetic locus, I've looked at 400 chromosomes. So I have 400 pieces of information. And from that, I can ask the question if I have a DNA band that's 5,000 base pairs long for this particular genetic locus, how often in my population sample do I find a person with this genetic characteristic, a DNA band at 5,000 base pairs.
MR. CLARKE: Does that involve then the use of more than one database for a particular genetic marker?
DR. COTTON: Traditionally, databases are divided into racial or ethnic groups.
MR. NEUFELD: I'm sorry. Objection again. Foundation rather than traditional.
THE COURT: Overruled.
MR. CLARKE: You may continue.
DR. COTTON: Our databases at cellmark are divided into racial or ethnic groups. You could maintain any number of databases in our laboratory. We have three. They are popu-- and I guess for the moment, I'll just speak about RFLP. But the situation for PCR is similar, and they are divided into African Americans, Caucasians and Hispanics.
MR. CLARKE: Why this concern with different databases from different racial or ethnic groups?
MR. NEUFELD: Objection. No foundation with regards to her expertise.
THE COURT: Sustained.
MR. CLARKE: With regard to the area of population frequencies, are you familiar with other DNA laboratories and their methods of calculating these estimations of the--how common or how rare characteristics are?
DR. COTTON: Yes, I am.
MR. CLARKE: How are you familiar with that?
DR. COTTON: Both from reading the literature, talking to other scientists and hearing information presented at scientific meetings.
MR. CLARKE: Is this something you do on a regular basis?
DR. COTTON: Do those things?
MR. CLARKE: Yes.
DR. COTTON: Yes.
MR. CLARKE: What about scientific literature? Does it play any role in your knowledge of the area of population frequency data?
DR. COTTON: Yes.
MR. CLARKE: Can you describe that in more detail?
DR. COTTON: Well, there's actually--at this point, there wasn't--this was not the situation in 1988 for example. But at this point, there is a lot of information in the literature about population data based on DNA typing. So anyone who is interested or involved in doing DNA typing analysis either for paternity or for forensics would be interested and need to keep up with this literature.
MR. CLARKE: What types of literature do you read in that area other than the general topics obviously? But are there particular resources that you have in terms of particular journals and so forth?
DR. COTTON: There are two journals in which--which would include most of the papers, certainly not all. One would be the journal of forensic science and the other would be the American journal of human genetics. Now, there are a few papers that are somewhere else. There's a couple in science and--anyway, they're here and there. But for the most part, the two journals have covered more of them than maybe others, some other journals.
MR. CLARKE: If you could describe, how do those journals, how closely do they deal with this actual concept of population frequencies and reporting results following DNA typing?
MR. NEUFELD: Objection. Hearsay, no foundation as to her expertise on this area.
THE COURT: Overruled. Proceed.
MR. NEUFELD: And may I voir dire the witness?
THE COURT: Overruled. Proceed.
DR. COTTON: Are you sort of asking me what types of things are in literature?
MR. CLARKE: That you read, yes, in this area, population frequencies.
THE COURT: What I'm allowing, counsel, is what is the source of her knowledge in this area.
MR. CLARKE: Yes.
THE COURT: All right. Rephrase the question.
MR. CLARKE: All right. With respect to your review of scientific literature regarding population frequencies, can you just tell us, as far as the literature you've described, does it address the reporting or the estimation of frequency data in DNA typing cases?
MR. NEUFELD: Objection.
THE COURT: Overruled.
DR. COTTON: It doesn't so much address the reporting. What the literature is addressing is how the frequencies are calculated and--and how individual frequencies are determined and how populations differ. That is, are there large or small differences between African Americans and Hispanics or Caucasians and Hispanics in how frequently these particular characteristics occur.
MR. CLARKE: Do you regularly speak with population geneticists about the methods used in your laboratory? And you've described the one on staff. Are there other individuals?
DR. COTTON: Uh, we have a particular person who's a population geneticist who we speak with on a regular basis. And that would be Dr.--
MR. NEUFELD: I'm going to object as to the "we" and need to ask for clarification as to--
THE COURT: Overruled. Proceed. There's nothing confusing about this. Proceed.
DR. COTTON: And that would be Dr. Bruce weir.
MR. CLARKE: Who is Dr. Bruce weir?
DR. COTTON: Dr. Bruce weir is the Professor at north Carolina State university. He is a population geneticist and very highly regarded in this area.
MR. CLARKE: Has he written in this area?
DR. COTTON: Yes, he has.
MR. CLARKE: A little bit or extensively?
DR. COTTON: Extensively.
MR. CLARKE: In terms of these consultations with Dr. Weir, has he reviewed material at your laboratory that you utilized to report population frequency data?
DR. COTTON: Yes, he has.
MR. CLARKE: As a result of that, have you incorporated any suggestions, comments, et cetera, that he may have about the methods of reporting data in your laboratory?
MR. NEUFELD: Objection. Hearsay as to Dr. Weir.
THE COURT: Overruled.
DR. COTTON: The basic answer to the question is yes. Most of his input is in some data that's being currently developed. He's also looked at much older data that was developed by our laboratory, but he hasn't--in the older data, he has not made any suggestions that resulted in large change or really any changes in procedure to speak of.
MR. CLARKE: And that was after his having--when you say no changes, that was after his having looked at these procedures in place in your laboratory?
DR. COTTON: Yes, that's right.
MR. CLARKE: All right. Is there a way you can describe the basic method by which population frequencies are report--are actually calculated?
DR. COTTON: Yes.
MR. CLARKE: All right. Could you do that, and would it help to use a diagram or chart?
DR. COTTON: At this--
MR. NEUFELD: Again, your Honor, I object again on foundation.
THE COURT: Overruled.
MR. CLARKE: Would it assist you to use a drawing pad or would you prefer to do it just by description?
DR. COTTON: I think we'd better have the drawing pad.
MR. CLARKE: Okay.
MR. NEUFELD: Your Honor, brief sidebar? It might save time.
THE COURT: Conclusion of the day.
(Brief pause.)
MR. CLARKE: Your Honor, I believe this would be exhibit 255, People's exhibit.
THE COURT: 255.
(Peo's 255 for id = diagram)
THE COURT: Mr. Clarke.
MR. CLARKE: Thank you. Dr. Cotton, if you would--and this will be People's exhibit 255. Do you have a title that would describe this particular chart? Population frequencies? Is that--
DR. COTTON: Population data.
MR. CLARKE: Population data? All right. Now, if you could use that diagram to demonstrate the basic method by which population frequencies are determined to describe how common or how rare a particular genetic marker type is.
MR. NEUFELD: Your Honor, I would object in so far as the general statement--
THE COURT: Sustained. Rephrase the question.
MR. CLARKE: With regard to your laboratory and how you calculate an estimate of how common or rare a characteristic is, how do you do that?
DR. COTTON: You are going to do that based on a population sample that's either been developed in your laboratory or somewhere else. In our case, our population samples for RFLP were developed in our laboratory. So if you go back to the explanation yesterday, what you're doing is, you're taking a sample of people and you're doing the RFLP test on all of those people. So what I'm going to do on the diagram is sort of show you what--give you an example of what a sample of people looks like and then show you how that would be used to estimate a frequency. So we're going a make a mini population on the diagram.
MR. CLARKE: All right.
(Brief pause.)
MR. CLARKE: Now, let me stop you if I can, Dr. Cotton. You've written on this chart labeled "population data" what appears to be the numbers 1, 2, 3, 4 and 5?
DR. COTTON: Yes.
MR. CLARKE: And then below each of those numbers, you've written in what appear to be two bands? Is that what those are intended to depict?
DR. COTTON: Right. In other words, I'm trying to show you a diagram of an autorad with five samples.
MR. CLARKE: All right. Go ahead.
DR. COTTON: Okay. In my five samples--because I have two bands for each sample. That is for each of these people, one for mother, one for father--I've got 10 bands altogether.
MR. CLARKE: Actually, would it help to draw basically lines between these lanes so that at least on this diagram--
DR. COTTON: Oh, sure.
MR. CLARKE: --it would be easier to tell? And maybe in a different color also. You can start as high as the numbers themselves that label the samples.
(Brief pause.)
MR. CLARKE: Okay. Now, if you would proceed.
DR. COTTON: Okay. Now, let's suppose that we have yet one more sample. We'll call it A. I guess I should make-- and let's say-- could I have one more color, maybe black or something?
MR. CLARKE: I hesitate to try the dry erase. Now I'm concerned it might be erasable.
THE COURT: Mrs. Robertson, do we have a black marks-a-lot? I think I have one back by my microwave. That's just a highlighter, doctor. That will fade.
MR. CLARKE: We have black. Thank you.
DR. COTTON: We'll go back to my very simple example. And let's remember that where a band is, looking from the top to the bottom, is related to how big it is. And so let's say that we've determined that this band is in sample a is 5,000 base pairs. And so the question then is, well, how often would we see another person with this particular band. And although every time you do this, you're not going to go look at a whole set of x-ray films, you have all the data in a computer from those x-ray films, and the question you're saying is, "I have a band at 5,000 here in my population sample. How many other people do I see that have a band there?" So let's say that this band was also 5,000 and this band was also 5,000 and this one was also 5,000.
MR. CLARKE: Now, when you use the term "5,000," what are you referring to?
DR. COTTON: I'm saying the length of DNA that formed this band was 5,000 base pairs long, using base pairs as a measure of length.
MR. CLARKE: All right. Go ahead.
DR. COTTON: And I've made this example very simple because I've made each of these bands be exactly the same size as this one. And that's not really necessarily--they wouldn't be necessarily that close. So out of the 10 bands that I see, three in my sample are 5,000 base pairs. So three out of 10 people, three out of 10 chromosomes would have a band at 5,000. So .3 would be the frequency for this band based on my limited sample.
MR. CLARKE: What would you do then next?
DR. COTTON: Then you would go through the same exercise for the second band in that sample. And say this was--I didn't give this any counterparts. That's not so good. I'll tell you what. Let's get rid of this one and make it be here. Suppose this size was determined to be 2,000 and this size was also 2,000. And in this case, for this band, we had one out of 10 chromosomes that had this size. So the frequency for this band would be .1. The frequency for this combination then would be two times the product, .3 times .1.
MR. CLARKE: Now, you've talked about multiplying things together there; is that right?
DR. COTTON: Yes.
MR. CLARKE: Why do you use multiplication?
MR. NEUFELD: Objection, your Honor. No foundation for this witness.
THE COURT: Sustained. Rephrase the question.
MR. CLARKE: All right. With regard to the step you just did in terms of multiplying, what's the reason for that? Why do you multiply?
MR. NEUFELD: Objection. No foundation for this witness.
THE COURT: Sustained.
MR. CLARKE: As far as--and let's talk about the databases that you have in the laboratory. You've drawn a diagram with basically five different persons' DNA on this particular chart?
DR. COTTON: Yes. On this chart.
MR. CLARKE: How large are the actual databases that you use in your laboratory?
DR. COTTON: The databases in the laboratory range in size from about a hundred and fifty to somewhat over 300. And the reason I'm saying "range" is that for one genetic locus, we may have--and for one racial group, this number of people that we've sampled may be different than for another genetic locus or another racial group. So that's the range of size--sizes of the samples that have been done in our laboratory.
MR. CLARKE: Is that enough of a number of samples to look at to be able to estimate how rare something is?
MR. NEUFELD: Objection. No foundation for this witness.
THE COURT: Sustained.
MR. CLARKE: With regard to this examination of databases--and you've used the example of what? Results of an RFLP test here?
DR. COTTON: Yes.
MR. CLARKE: How are these databases created in terms of, how do you determine out of these 150 or more samples the various sizes of the various bands?
DR. COTTON: It's done in exactly the same way the casework analysis is done. You extract the DNA. You cut it with an enzyme. You run it on a gel. You do a southern blot, you get an autoradiograph and you size the--you estimate the sizes of the bands and the autoradiograph with computer imaging system exactly as you do a regular case.
MR. CLARKE: Is this the same--this process you've described up to now--the same or different from those methods used in serological cases like methods that typed PGM four years previous?
MR. NEUFELD: Objection. No--again, foundation as to serology.
THE COURT: Overruled.
DR. COTTON: Are you asking me if the calculation is similar?
MR. CLARKE: This principal of looking at databases and determining relevant rarity or how common characteristics are.
DR. COTTON: That would be similar to how this--those calculations are done for serological markers.
MR. CLARKE: As to serological markers, once you've determine let's say an approximation of how common or rare a PGM type is, are there, using serological techniques, similar estimations made of the same sample of another genetic marker like ESD or GLO?
MR. NEUFELD: Objection. No foundation for this witness.
THE COURT: Sustained.
MR. CLARKE: To your knowledge, how similar is the method of calculating frequencies in DNA typing to previous methods that have been in use for longer periods of time?
MR. NEUFELD: Objection. Previous methods, no foundation as to this witness.
THE COURT: Sustained.
MR. CLARKE: All right. With respect to these fragments that you've described--and let's go back to the chart you've created. And you show 5,000 for what is it? Four of the particular markers and then 2,000 for two of them?
DR. COTTON: Yes.
MR. CLARKE: What role do the other fragments play that you have not at this point labeled an approximate size to as far as determining from databases how common or rare something is?
DR. COTTON: How many bands you have is how many alleles you've looked at.
MR. CLARKE: Okay.
DR. COTTON: So if you want to calculate how often you see something, it's going to be some percent of the total. So we have 10 total, three is some 30 percent of that.
MR. CLARKE: And as far as your own training in terms of reading the literature and performing these calculations in your laboratory, is what you've presented simply a simplified version of what you have reported in cases for a number of years?
DR. COTTON: Yes.
MR. CLARKE: What happens when you look at additional markers as well? In fact, let me back up. Let me rephrase that. The diagram that you've just created relates to one genetic location?
DR. COTTON: Yes.
MR. CLARKE: Do you look at more than one genetic location normally when using the RFLP technique?
DR. COTTON: Normally you would look at anywhere between three and five. Now, you could look at more. Our laboratory I should say--let me restate that. Our laboratory has the capability of looking at five.
MR. CLARKE: And do you in casework frequently use five particular locations?
DR. COTTON: Yes.
MR. CLARKE: These locations are what? A different--well, what's the technical term for the term "location"? Do you have a word that you actually use in DNA typing?
DR. COTTON: Yes. It's--it's the chromosomal locus. So the word that you'll hear is "locus." When you say, "I have a DNA probe or a genetic location," what you're really saying is the locus, which means the address on the chromosomes for this piece of DNA.
MR. CLARKE: Is there a plural form for locus when you refer to multiple locations?
DR. COTTON: Loci.
MR. CLARKE: And those are just scientific terms for where something is on the DNA molecule?
DR. COTTON: That's right.
MR. CLARKE: Okay. May I have just a moment, your Honor?
THE COURT: Certainly.
(Discussion held off the record between the Deputy District Attorneys.)
MR. CLARKE: Now, Dr. Cotton, referring to this diagram again and using the example of this one genetic marker location, in your training--and let's go back to the education you received in terms of your formal education. Did any of these concepts of population genetics arise?
DR. COTTON: Yes.
MR. CLARKE: In what way?
DR. COTTON: Well, to tell you the truth, it's been so long since I was in undergraduate school, I really couldn't tell you what course they were in. Most of the principles that are used in DNA typing that relate to population genetics, you can find a pretty good discussion for in any college genetics textbook. Now, that doesn't mean the area is simple. There are complicating things that--that when an analyst such as Bruce weir looks at a set of data, he is doing something more complicated than what's in a college genetic textbook. But the principles that are involved in doing these calculations are generally outlined at that level. That's where I would have been first exposed to them.
MR. CLARKE: Okay. And then where next in chronological order would you have then been exposed to these same concepts?
DR. COTTON: When I went to cellmark.
MR. CLARKE: And can you describe in a little more detail how you came about to be able to calculate these frequencies?
MR. NEUFELD: Objection. It's a definitive question.
THE COURT: Overruled.
DR. COTTON: Basically it was clear that we needed to be able to make an estimate for a particular genetic--for a particular DNA type or a DNA profile. It was clear that part of the information we needed to provide was how common or rare that profile would be. Umm, with assistance from the cellmark lab in the U.K. And discussions with the staff at cellmark, the group of us that were there at the time sat up the procedures that we would use, gathered the population samples, did the analysis on the samples. About the time we were doing the analysis on the population samples, Dr. Foreman came to the lab. So it was really a combined effort, certainly not mine alone, to set up the procedures that we are now using for creating estimates for population frequencies. Now, what I'm--let me make something clear. The calculations are laid out. They make some assumptions. In fact, the particular assumption that the calculation makes is that what's inherited at one genetic location does not affect what's inherited at another genetic location. These sets of assumptions are not--they're not--it's not a formula that we devise. The formula that's used in these calculations was developed in the 1930's and is the same type of formula that's used in the calculations for serological markers. What we did in the laboratory was develop the population data and then the methods to sort of query that data. And really what I'm getting at is that when I have a band that's 5,000 base pairs, there can be some variation in that size if you run the same sample over and over again. So when we query the--when we go to the database, we've never looking for something that's exactly the size. We're looking for a range of sizes. And the methodologies that we use to determine those ranges were all developed at cellmark by the group of us who were working on that project at the time.
MR. CLARKE: Now, you've described in sizing these samples just now the fact that it's an estimation; is that right?
DR. COTTON: Uh-huh. That's right.
MR. CLARKE: As part of an estimation then, when you look through databases to see if the sample matches or not--well, let me rephrase that. When you look through a database to determine approximately how rare or how common a particular characteristic is, do you take any steps to make sure that you don't overstate the rarity of that characteristic?
DR. COTTON: Yes.
MR. CLARKE: How do you do that?
DR. COTTON: The situation is that, when you run a DNA sample on an agarose gel, as I described yesterday, that procedure has limitations. You're getting an autorad, you're using a computer imaging system and you're estimating the size of the DNA that created a particular band. Even if I take the same sample and I run it 20 times or 50 times, the size estimates will not be identical. Let's go down and write underneath some--a little more realistic example.
MR. CLARKE: All right. And you're writing on the same document, People's exhibit 255?
DR. COTTON: Yes, I am. Let's say--and I'll put my new more realistic example in parenthesis. Let's say that this size came out to be 5,010 base pairs and the next one came out to be 5,030 and the one over here came out to be 4,982. None of these numbers are exactly 5,000. So in my little mini database here, if I ask the question, now assuming that the figures are the ones in parenthesis, if I said, how often do I see a person with a band at 5,000, I would look across here at these numbers and I will say, well, I hadn't seen one. So--in my 10 people, I hadn't seen anyone, and then you would have to make some assumption, well, if you look at more people, would you see one or, you know, you would have to make some calculation after that. So basically, I would very much underestimate this frequency if I look only for this exact size. But we know that there is imprecision in this gel system. It exists in every gel system that's like this that's run for RFLP typing. It's a feature of the system and it's important that if you're using this system, you understand that.
MR. CLARKE: Is that a--I'm sorry, Dr. Cotton. Is that a feature--when you say it's a limitation, is that something unique to your laboratory?
DR. COTTON: No. What I'm trying to say is that any laboratory that's doing RFLP typing and running an agarose gel will have this same problem.
MR. CLARKE: And when you say "agarose gel," that's simply what the gel is made of, agarose?
DR. COTTON: That's right.
MR. CLARKE: Okay. Go ahead.
DR. COTTON: And when I say "problem," it's not an insurmountable problem, but it's something that you want to be aware of. So if I now say, okay, I recognize that there's some imprecision in this measurement and based on some work that I've done in the laboratory, I recognize that the range of sizes that I might get might go anywhere from a low of 4,980 to a high of 5,030. Now when I go to my database, I'm not going to look just for a size that's 5,000. I'll look for something in this range because I know or I've determined in the laboratory that this is the realistic size range that I could expect if I ran something over and over and over again.
MR. CLARKE: How do you determine those ranges?
DR. COTTON: Well, you could do it in a--do it just what I said. You take a sample and you run it over and over and over again and you see how much variation you get when you do that.
MR. CLARKE: All right. Go ahead.
DR. COTTON: And we've done that and it's worked. Anyway, now when I go to the database, I'm looking at this window of sizes. And now based on that window of sizes and the numbers that I have in parenthesis, I would say I saw three people in my database whose sizes were in this range.
MR. CLARKE: Does that have the effect then of ensuring that you don't overstate the rarity of characteristics that are similar or the same?
DR. COTTON: If your window is appropriately determined, it does.
MR. CLARKE: Why do you adopt that approach in terms of frequency data calculation in your laboratory?
DR. COTTON: Because that's the logical approach. You can't--if you know the system has a limitation, you have to work around that limitation.
MR. CLARKE: Okay. You also described the existence of a formula for when you're looking at more than one genetic marker?
DR. COTTON: Yes.
MR. CLARKE: Why is that formula important when you look at more than one marker?
MR. NEUFELD: Objection as to foundation for this particular witness.
THE COURT: All right. Let me see counsel at sidebar with the Court reporter, please.
(The following proceedings were held at the bench:)
THE COURT: All right. We're at sidebar. Mr. Neufeld.
MR. NEUFELD: Okay. My concern is this. She is certainly an expert in the area of microbiology. I'm not challenging that. She's even entitled to report on frequencies for a particular allele because there's data in the laboratory, and she can testify to that as business records. But now she's being asked as an expert to testify to what methods are used to calculate a probability, a cross multiple loci. That has nothing to do with a Frye hearing. It has nothing to do with what the law is in California. It has to do with no foundation that she has the expertise to testify to what are the appropriate methods for calculating a probability of cross loci. That has to come from somebody who has either the expertise in statistics or expertise in population genetics. And no foundation has been laid that this witness has that expertise. When she testifies as an expert, she can't borrow the expertise of another witness.
And so one of the concerns I had even before, for instance, was on certain articles she had read. Although an expert can rely on hearsay and publications to help her develop her opinion, it has to be a threshold finding, that she is in fact an expert in that particular discipline. And we don't want to confuse the different disciplines here. Expertise that enables somebody to be an expert and give statistical testimony is different than the expertise that comes from being a microbiologist and testifying about genetic variation and how to do these gels and the like. And I don't believe that foundation has been laid, and that's why I object to her testifying as to the actual method for calculating the probability of cross loci.
THE COURT: Mr. Clarke.
MR. CLARKE: Your Honor, I couldn't disagree more. I have in my hand sections of five California cases that deal with the issue of qualifications at trial as far as general acceptance hearing, Frye, dealing with statistics, which is a fraction of this witness' qualifications even to talk about frequency data, and I have those if the Court would like to see them. But at this point, this witness has described her background, her training since 1988 at this point as well as the fact that she has qualified as an expert in by far the majority of her 90 cases presenting frequency data. So I think when the Court takes all this and in combination particularly with the case law in California, that this witness far exceeds the threshold needed to be able to testify as an expert on population frequency data in front of a jury.
MR. NEUFELD: Two things very briefly. One is, I believe there are instances in fact where her expertise has been rejected by a Court of law. Number two, we know that from the record in those other--in that particular--
THE COURT: Keep your voice down.
MR. NEUFELD: Certainly. In that particular discipline of population genetics. And, number two, how do know that lawyers in the other cases didn't make the same objection I'm making with the same factual record? I mean that's the problem with citing some of those other cases. The point is, I don't believe at this point in time, they've laid adequate foundation. It is as simple as that.
THE COURT: All right. Objection overruled.
(The following proceedings were held in open Court:)
THE COURT: Madam reporter, can you go to 4:30? You want to reposition yourselves?
(Brief pause.)
MR. CLARKE: Back to the drawing board. I like that. Dr. Cotton, just a few more questions at the board. You have described the basic method by which frequencies are calculated for a single marker; is that right?
DR. COTTON: That's right.
MR. CLARKE: What happens when you encounter more than one marker?
DR. COTTON: You calculate the frequency for the bands in the first marker. That pair of bands calculate the frequency for the pair of bands in the second marker, and to determine the overall frequency for those--that combination of bands from the first marker and the second marker, you multiply those frequencies together.
MR. CLARKE: Now, you mentioned--and if you would describe--the fact that you make an assumption not--well, let me rephrase that. You've described the fact that in using these multiple markers, more than one genetic marker to calculate a population frequency estimate--and you made a comment about the necessity that they not be related to one another in some fashion. Have I characterized that correctly?
DR. COTTON: You're close. That they not be--that--the assumption is that they are inherited independently.
MR. CLARKE: What does that mean?
DR. COTTON: It means that--umm, let me use a very sort of trivial example. Suppose you were looking at a combination of how many people had red hair and green eyes. What it would mean is that the trait for hair color and the trait for eye color didn't affect one another. That is, if you had red hair, you wouldn't automatically have green eyes. Hair color and eye color aren't really a great example of that, but the point--the point works anyway. That is, umm, you don't--you can not and should not multiply these characteristics together if the inheritance of one of them is somehow connected with the inheritance of the other.
MR. CLARKE: Okay. And that's the general concept of using multiple markers in an appropriate fashion?
DR. COTTON: They need to be independent of one another.
MR. CLARKE: While I have you at the chart and kind of as a last area, you've given this example of calculating frequencies or how that calculation process is done at one genetic marker. Can you actually give us an example by assigning some frequencies to, for instance, two of the bands as one of the sam--excuse me--on one of the samples and then calculate the approximate frequency at that genetic marker?
DR. COTTON: Yes. If we just use our sample a here--
MR. CLARKE: All right.
DR. COTTON: --and we say that--we'll just draw it down here. And that the frequency for this band was the band that's 5,000 base pairs was .3 and the frequency for the band that's 2,000 base pairs is .1 and a factor of two gets added to this or actually multiplied is what I need, that falls out of the fact that for any combination of two characteristics, there's two ways you can get that combination. And in this example, you could have inherited the upper band from your mother and the lower band from your father or you could have inherited the up--the reverse, the upper band from your father and the lower band from your mother, and that results, when you do the math, in requiring that you have a factor of two here. So for the frequency for the pair of bands in sample A, it would be two times .3 times .1.
MR. CLARKE: And what would that work out to?
DR. COTTON: Can you give me a calculator?
MR. CLARKE: You need a calculator? If I give you--
DR. COTTON: .03 times 2 would be .06 I guess.
MR. CLARKE: And would that mean that that's the approximate frequency in your example of having those two characteristics in various populations or a single population in this example?
DR. COTTON: That's right. Based on our little tiny database here and assuming I did that in my head correctly, it would be .06.
MR. CLARKE: Okay. Very good. All right. If you could then--
MR. CLARKE: Your Honor, I'm finished with the chart at this point.
THE COURT: All right.
MR. CLARKE: And if you could retake the witness stand, Dr. Cotton.
DR. COTTON: Okay.
(The witness complies.)
MR. CLARKE: Now, Dr. Cotton, did your laboratory receive evidence in this case before the Court today?
DR. COTTON: Yes, we did.
MR. CLARKE: As far as receiving that evidence, when it first--well, first of all, did it arrive on the same date or different dates?
DR. COTTON: All of the evidence did not arrive on the same date.
MR. CLARKE: I'm going to show you, if I may, a series of boards that appear to depict or appear to include photographs of various containers of evidence. Have you had an opportunity to look at some boards that I just described before today?
DR. COTTON: Yes, I have.
MR. CLARKE: And did you have the opportunity to look closely at those photographs to compare the items shown in those photographs as well as the dates found on those boards and compare those to your own records from the laboratory as to the dates various items of evidence were received at your laboratory?
DR. COTTON: Yes, I did that.
MR. CLARKE: All right. And referring initially to a large board marked People's exhibit 177-A, and in particular with respect to what appear to be three specific items that are numbered off to the left, item no. 7, 12 and an item marked "O.J. Simpson blood exemplar," did you have an opportunity to look at those photographs and the dates that are listed un--I'm sorry--under the column marked "to cellmark"?
DR. COTTON: Yes, I did.
MR. CLARKE: Did you receive each of those three items on the date after the date noted to the left of the photographs under the column "to cellmark" for those three item numbers?
DR. COTTON: Yes. That's right. That--I went to our records, to the case folder. I looked at the sheets that were used to log in the evidence which record the date the evidence was received, and for each of those items, the date we received it was after the date that's displayed on the chart.
MR. CLARKE: All right. And that would cover the three items that I just described?
DR. COTTON: That's right.
MR. CLARKE: All right. I'm going to ask you to look at another chart which I believe is exhibit 177--the letter I'll have to wait on--b as in boy.
(Brief pause.)
MR. CLARKE: And I think we're able to skip using boy. Let's go right to 177-C.
(Brief pause.)
MR. CLARKE: On this particular board, exhibit 177-C, and particular with reference to what's listed on the left as items nos. 47, 49, 50, 52 and 56, did you receive those particular items of evidence on the date--I'm sorry--the day after the dates listed on the column for each item labeled "to cellmark"?
DR. COTTON: That's correct.
MR. CLARKE: All right. Then if we could move to the next board, which I believe is 177-D as in David.
(Brief pause.)
MR. CLARKE: And referring you to 177-D, in particular, the items that are labeled, "Nicole Simpson blood exemplar," "Ronald Goldman exemplar" and "item no. 78," did you receive those items on the date--I'm sorry--the day after the specific dates listed under your column or under that column labeled "to cellmark"?
DR. COTTON: Yes, we did.
MR. CLARKE: With regard to item no. 78, can you tell us exactly what that item contained when it was received in your laboratory?
DR. COTTON: Yes, but I'll need to refer to the notebook.
MR. CLARKE: And that's the two notebooks you earlier used?
DR. COTTON: Yes.
(Discussion held off the record between the Deputy District Attorneys.)
(Brief pause.)
DR. COTTON: Item 78 would have been a single bloodstain swatch.
MR. CLARKE: As far as this term--well, strike that. As far as the items on this board as well as the previous boards, did you at an earlier time look at the actual photographs up close to verify what's labeled on the various containers?
DR. COTTON: Yes. When I looked at the boards earlier, I checked for the initials of our analyst and the written dates on the envelopes as they're depicted, and I can read--I could read them off the photographs, and then I can check them--could check them against our records.
MR. CLARKE: That was what I was going to ask. Did you then compare them to your own laboratory records of the various items as they were identified to your laboratory as well as the days they were received?
DR. COTTON: Yes, I did.
(Brief pause.)
MR. CLARKE: Lastly, Dr. Cotton, referring you to what I believe is marked People's exhibit 209, which lists in particular off to the far right what appear to be four photographs of items that, according to the chart, were directed to your laboratory on April 3rd, 1995--first of all, have you had an opportunity to look at the photographs on this board as well?
DR. COTTON: I don't think that I've actually looked at these.
MR. CLARKE: Okay. We'll make arrangements for that and we'll return to it then.
DR. COTTON: Okay.
MR. CLARKE: Now, as far as the evidence that you received and these various items, with the exception of what's listed on this latest board, 209, were received in your laboratory and you were requested to test those various items?
DR. COTTON: That's right.
MR. CLARKE: First of all, what was the type of evidence that was contained in most of these envelopes?
DR. COTTON: Most of them were bloodstain swatches.
MR. CLARKE: Is that a common means of transmitting evidence from one location to another for typing?
DR. COTTON: Yes, it is.
MR. CLARKE: Is it common that materials or evidence such as that be shipped at room temperature, ambient temperature as you've used that term?
DR. COTTON: Yes, it is.
MR. CLARKE: Once those items were received in the laboratory, were they identified in the manner that you described earlier that evidence is identified when it's received in the lab?
DR. COTTON: Yes.
MR. CLARKE: Now, I would like to return, if I could, to your description of the earlier visit that included that by Dr. Blake and Dr. Lee.
DR. COTTON: Okay.
MR. CLARKE: You described the fact that there was evidence actually cut by Dr. Blake; is that right?
DR. COTTON: That's right.
MR. CLARKE: I assume that came at a time after the evidence was received in the laboratory by your lab?
DR. COTTON: That's right.
MR. CLARKE: Do you recall the date that that cutting by Dr. Blake took place on various items?
DR. COTTON: I don't independently recall the date right now. The notes made by the analyst reflect that the cuttings were made on 7-28-94.
MR. CLARKE: July 28, 1994?
DR. COTTON: That's right.
MR. CLARKE: Can you tell us exactly which items of evidence, that is by item number-- first of all, can you, in referring to the documents in your laboratory, describe for us item numbers as used by the Los Angeles Police Department?
DR. COTTON: Yes, I can.
MR. CLARKE: With respect to this cutting that occurred on this date that you've just described by Dr. Blake, can you tell us exactly which items were cut by him?
DR. COTTON: Yes.
MR. CLARKE: Okay. Could you do that then, please.
DR. COTTON: Now it's going to--let me just pull out from the binder the right pages so I don't have to keep moving back and forth.
MR. CLARKE: All right.
(Brief pause.)
DR. COTTON: The items that were dealt with on that day would have been-- you want me to just list them?
MR. CLARKE: Yes. That's fine.
DR. COTTON: Okay. Would have been item no. 78, item no. 56, item no. 52, item no. 47, item no. 12 and item no. 7.
MR. CLARKE: So six different items?
DR. COTTON: Yes.
(Discussion held off the record between the Deputy District Attorneys.)
MR. CLARKE: With regard to these specific items, are you aware that item no. 78 was stained, blood-stained material taken from the bottom of Mr. Goldman's boot?
DR. COTTON: Yes, I am.
MR. CLARKE: With respect to item no. 56, are you aware that that's blood staining removed from a shoeprint found at the Bundy residence?
DR. COTTON: Yes, I am.
MR. CLARKE: With regard to item no. 52, are you aware that that was a bloodstain recovered from the walkway or actually driveway of that same Bundy residence?
MR. NEUFELD: Objection, your Honor. This is coming in for the truth of the matter asserted.
THE COURT: Sustained.
MR. CLARKE: Going back to this cutting process by Dr. Blake-- first of all, Dr. Blake is not a member of your laboratory, correct?
DR. COTTON: That's right.
MR. CLARKE: Is an individual not employed by your laboratory cutting on evidence in your laboratory a part of your protocol?
DR. COTTON: No, it's not.
MR. CLARKE: Why did that happen?
DR. COTTON: Umm, we were asked specifically--
MR. NEUFELD: I'm sorry, your Honor. Could we have a sidebar before?
THE COURT: Nope. Proceed. It's done by Court order, correct?
MR. CLARKE: Is that correct, Dr. Cotton?
DR. COTTON: That's right.
MR. CLARKE: And you followed that Court order?
DR. COTTON: Yes, we did.
MR. CLARKE: As far as a cutting-- and first of all, can you tell us approximately how much was cut off by Dr. Blake of these items of evidence?
DR. COTTON: He cut approximately 10 percent from each stained swatch.
MR. CLARKE: Now, without going into the actual number of swatches for the other five items, that is other than item no. 78-- first of all, did the number of swatches for each item vary?
DR. COTTON: Yes, it did.
MR. CLARKE: Did Dr. Blake cut off 10 percent of each and every swatch amongst this group of six evidence items?
DR. COTTON: Yes, he did.
MR. CLARKE: And as I--you I believe testified earlier, those 10 percent portions were maintained in the custody of your laboratory?
DR. COTTON: That's correct.
MR. CLARKE: This 10 percent portion, is there anything unique about 10 percent? In other words, is that a number that was just kind of picked out of thin air or what?
DR. COTTON: As part of our routine procedure, we normally set aside 10 percent of every sample whenever possible for future testing. So we made the Prosecution aware that we intended to do that, and some things followed, and following that was the Court order that Dr. Blake would take the 10 percent cuttings. So I have assumed that the 10 percent arose from our initial information that that's what we would normally take.
MR. CLARKE: Okay. When you say you would normally take 10 percent of a sample, is that in any other case? You'd do that yourselves?
DR. COTTON: In every case, whenever the size of the sample allows, we will save 10 percent of the sample for future testing.
MR. CLARKE: Do you have a term that you use to describe that 10 percent that you save when you're able to?
DR. COTTON: In the notes, it's just referred as a "FTS sample," FTS just standing for future testing sample.
MR. CLARKE: Are there circumstances in which you're unable to keep 10 percent for future testing purposes?
DR. COTTON: Yes.
MR. CLARKE: Under what circumstances?
DR. COTTON: Umm, basically there's two. One would be that the sample was simply so small that there was no way to physically remove 10 percent and still have enough left to test. Another thing--for example, if you had a single hair, you can't cut off 10 percent of the root of the hair. It's just too small to deal with. And the other circumstance would be, we might take a 10 percent cutting, have trouble with the original 90 percent and then go back and ask our client permission to use the remaining 10 percent; and if given permission, then we would go ahead and do that.
MR. CLARKE: As far as the keeping of this future test sample or 10 percent cutting, is it kept for any purposes other than simply your ability to go back and use it if necessary?
MR. NEUFELD: Objection. Irrelevant.
THE COURT: Overruled.
DR. COTTON: The future testing sample, this 10 percent, is just available for whatever future testing might be done. It's not-- I'm not saying that it's just for our, Cellmark's own future testing if we have a problem. The 10 percent is set aside. Should that 10 percent be--that 10 percent could be given to another laboratory working for either side to be tested later on.
MR. CLARKE: Can that future test sample be tested by the Defense in criminal cases?
DR. COTTON: Of course.
MR. CLARKE: Now, with regard to--and I'm referring now to the samples other than this initial set of six where Dr. Blake actually performed the cuttings. Did you take future test samples on the remaining items of evidence?
DR. COTTON: Yes, I believe so.
MR. CLARKE: Did you also receive known samples, that is known bloodstains from identified persons?
DR. COTTON: We received three known bloodstains. The actual identification of whom those bloodstains were from was not made known to us at the beginning and they were just identified as exemplar c-1, exemplar c-2 and exemplar c-3.
MR. CLARKE: So these known or three known samples were basically not known to you in terms of who they came from although you were made aware that they represented reference or standard samples from known people?
DR. COTTON: That's exactly right.
THE COURT: All right. Mr. Clarke, I need to stop you at this moment. We need to take a five-minute comfort break at this time, ladies and gentlemen. So let me ask you just to step back into the jury room. And, Dr. Cotton, you can step down and stretch your legs, and we'll take a brief recess.
(Recess.)
(The following proceedings were held in open Court, out of the presence of the jury:)
THE COURT: Let's have the jurors, please.
MR. NEUFELD: Judge, can we have a brief sidebar in reference to the Defense cuttings? I don't think the ruling from the Court permits testifying of that issue and getting into it.
THE COURT: How much further are we going to go, Mr. Clarke, on this?
MR. CLARKE: I don't have any more questions at this point about that. I haven't examined the rest, but I will overnight.
THE COURT: All right. The issue is dead for the afternoon then. Let's proceed. Let's have the jury, please. And after we conclude this, we'll take about a 10-minute break, then have our discussion about the proposed jury instruction.
MR. CLARKE: I'm sorry?
THE COURT: We'll have our discussion about the requested jury instruction, but take about 10 minutes in between.
(The following proceedings were held in open Court, in the presence of the jury:)
THE COURT: Thank you, ladies and gentlemen. Please be seated. Dr. Cotton, would you resume the witness stand. All the jurors have now rejoined us. And as I recollect, we were just talking about the designation of the exemplars by letter.
MR. CLARKE: Yes. Thank you, your Honor.
MR. CLARKE: So again, Dr. Cotton, as far as your laboratory was concerned at the time of testing, the identities of the persons from whom those three blood samples came from, known samples were basically unknown to your laboratory?
DR. COTTON: That's right.
MR. CLARKE: Now, after receiving various pieces of evidence in this case, was testing conducted on them using various DNA typing approaches?
DR. COTTON: Yes.
MR. CLARKE: And would that be the RFLP as well as PCR approaches?
DR. COTTON: That's right.
MR. CLARKE: How did you make decisions about which items, whether evidence and known samples or known samples and which approach was going to be used with those various items? How do you do that?
DR. COTTON: Well, for some of the items, we were requested to do a particular thing. Most of that would be PCR. For some of the items, umm, we were directed to do testing, and if possible, do RFLP testing. So for those items, we would have made an assessment of the quantity and quality of DNA that was extracted from those items, and then we would have proceeded to make some judgment as to whether we should try RFLP or go straight to PCR.
MR. CLARKE: As far as the actual testing conducted in this case, do you have with you today the autorads from RFLP testing that was done?
DR. COTTON: Yes, I do.
MR. CLARKE: Do you also have photographs from the various typing strips that were interpreted or results were obtained from after PCR amplification?
DR. COTTON: Yes, I do.
MR. CLARKE: As far as the testing itself--and I'm referring to all of the testing conducted in your laboratory--did the controls work properly?
DR. COTTON: The controls worked properly for all of the testing with one exception, and we had a--very faint dots in one reagent blank for one of the PCR tests.
MR. CLARKE: All right. We'll return to that later. Was that, to your knowledge, the only instance in which that occurred?
DR. COTTON: Yes.
MR. CLARKE: Incidentally, why was--does the fact that you weren't informed of who these reference samples play any role in the testing itself?
DR. COTTON: No, it doesn't.
MR. CLARKE: Why didn't you know who they were from?
DR. COTTON: Umm, I'm not sure who made that determination. I've been assuming that it was--
MR. NEUFELD: Objection as to assume.
THE COURT: Sustained.
MR. CLARKE: Was a determination--I'm sorry. Was it a determination made by you?
DR. COTTON: No.
MR. CLARKE: Was it a determination made by anyone in your laboratory?
DR. COTTON: No.
MR. CLARKE: In the course of testing--well, let me rephrase that, go back one step. As far as your not being informed of the identity of those known samples, is that unusual or normal?
DR. COTTON: It's unusual, but it's not the only time that we've received samples coded in some manner.
MR. CLARKE: As far as the results that were ultimately obtained, did they include indications to you of mixtures of DNA?
DR. COTTON: There is--there are two samples in the results that are clearly mixtures of DNA.
MR. CLARKE: What is a mixture of DNA? Can you describe that briefly?
DR. COTTON: Well, in this circumstance, we're talking about the idea that the DNA that was extracted from the sample contains DNA from more than one person.
MR. CLARKE: How are you able to determine that a sample has DNA from more than one person?
DR. COTTON: For an RFLP test--well, actually it's the same for both. Any time that you look at a single genetic location and you see more than two types for an RFLP test, that would be, instead of just seeing two bands, you saw three, or for a PCR test, would be instead of seeing just two types like an a and a B, you would see an A, a B and a C. Under those circumstances, you know immediately that you have DNA from more than one person.
MR. CLARKE: As you've used the term earlier, is that "contamination" as you've used the term?
DR. COTTON: If you view contamin--if you--let me back up a second. If you have--if those two DNA's are part of the original evidence as it was left at the scene, then in my view, that's not an instance of contamination. That's the true nature of the sample. If you want to back up and say are these sterile samples, no. We've got two DNA's that are mixed together, but that's not a good reference point for this kind of discussion.
MR. CLARKE: With regard to the procedures--and you've had an opportunity to review all of the material relating to this case?
DR. COTTON: I have.
MR. CLARKE: That includes the autorads themselves?
DR. COTTON: It does.
MR. CLARKE: Does it include photographs?
DR. COTTON: Photographs of results?
MR. CLARKE: Yes.
DR. COTTON: Yes.
MR. CLARKE: Have you had an opportunity to review all of the documents that you've described are kept in the course of testing in your laboratory?
DR. COTTON: Yes, I have.
MR. CLARKE: From that review of the various documents and data, whether photographs or autorads themselves, do you have an opinion about whether or not correct procedures were used by the two analysts in this case, Julie Cooper and Paula Yates?
DR. COTTON: Yes, I do.
MR. CLARKE: What is that opinion?
DR. COTTON: My opinion is that the procedures in the protocol were followed correctly in the testing in this case.
MR. CLARKE: As far as the procedures that were used in this case, in your opinion, are those proper scientific procedures for DNA typing?
DR. COTTON: In my opinion, they certainly are.
MR. CLARKE: Now, with regard to--and let's focus immediately on RFLP testing itself. Do you have with you an autoradiograph that depicts the three standards or known samples in this case?
DR. COTTON: Yes.
MR. CLARKE: And have you also-- well, first of all, do you have the original autoradiographs with you?
DR. COTTON: Yes, I do.
MR. CLARKE: Do you have a policy in your laboratory about releasing original autoradiographs?
DR. COTTON: Yes, we do.
MR. CLARKE: What is that policy?
DR. COTTON: We don't release them until we come to Court. If they are left as part of the Court record, that's okay. But prior to that, we maintain the original data, which is the autoradiographs, in our custody.
MR. CLARKE: For what reason? Actually, let me rephrase that question. In terms of the originals themselves, do they represent the best data available?
DR. COTTON: They do.
MR. CLARKE: All right. With regard to the autoradiograph I mentioned that deals or demonstrates the results obtained from DNA from the three identified samples, that is without name, but identified as known persons, does that autorad--has it already been marked in this case?
DR. COTTON: They all have the three known people on them.
MR. CLARKE: Okay. Let's go back then to what I believe is exhibit 246 if I recall correctly.
MR. CLARKE: And may I approach the witness, your Honor?
THE COURT: You may.
MR. CLARKE: Showing you exhibit 246, can we use that autoradiograph to show what the DNA appears or what it appears like for the three known samples in this case?
DR. COTTON: Yes.
MR. NEUFELD: I'm sorry. May I just approach and take one look at what she's looking at?
THE COURT: Sure.
MR. NEUFELD: Thank you.
(Brief pause.)
THE COURT: That's People's 246.
MR. NEUFELD: Thank you.
MR. CLARKE: Your Honor, at this time, I have or actually the laboratory has made a number of copies of this particular autoradiograph that shows the three standards, that is the three known individuals. It has one evidence lane with nothing showing. And it would be my request that these copies be distributed to the jury.
THE COURT: Can I see that?
MR. CLARKE: Yes.
THE COURT: Have you shown them to counsel?
MR. CLARKE: They have one copy.
THE COURT: Mr. Clarke, may I see one of those, please?
MR. CLARKE: Yes.
THE COURT: I take it these are all duplicates of the same?
MR. CLARKE: Yes. Am I approaching in the wrong direction?
THE COURT: You want to hand it to Mrs. Robertson? I just need to see one of them.
(Brief pause.)
THE COURT: All right. And, Mr. Clarke, these are exact duplicates of 246?
MR. CLARKE: Yes.
THE COURT: And that's with item 56 removed, correct?
MR. CLARKE: I'm sorry?
THE COURT: That's with item 56 removed? Never mind. All right. Mr. Clarke, do you have enough to go around?
MR. CLARKE: Yes.
THE COURT: Mr. Neufeld?
MR. NEUFELD: I just hadn't seen the copies, your Honor. That's why I didn't--
THE COURT: Okay.
MR. NEUFELD: Sometimes there's some variation. That's all I--
THE COURT: Mr. Clarke, why don't you let Mr. Neufeld take a look there.
MR. NEUFELD: May I?
(Brief pause.)
MR. NEUFELD: Just one moment, your Honor. I want to compare the two.
(Brief pause.)
THE COURT: I take it this is for demonstration purposes at this point because we're not doing any comparison yet, correct?
MR. CLARKE: Only amongst the three knowns.
MR. NEUFELD: Your Honor, can we have a brief sidebar?
THE COURT: All right. With the Court reporter, please.
MR. NEUFELD: Thank you.
(The following proceedings were held at the bench:)
THE COURT: We are over at the sidebar.
MR. NEUFELD: The only question I have--maybe the Defense only gets the photographs, but all these copies show a clean pattern from Mr. Goldman. The one I was given shows it with other markings in the band.
THE COURT: Schmutz. We call it schmutz.
MR. NEUFELD: That's exactly what it was. This was one I was given in discovery.
THE COURT: Keep your voice down.
MR. CLARKE: I'm sorry. What is--
MR. NEUFELD: See the difference between the Goldman profiles and yours? The one you gave me has all the stuff in it. The band isn't sharp. Something else is going on in the lane. I don't know what it is.
MR. CLARKE: They look identical to me. They were made at the same time.
MR. NEUFELD: The only one that has all this schmutz on it is mine. Look at yours. None of them do.
MR. CLARKE: That's not true. They were made at the same time.
THE COURT: At this point, the objection is overruled. This is just for demonstration, not for comparison purposes.
MR. NEUFELD: I'm not even objecting.
(The following proceedings were held in open Court:)
THE COURT: All right. Mr. Clarke, you may proceed.
MR. CLARKE: I'm missing one autorad, your Honor. That's an acceptable place for it. I have 17 in my hand and I actually have one. If the Court would keep that.
THE COURT: Well, thank you.
MR. CLARKE: Dr. Cotton, showing you a series of x-rays that have not been marked as yet--
MR. CLARKE: Actually, does the Court prefer they be marked or not if I'm going to ask that they be distributed to the jury?
THE COURT: Let's call these--actually give them a separate number. Since they're going to be exhibited to the jury, they should be part of the record.
MR. CLARKE: All right. Would that be 256 then?
THE COURT: 256. Collectively 17 copies of autorads.
(Peo's 256 for id = 17 copies of autorads)
MR. CLARKE: Dr. Cotton, have you had an opportunity to look at the 17 copies of the autorad that will be marked People's 256?
DR. COTTON: Yes. I looked at them when I was still at the lab before I gave them to you.
MR. CLARKE: And are they in fact copies, as is exhibit 246, of one of the autorads in this case?
DR. COTTON: They are.
MR. CLARKE: With respect to those autorads as contained in both 246 and now in 256, does that autorad represent data from this case?
DR. COTTON: Umm, yes, it does.
MR. CLARKE: And what does it depict just in general terms as far as samples?
DR. COTTON: Umm, the samples that are on here besides the control samples are the known blood from Mr. Simpson, the known blood from Nicole Brown and the known blood from Ronald Goldman, and also on this film, had there been anything to see, would have been analyzed item no. 56.
MR. CLARKE: Is that the shoeprint?
DR. COTTON: Yes. There is, however, no DNA banding pattern that was obtained from item no. 56.
MR. CLARKE: So can we use this autorad as a demonstration of the RFLP process and differences if any between the three known persons in this case?
DR. COTTON: Yes, we can.
MR. CLARKE: As far as this autorad itself, is it labeled with names for each of these three individuals, Mr. Simpson, Nicole Brown and Ronald Goldman?
DR. COTTON: Yes, it is.
MR. CLARKE: Were those labels put on at some later date after the autorad was initially produced?
DR. COTTON: Yes, they were.
MR. CLARKE: In other words, during the testing, you didn't know who the individuals were, correct?
DR. COTTON: That's right.
MR. CLARKE: That is, the identities of these known samples?
DR. COTTON: That's right.
MR. CLARKE: Were the labels then put on after your results were reported?
DR. COTTON: Yes, they were.
MR. CLARKE: All right. Your Honor, I was going to ask that those be distributed to the jury and then utilize the original on the elmo so that the witness can describe what's shown on this autoradiograph.
THE COURT: Well, given the hour, I would suggest that we distribute them--since we've held it up and shown them, let's let the jury see what an autorad looks like. Then we'll start with that tomorrow morning.
MR. CLARKE: Very good.
THE COURT: All right. But let's let the jury see what an autorad looks like.
MR. CLARKE: May I hand them to the jury then?
THE COURT: You may.
(Brief pause.)
THE COURT: All right. Ladies and gentlemen, if you'll just pass them down then to your right. And, Mr. Clarke, if you will collect those from the bailiff, please. All right. Ladies and gentlemen, we are going to take our recess for the afternoon. Please remember all my admonitions to you; do not discuss this case amongst yourselves, do not form any opinions about the case, don't conduct any deliberations until the matter has been submitted to you, don't allow anybody to communicate with you with regard to the case. And we'll see you here tomorrow morning, 9:00 o'clock. And, Dr. Cotton, tomorrow morning, 8:45. And I'll see counsel in 10 minutes. All right. We'll stand in recess.
(Recess.)
Appearances: (Janet Levine and Alvin Michaelson, esquires, appearing on behalf of Mr. Kardashian.)
(The following proceedings were held in open Court, out of the presence of the jury:)
(Discussion held off the record.)
THE COURT: Let me invite counsel to step back in the jury room to discuss that matter and I need to talk to counsel on instructions on another matter.
(Discussion held off the record.)
THE COURT: Mr. Darden, I need to do another hearing here, so if I can get you and counsel to step back in the jury room and Mr. Clarke and Mr. Neufeld and I can talk about these proposed instructions.
MR. CLARKE: Actually, Mr. Harmon will be returning. I thought he would be back by now.
MR. NEUFELD: Your Honor, are we also going to resolve the issue of mixed stain frequencies now?
THE COURT: Counsel, I indicated I was going to read the case authority that you cited. In case you haven't noticed, I have been sitting here all the time. I haven't had much time to do that.
MR. NEUFELD: I agree.
(Brief pause.)
THE COURT: While we are waiting, let me ask an off the record question.
(Discussion held off the record.)
THE COURT: All right. Let's go back on the record in the Simpson matter. The Defendant is present with his counsel. The People are represented. The jury is not present. Mr. Scheck, you have offered to the Court a proposed instruction on DNA statistics and I take it you are urging the Court to give an instruction or something similar to this prior to the actual presentation of the statistical analysis of DNA?
MR. SCHECK: Yes.
THE COURT: I will hear your argument.
MR. SCHECK: Your Honor, the trick in drafting a jury instruction I think is to try to make it balanced, try to make it simple, try to make it clear, try to marshal the general arguments in a way that will aid the jury in assessing the evidence and not confusing it. I dare say that these short four paragraphs took me hours in terms of trying to state things in a way that would be balanced and would direct the jury towards an understanding of the issues. As a backdrop to this, I'm sure the Court is aware of all the articles that both sides cited in the course of briefing on the Kelly-Frye questions and on the statistical issues and on our notice of objections with respect to the issue of population frequencies versus error rates and other factors which may or may not be quantifiable in terms of how one gets to a DNA. The national research council, of course as I'm sure the Court is familiar, addressed this Court very specifically in its chapter on statistics where it indicated that the question of population frequencies of a coincidental match is a separate and independent issue from a match that would arise as a result of laboratory error or mishandling of samples, obviously. That is all we really want to direct the jury toward and that is that there is a danger that has been recognized in all the decisions on this issue, whether the DNA statistics are admitted or not, that is recognized in all the literature I'm sure the Court has read in the national research council report, that once the jury sees these astronomically rare frequencies for various items of evidence, there is a danger that they will jump to a bottom line and think that these frequencies represent, no. 1, a probability that the Defendant is the source, for example, of certain samples, and so forth, as he was at the Bundy crime scene on June 12th. In other words, they confuse it as a source probability. Or no. 2--or they would assume it to be a probability of guilt because the numbers are that astronomically rare in DNA test results that they will divert and mislead the jury unless they have guidance as to where the different arguments lie. This instruction is short and it is correct scientifically and I think it is a fair statement of just where the issues litigated lie in this case. That is to say, that the Prosecution is presenting DNA banding patterns about the likelihood of different people coincidentally having the same banding patterns. That is what frequency evidence is. I don't think there is any dispute on the other side that the number represents anything other than that.
On the other hand, as we point out, that these statistics are not an estimate of the likelihood of a false or misleading match of DNA banding patterns to the errors in the collection or handling of samples and errors in laboratory analysis or intentional tampering of samples. And we just point out that those are two independent issues. And then frankly the last sentence I think that would be customary in any jury charge is particularly important from in terms of probability theory and statistical theory and that is they should consider all the evidence in this case when evaluating the weight of DNA evidence. And again that is just a caution in very neutral terms, I think, don't jump--consider all the evidence in the case, and this obviously is important evidence, but it is only part of what--all the evidence in the case. It seems to me it is a short, neutral instruction that doesn't devalue the evidence the Prosecution is presenting; it only guides the jury in terms of where the various contentions of the parties are. And we tried to write this in as neutral a way as possible. That is the whole purpose of the jury instruction.
Now, the Court did make an inquiry about have people given the notion of preliminary instruction some thought? Now, we initially gave some consideration to proposing an instruction at the very beginning of the trial, but it was clear that before the jury even gets exposed to the DNA procedures and how one goes about calculating frequencies, it is impossible to begin an assessment or to even take in where such an instruction would go. They would be unable to evaluate the contentions of the parties and what they should be focusing on from both points of view. Now, we are getting close to the stage where I think that it is becoming clear to the jury what kind of evidence they are going to be considering, what kind of decisions they are going to be made. Now is the time where guidance would be most appropriate, particularly when the numbers are coming in, so they understand what it is and what it isn't. There is a tremendous need, the literature demonstrates, in terms of the way lay people assess statistics, to have some judicial intervention here to guide the jury on evaluating statistics.
The Kohler article is an actual study that we cited to the Court, and I'm sure the Court reviewed, would show the kind of effects that a very, very rare frequency calculation can have, as opposed to--and we don't have quantification of error rates here of any sizable number for all the labs, but as opposed to if we just assume an extremely high error rate and we assumed an extremely rare frequency, people have trouble assessing that in a fashion that is consistent statistically. That is to say, that they will tend to do something like split a difference. If you tell them that the error rate is one in 200 for false positive and the frequency of a coincidental match is one in a billion, they may split the difference and that just doesn't make any sense in terms of evaluating evidence, so they just need guidance, as the national research council urges, that the possibility of a false or misleading match due to sample handling error is a separate and independent question from these frequencies about coincidental matches. And I think just that much guidance stated in a clear and neutral way from the Court would be of great assistance in assessing what the evidence is and what it is not. That is what we've asked for and I think it is really important. I think it is one of the most important decisions the Court will make. You asked about instructions. I personally worked with Professor Franklin Zweig and many Prosecutors and people from the FBI and judges at the national council of state courts that have been trying to review DNA evidence in terms of how judges should deal with it, what kind of charges would be appropriate. We have also worked with the Federal Judicial Center which has made the efforts in this direction. Courts are struggling with it. We didn't have the big Frye hearing in this case in terms of all the different systems, but what we do have here and what is very much alive and is not waived and is completely the province of this Court is the 352 problem. That is, how are you going to instruct this jury to deal with the statistics? And we have tried to make as balanced and as objective and succinct an effort in this direction, just as a preliminary charge as possible, so that the Court could do that. The last factor I would cite goes back to the classic argument by Lawrence Tribe concerning trial by mathematics and the quotations we put in our previous briefs and that has to do again with the notion that if you have one variable here that you can't quantify, and especially when it comes in in extremely rare form, one in a billion or one in a billion versus one in a trillion in certain instances, and then you are dealing with other variables in the proof which are extremely important, as the Cella case points out in this jurisdiction, and even Collins I think is relevant precedent on this issue, but the point is when you do--when you deal with unquantified variables when the jury should assess it, is the danger is a 352 problem that the jury is going to focus on the only quantified variable to the exclusion of all the other issues that they also in fairness should consider. And that is all we are asking the Court to do, is to give some guidance to the jury in their assessment, not take the stand one way or the other, just tell them what it is and what it isn't, and I think it would greatly assist in their evaluation of the witnesses and the testimony in the case.
THE COURT: All right. Good afternoon, Mr. Harmon.
MR. HARMON: Good afternoon, your Honor. Once again Mr. Scheck and I have the most important issue in this case before you. Somehow whenever he addresses you, it is the most important issue. Quite frankly, this is it. This is the most critical thing you will have to decide. Well, I'm not agreeing with him that it is balanced. I don't agree that it is simple. I don't agree that it is clear. But it is totally unnecessary to do now, and that is the simple matter that I think you should address or you should resolve this on. If you listen very carefully, about two-thirds of the way through Mr. Scheck's presentation to you he admitted to you that this instruction is to inject the contentions of the parties. Now, that is the problem. We don't--the jury doesn't decide this based on contentions of parties, even though that has been injected. At every turn people were allowed to do that. There are no contentions on these issues. We have evidence at this point, everything that is in the briefs that were filed that they, with the sage advice of counsel, waived their admissibility hearing for, that is water over the damn. The general instructions do suffice. You asked if there have been any special instructions in this area. The case that was granted review by the Supreme Court, one of the three cases, People versus Soto, had a special instruction requested. It was different than this. I don't want to mislead you. I don't have it. It was read to me over the phone. It had to do with not convicting just based on the probability evidence. But it is another instance of attorneys, Defense attorneys requesting, and I can get that for you, I don't--got lost in the fax wire somewhere, but it was read to me this morning--it is mentioned in the now citable People versus Soto opinion, and the text is not--it is not like this but it is another instance of a special instruction that was denied by the trial Court. The appellate Court agreed with the denial of this. But there is a general disfavor for special instructions at any point in the process. Let me inject a little humor into this. Let's just imagine that Max Cordoba, who is going to come out and testify about whatever it is that he's alleged to have said, and let's imagine that we say, wait a minute, your Honor, this is the most important issue you are going to hear in this case, this is critical, because the whole domino effect could come into play. And we have said to you, your Honor, this is it, you have to address this right now. It is a lot easier without everybody in here, too, to have these discussions.
MS. LEWIS: We are on the record.
THE COURT: Which is why the TV cameras should not be here.
MR. HARMON: You are about to be presented the testimony of Max Cordoba who will testify about A, B and C about Detective Fuhrman. You must be very careful in considering the testimony of Max Cordoba because he may have had this in a dream, he may have dreamed that he heard it, he may have heard it, then dreamed that he heard it, and before you can consider the testimony of Max Cordoba you have to decide whether my instruction made any sense and whether or not he really did hear the things at hand. Now, you know, we've gotten carried away I think with all the sanctions and things and I think when you start giving special instructions at this point in the case, everybody is going to be lined up, we have all these specialists here, we are all going to be lined up saying this is a special instruction that is indispensable to the fair resolution of this case. Paragraphs 2 and 3--why now? All of the things alluded to may never come into evidence in this case. Just because they've got all these psychologists writing articles about scientific issues doesn't mean that there is going to be any admissible testimony on these issues. Paragraphs 2 and 3 are argumentative. Scientists, real scientists, not psychologists, would agree that the true way to resolve whether any laboratory error was made is to retest the evidence, not to quibble and extrapolate industry-wide error rates. That is the science that we are dealing with here in this area. 2 and 3 are totally misleading in that context.
THE COURT: What is your opinion of the first paragraph?
MR. HARMON: I have a problem--well, first off, I have a problem with the word "likelihood" and I am really surprised to see it in there, because if you look in the dictionary, as I did, "likelihood" equates to probability, and I always thought that was a Defense no-no, that we couldn't talk about probability. If you give this instruction, and I think that some instruction you may give at the close of all the testimony, the correct word to insert in the place of "likelihood" is "possibility," because there may be no likelihood that a laboratory committed an error, that is a probability. And it may sound like semantics, but if you look in the dictionary for the definition of the two words, I think you will see a profound difference. But I mean the real issue is there is a general disfavor of special instructions. There is no basis for some of the information that is contained in that instruction now.
THE COURT: Let me ask you this, Mr. Harmon: As a general proposition, though, given the unusual nature of DNA evidence and the manner in which it is presented, don't you think some special instruction would be warranted at least explaining to the jury in as concise a way as possible what it is that this evidence can do and what it can't do?
MR. HARMON: You know, I think philosophers have struggled with how to express that to them. I am not disagreeing with you, but I think words develop profound importance; one word in place of another, a comma in a different position. I don't think this is it because it alerts them to something that may never manifest itself, and I mean it really does raise this issue that Mr. Neufeld didn't want to have us getting into, and that is Defense access to evidence, which is lurking around in the background of this case, and will be for the next few weeks, as the answer, the scientific, the hard scientific answer to all of these things, so, umm--but I think the real struggle is how to do it. And you know, one of the real problems is, it is clear they have been thinking about this for a long time. I appreciate how hard it was for Mr. Scheck to come up with this, but it is obvious that this was something that was contemplated for so long. And I don't think it is fair and appropriate to lay it on us the day of the testimony that they expect it to begin. That--I don't think that is appropriate. And I wish we could change things so that we have fair notice and appropriate time, regardless--you know, Court time is valuable, but this is not the kind of sandbagging--if this is the most important issue, then it should be important to us and we should have notice of it.
(Discussion held off the record between the Deputy District Attorneys.)
MR. HARMON: Miss Lewis advises me that you are on the Caljic committee and I can imagine the kind of intense discussions that you have about semantics and sentence structure, particularly when you realize the profound effect. You know, we can all argue everything that is in here, if there is testimony, and we can conform our arguments to the standard Caljic instructions. We have seen cases get reversed because a Judge with a keen insight and following the case before him, decides to make a subtle change in it. And I don't think that there is safety in being conservative, but given that this was just dropped on us this morning, it is something that we will have plenty of time to resolve before the jury is instructed.
THE COURT: All right. Mr. Scheck, any brief response?
MR. SCHECK: Yes. First of all, at least I'm consistent. I'm sure the Court recalls that I brought this to the Court's attention many times on this 352 issue and talked about the need for guidance in an instruction as being critical. Mr. Harmon has a way of trivializing this issue which I think is inappropriate. We all know that instructions with respect to special witnesses are necessary and are the obligation of the Court to clarify matters for a jury. There are special instructions, no doubt, on informants that are given, on experts, on eyewitness identification. I don't know the precise forms of them in California, but I know they exist and I know they exist in other jurisdictions. DNA and statistics is definitely one of those areas and it has been the issue we have been addressing to the Court and I'm sure the Court has given some profound thought to it already because even though we never litigated the hearing, the 352 objection has been abiding and has been there. If Mr. Harmon doesn't like the word "likelihood" in this instruction, I would readily accede to the word "possibility." I think they've had fair notice that this was an issue that we all had to resolve. This is my best efforts at it, trying to look at it from the Court's point of view, because that is the way lawyers should act when they submit instructions. And it seems to me that the Court should--my request would be that if they have any counter-instructions or suggestions or there is something they don't like in this, that they should indicate precisely what it is. I think we made our best efforts to give guidance and I think the Court's obligation here I would hope is to give guidance. This is the time to give guidance. This is something that I think other courts in your position in the future would have to do and this is the time. We have been talking about it for a while.
THE COURT: Well, unfortunately the California Supreme Court's granting hearings on three significant DNA cases has pretty much muddied the waters, at least as far as trial courts are concerned at this particular point in time. Mr. Scheck, I agree with you as a matter--as a philosophical matter that this is something the Court probably should instruct on. I also agree with Mr. Harmon's argument that we don't necessarily know how the issues have been framed just yet and perhaps at this particular instruction at this point is premature. But I do think that some instruction perhaps at this time, within the context of our discussion over the next couple of weeks, might be appropriate. I'm going to ask Mr. Harmon to submit--Mr. Harmon, I take that it Mr. Clarke is going to be carrying the ball for the next day or so?
MR. HARMON: At least.
THE COURT: Okay. How does Monday sound for a proposed instruction?
MR. HARMON: Fine.
THE COURT: All right. I know I would like to do it sooner, but I think within the context of our discussions I think that will be sufficient time. All right.
MR. SCHECK: We have one other issue, your Honor.
THE COURT: Yes.
MR. SCHECK: A prophylactic one, and that has to do with some guidance on what evidence can be elicited with respect to the activity of Defense experts concerning the evidence and what can't be and what kind of statements or inferences can be drawn.
THE COURT: Mr.--let me ask Mr. Clarke, what are you going to do with this at this point?
MR. CLARKE: Actually if I can check--if the Court will just give me two moments, I don't believe I have another reference, but I will check.
THE COURT: All right. All right.
MR. SCHECK: The only concern we had there, and I think it would be important to have some notice ahead of time when this issue is going to arise, is that--
THE COURT: Right. That's fair.
MR. SCHECK: --we have that problem that we didn't want to object in front of the jury because--
THE COURT: And I saved you the trouble.
MR. SCHECK: You saved us the trouble on the issue of the Court order, but where it arose again, and we didn't object and just because we stood up and made an objection and we decided to talk about it later, is that we talk about the ten percent. Is it--the problem is are we going to get back into litigation in front of this jury as to whether the Defense should have been entitled to more or ten percent of what at what time for what kind of tests? These under 352 I think are just inappropriate and more trouble than it is worth.
THE COURT: All right. Mr. Scheck, let's do this--Mr. Clarke, let me direct you--if I can have your attention for two seconds.
MR. CLARKE: Yes.
THE COURT: Let me direct you to notify the Court before you get into an area of questioning regarding Defense experts at cellmark and then we will take that up at the side bar.
MR. CLARKE: Actually I have reviewed that. There are two questions. One, I was going to ask the witness if Dr. Blake did anything to contaminate any of the samples in the witness' opinion in the course of this cutting process. And then, lastly, were--
MR. SCHECK: You will say no, right?
MR. CLARKE: --were all of the raw data--
THE COURT: He spit on it.
MR. SCHECK: He sneezed on it. He flaked dandruff on that.
MR. SHAPIRO: We have another term for that.
MR. CLARKE: Actually, no other reference to Defense experts.
THE COURT: Did Dr. Cotton observe anything during the course of this procedure that would indicate that anything he did was other than in a scientifically approved manner that the ten percent was taken.
MR. CLARKE: Correct.
THE COURT: All right. I don't think that is an objectionable question.
MR. SCHECK: No. I mean--that is all right.
THE COURT: All right. Thank you, Mr. Clarke. Okay. Miss Levine, any progress report or is the other side conferring or what is our status?
MS. LEWIS: No, your Honor, I will--
THE COURT: Miss Lewis.
MS. LEWIS: Since we were just kind of given the stipulation just now and only one copy so that Chris Darden and I had to share it, we wanted an opportunity just to look at it. I've already found a couple of questions that weren't answered in here. It is not--there is no factual basis for it, it is not signed, it is not under declaration of perjury.
THE COURT: This is a proposed stipulation.
MS. LEWIS: We, as the Prosecutor, don't know the facts so how can we stipulate to something that we have never heard Mr. Kardashian say?
THE COURT: Miss Lewis, the whole purpose of this exercise is to see if you can informally figure this out, because having counsel for a Defendant called as a witness is something the trial Court has an obligation to avoid as much as possible. You know, I agree with you, it may not be possible to avoid, but I am mandated by the case law to at least make the effort to avoid that end, if we can do that by counsel meeting, conferring with each other to seeing what the offers of proof are or--this is an off-the-record conference between counsel, and if you can resolve it, fine. If not, then what is going to happen is I suspect we will have to have an out-of-the-presence hearing and have Mr. Kardashian called as a witness and find out what the factual record is since there is no depositions in criminal matters. That is what may have to happen.
MS. LEWIS: I think that is probably the likeliest scenario, your Honor.
THE COURT: I am trying to avoid that.
MS. LEVINE: Your Honor, I think it is very unlikely. I went back and looked at 402 after Miss Lewis' reference to it and it talks about the determination of a preliminary fact. When we mentioned that back in the jury room, Miss Lewis and Mr. Darden, they said the preliminary fact is the truth of the testimony and that is obviously not the type of preliminary fact 402 talks about or else every witness in every piece of evidence would be subject to that.
THE COURT: Counsel, let's cut to the chase. The real chase is, is it possible that Mr. Kardashian could offer some relevant testimony? The answer is could be because of the videotape that we have all seen of Mr. Kardashian with the luggage. The luggage tag confirms that that is the luggage that was in Mr. Simpson's possession at dates that are pertinent to this case. Question. And we don't know where the clothing is, allegedly, that the Prosecution's theory is that Mr. Simpson was wearing it. So the Prosecution has good faith probable cause to investigate further. The question is how do we do that?
MS. LEVINE: That is--this seems appropriate, your Honor, and I think that the way to do is try, like lawyers and counselors, to sit down and figure it out and that is what we attempted to do. I prepared a proposed--and it is labeled "draft stipulation" on the top. I gave a copy to Mr. Douglas who had some suggestions and wanted to look at others. I give a copy to Miss Lewis and she immediately told me she wanted him to testify without looking at it. I don't think that is appropriate. I think we should sit down and try to work it out. If they have some contrary facts, and we have asked and they do not, they should bring those to our attention. This is, umm, really something that is ripe for working out.
THE COURT: All right. Counsel, I haven't seen the declaration, obviously, but obviously what they want to know is what was in the bag and where did it go and those questions--two questions need to be answered.
MS. LEVINE: And they are answered, because as the draft proposes, Mr. Kardashian has no idea what was in the bag. It says what he did with the bags and it says what--where he got them and where he left them off. And those are the questions that they are interested in and they are answered in the draft stipulation. If there is a question of whether this would be under oath, I don't think we would have a problem, once we agree to the facts, to put it under oath, if that is the question before the jury, to put "under penalty of perjury" at the bottom of it. I proposed it like we do it generally over in the federal Court, as a stipulation that I expected both parties to sign, that they stipulate that Mr. Kardashian, if called as a witness, would testify as follows: And then I proposed a certain amount of facts and I put then in the first person so it would read like testimony as well. But if there are suggestions as to the specific facts, I think that that is what we were going to be working on with Miss Lewis and Mr. Darden. If today is not a good day to do it, I am willing to come back.
THE COURT: Miss Lewis does make a good point, that she just received this, she should have the opportunity to sit down, go over it line by line, word by word, and then fill in the gaps where she thinks it needs to be flushed out somewhere. I think you are entitled--
MS. LEVINE: And I think Mr. Douglas wants that, too, your Honor.
THE COURT: What is a good date?
MS. LEVINE: If I might get my calendar, your Honor.
THE COURT: All right.
MS. LEWIS: And your Honor, of course I did not immediately inquire or ask Mr. Kardashian be placed under oath. The Court knows me well enough.
(Brief pause.)
MS. LEVINE: Perhaps if the Prosecution could even by telephone call or a conference call one evening or back here in Court if we could discuss it the beginning of next week, that would give them time, that would give the Defense team time to sit down and look at what we proposed and propose an alternative. Perhaps there could be an exchange of writings before then.
THE COURT: How about if I drag you both in Monday at 4:30?
MS. LEWIS: That is a good idea, your Honor.
THE COURT: It would be an off-the-record discussion so I don't need my Court reporter.
(Discussion held off the record between ms. Levine and Mr. Kardashian.)
MS. LEVINE: Mr. Kardashian is not available. I don't know if that is important to the Court.
THE COURT: Very important. He needs to be available to consult with counsel.
(Discussion held off the record between ms. Levine and Mr. Kardashian.)
THE COURT: Since he is counsel of record, don't I have the opportunity to order him to be here?
MR. KARDASHIAN: That's true.
MS. LEVINE: That's true, your Honor.
MS. LEWIS: Why don't we do it later this week so as to avoid any inconvenience. Today is only Tuesday. How about Thursday after Court?
MS. LEVINE: Or Friday.
THE COURT: How does Thursday sound? All right. Thursday at 4:30. All right. Okay. Anything else?
MS. LEVINE: Your Honor, if there is something that could be submitted by either party in writing, the afternoon by noon by fax to me that might be helpful to move us along as well.
MS. LEWIS: Your Honor, I have to make the obvious point that we don't know what the facts are. That is what the problem is, unlike counsel's Honor stipulation where we have some knowledge of the true facts independent of the Defense view so we can arrive at a stipulation.
THE COURT: I don't know if there is anything that you can corroborate, anybody else you can go out and interview as a result of what Mr. Kardashian says. I don't know. I would like to have you work it out first. If you can't, then we will have a hearing. Okay.
MS. LEWIS: Thank you, your Honor.
THE COURT: All right. We will be in recess.
(Brief pause.)
MR. MICHAELSON: Did your Honor have a chance to read it?
THE COURT: Nobody bothered to give me a copy.
MR. MICHAELSON: We did. I think it would be a good idea.
THE COURT: I have been busy.
MR. MICHAELSON: I know you have. If you have a chance.
(At 5:20 P.M. An adjournment was taken until, Wednesday, May 10, 1995, 9:00 A.M.)
SUPERIOR COURT OF THE STATE OF CALIFORNIA FOR THE COUNTY OF LOS ANGELES
Department no. 103 Hon. Lance A. Ito, Judge
The People of the State of California,)
plaintiff,)
vs. ) no. Ba097211 )
Orenthal James Simpson,)
Defendant.)
Reporter's transcript of proceedings Tuesday, May 9, 1995
Volume 142 Pages 26406 through 26693, inclusive
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APPEARANCES:
Janet M. Moxham, CSR #4588 Christine M. Olson, CSR #2378 official reporters
FOR THE PEOPLE: Gil Garcetti, District Attorney by: Marcia R. Clark, William W. Hodgman, Christopher A. Darden, Cheri A. Lewis, Rockne P. Harmon, George W. Clarke, Scott M. Gordon Lydia C. Bodin, Hank M. Goldberg, Alan Yochelson and Darrell S. Mavis, Brian R. Kelberg, and Kenneth E. Lynch, Deputies 18-000 Criminal Courts Building 210 West Temple Street Los Angeles, California 90012
FOR THE DEFENDANT: Robert L. Shapiro, Esquire Sara L. Caplan, Esquire 2121 Avenue of the Stars 19th floor Los Angeles, California 90067 Johnnie L. Cochran, Jr., Esquire by: Carl E. Douglas, Esquire Shawn Snider Chapman, Esquire 4929 Wilshire Boulevard Suite 1010 Los Angeles, California 90010 Gerald F. Uelmen, Esquire Robert Kardashian, Esquire Alan Dershowitz, Esquire F. Lee Bailey, Esquire Barry Scheck, Esquire Peter Neufeld, Esquire Robert D. Blasier, Esquire William C. Thompson, Esquire
ALSO PRESENT: Janet I. Levine, Esquire Alvin Michaelson, Esquire
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I N D E X
Index for volume 142 pages 26406 - 26693
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Day date session page vol.
Tuesday May 9, 1995 A.M. 26406 142 P.M. 26520 142
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LEGEND: Ms. Clark-mc Mr. Hodgman-h Mr. Darden d Mr. Kahn-k Mr. Goldberg-gb Mr. Gordon-g Mr. Shapiro-s Mr. Cochran-c Mr. Douglas-cd Mr. Bailey-b Mr. Uelmen-u Mr. Scheck-bs Mr. Neufeld-n
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CHRONOLOGICAL INDEX of witnesses
PEOPLE'S Witnesses direct cross redirect recross vol.
Cotton, Robin 142 (Resumed) 26416gc (Resumed) 26539gc
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ALPHABETICAL INDEX of witnesses
Witnesses direct cross redirect recross vol.
Cotton, Robin 142 (Resumed) 26416gc (Resumed) 26539gc
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EXHIBITS
PEOPLE'S for in exhibit identification evidence page vol. Page vol.
247 - Drawing by 26422 142 Dr. Cotton entitled "amplification"
248 - Large diagram 26431 142 Entitled "PCR analysis"
249 - Drawing by 26436 142 Dr. Cotton entitled "more amplification"
250 - Diagram depicting 26441 142 Two DNA ladders
251 - Drawing by 26444 142 Dr. Cotton entitled "PCR length difference"
252 - Diagram 26447 142 Entitled "more amplification"
253 - Plastic tray 26450 142
254 - Drawing by 26542 142 Dr. Cotton entitled "PCR controls"
255 - Drawing by 26611 142 Dr. Cotton entitled "population data"
256 - 17 autoradiographs 26542 142