All right. Thank you, counsel. Mr. Harmon--excuse me. Mr. Sims, have you completed your writing?
Your Honor, I wanted the record to reflect that we have a patch to put over Cellmark's PCR calculations, a magnetic patch, because these will represent, as Mr. Sims described, a different calculation.
May the record reflect on exhibit 262, I'm putting a patch over Cellmark's PCR calculations to allow Mr. Sims an opportunity to present the cumulative calculations that he's just described.
Could you write up the cumulative calculations in the PCR markers between your laboratory and Cellmark? And then we'll clarify.
Now, your laboratory did the same--one of the same markers that Cellmark did, DQ-Alpha; is that correct?
So--and this is purely the cumulative frequency of the combined PCR test results between your laboratory and Cellmark on the Greg Matheson cut out from sock no. 13?
Okay. Would you write the more common frequency and then two, the less common frequency or at least the common frequency from among these three groups?
Okay. And you've got 1 in 50,000 to 1 in 6 million. What--what groups do those represent and then what is the other group? I guess we haven't explained that to the jury.
The 1 in 50,000 figure comes from the Caucasian data, the 1 in 6 million comes from the African American data, and then finally, I calculated an Hispanic figure, and that was 1 in 150,000.
Okay. Mr. Sims, why don't you stay up there. While you're there, we're going to go through the other sock stains starting with your number 42A on sock 13A in the leg area. What is the frequency for the DQ-Alpha D1S80 match which is consistent with the Defendant and the same three groups?
For the African American group, it would be about 1 in 570, for the Caucasian group, about 1 in 520 and for the Hispanic group, about 1 in 1400.
Okay. And would that frequency be the same for the next sock, 42-A(3) from sock 13A, the leg area? It's the same results. Would that be the same frequency?
And would the next stain produce the same results, would produce the same sort of frequency estimate?
Now, the next two stains, 42-B(1) and 42-B(2), produce the same results; is that correct?
And what is the--what is the range of frequencies, and describe the groups that those frequencies come from.
Okay. This would be for the DQ-Alpha type 1.1, 1.1 with the D1S80 type 18, 18. The frequencies would range as follows: I'll give the three groups. The African American calculation was 1 in 8900, the Hispanic calculation is 1 in 1300 and the Caucasian calculation is 1 in 990.
Okay. Could we move on to the Bundy photo board and the Bundy result board, photo board exhibit 165 and the Bundy result board, 259?
Mr. Sims, we're going to shift gears and talk about the combined PCR frequencies for several items that you discussed yesterday. Those are item 47--these are LAPD items. And the first four are from the Bundy walkway, 47, 48, 50 and 52; and then after that, we'll--I'll ask you to do your calculations for the combined frequencies between your lab and Cellmark on the three nail items from Nicole Brown. Okay?
Could we lower that down because we're going to start at the top? Is that okay, your Honor? And we'll move it up as we can.
Okay. Mr. Sims, let's start at the top, item no. 47 on the Bundy walkway, the first drop that you analyzed close by--closest to the victims. Did you calculate a combined frequency for Cellmark's poly-marker results and DQ-Alpha results which included Mr. Simpson as a possible source of that and your DQ-Alpha D1S80 results?
Okay. Could you express to the jury what the combined frequency based on those calcu--your calculations for the three groups that we've been using consistently here?
Yes. The figures are as follows: For the Caucasian group, it would be 1 in 1.8 million, for the African American group, 1 in 240,000, and for the Hispanic group, 1 in 2.2 million.
Okay. Your Honor, may the record reflect I'm going to put a cover over Robin Cotton's calculations?
And, Mr. Sims, why don't you write down, as we have, from the most common to the least common among the three groups that you've just described.
Okay. Why don't you put it up there and move on to 48. Okay. And 48, the results are the same as in 47, are they?
Would you write that on the patch and can we put the patch on the board, your Honor?
Wrong. No. That's right. I'm sorry. Item no. 50, that's another item that you and Cellmark both tested for the same PCR markers as 47 and 48? That's another Bundy walk stain?
Would you write that down on the patch, and when you're done, put the patch up on item no. 50?
Okay. We need a little patch on one of our patches, your Honor, if I could have a moment.
Okay. And would you look at the result chart. And item no. 52 is not a lot of space over there. The--did you produce the same PCR cross-lab multiplication for 52 that you produced for 50, 48 and 47?
Okay. And that doesn't change the RFLP result or estimate that Robin Cotton is working there, right?
I'll move on--if I can come back to that when we've got the patch ready, your Honor, I'll move on to items--the 84 group of items.
Mr. Sims, you've described to the jury the results of your testing and on items 84 of the three items yesterday from Nicole Brown's nail scrapings from both hands and nail clippings. Did you perform calculations for the combined frequencies of the results that Cellmark produced on that for their testing for poly-marker and DQ-Alpha which included Nicole Brown and then combine them with your D1S80 results?
And what are the results of your calculations? What are the frequency estimates for those three groups?
Excuse me. This would be, for now, the poly-marker--five poly-marker loci, DQ-Alpha and then D1S80.
And the results would be, for the Caucasian group, 1 in 50,000, for the African American group, 1 in 6 million, and for the Hispanic group, 1 in 150,000.
Okay. Okay. I'm handing you the patch for item 84A. Would you write down those combined frequencies and put them over in the right hand column?
And are these calculations the same for all three items, the scrapings from the left hand, the clippings from the right hand and the scrapings from the right hand?
Okay. Why don't I give you the three separate patches so you can put the number down all at the same time.
Okay. Can you place the patch over on 84A to the right over the--it's your DOJ DNA 46B. And then the other two patches are a little bit smaller. Would you put them over your 45-A(1)(B) from the right-hand clippings?
Okay. Mr. Sims, you can go back to your seat. Oh, no. We still have 52. Okay. Mr. Sims, we've got some patches on patches. Could you write down the PCR combined frequency for item 52, that drop out on the driveway, just the PCR testing that was done between DOJ and Cellmark on that stain?
Okay. Thanks, Mr. Sims. Mr. Sims, I'd like to shift gears if I can and talk about the possible effects of contamination on PCR versus RFLP. Okay?
You've already told us that you rely on the scientific literature regularly in forming opinions?
Well, I read a variety of them. In the forensic literature, I read the journal of forensic sciences, the journal of forensic science society, the American journal of human genetics. There's a variety of other journals that relate to DNA testing and also to the forensic use of DNA testing.
Well, the technology in--DNA technology is keeping--is evolving at a very incredible rate. It's--to me, it's much like computer technology. It's rapidly evolving. And what happens is, the advances that come about in molecular biology and genetics are then transferred to the forensic level. And so we're all evolving very rapidly.
Okay. I'm going--we're going to go through some of the articles, and I want to ask you initially whether you've read and relied upon them, which is the key word, in forming any of the opinions that you're about to express, okay?
Yes. I would like an offer of proof as to where this line of testimony is going, the articles that Mr. Harmon has just given me from Dr. Blake, and I would like to know the rulings in advance so that we can work out the groundrules about what can and cannot be said in this connection so that I don't have to get up and, you know, object continually. I would like to know what the rulings are in advance.
What are you guarding against? A constant implication that, is this the same Dr. Blake who was observing all this testing, that type of question?
Yes. We had an agreement that when he was beginning to get into this area, we would have a discussion about the perimeters of what could or could not be done.
Scientists rely on this. And while I understand their chagrin in trying to explain why he's off the witness list and why he's--and why he may not come in here, he's the leading scientist in this area.
Contamination issue, degradation. These are all simply addressed in these articles, and I think we're entitled--we're clearly entitled to have an expert rely on scientific literature and articulate the basis for his opinion and how he's relied on it.
And then I think 804 even makes it clearer, that while one may not appreciate--while they may try to trivialize his opinion is based on it, the fact is that he has based his opinion on scientific literature.
I have no objection to him saying he bases his opinion on scientific literature and expressing his opinion, going into all these details. But what I object to is that there are many authors to this article and continually mentioning this particular author to try to raise the implication that Dr. Blake approved of all the testing not in his laboratory--that's the issue in this case--but the LAPD. So I mean if he wants to elicit that there's other articles in the field and get into specifics, that's what I really want an offer of proof as to what he's going to bring out. You know, I have no problem with him saying he bases his opinion on all this and indicating what those articles are.
You know, the subject matter. I just think it's a 352 problem at the very least here to continually say, well, it's--
Mr. Harmon, what I'm going to tell you is off limits is this question, is this the same Dr. Blake who observed--
Okay. Mr. Sims, I'm going to read off the names and titles of several articles and ask you if you've read and considered them, and then we'll go through them in certain areas, okay?
Have you read an article by Comey and Budowle entitled validation studies on the analysis of the HLA DQ-Alpha locus using the polymerase chain reaction?
And Budowle is b-u-d-o-w-l-e? Have you also read and relied upon--and the subjects we'll be discussing soon--a chapter in a book entitled PCR technology, principles and applications for DNA amplification, Henry Erlich, editor, chapter 17, the title is applications of PCR to the analysis of biological evidence?
The authors are Cecelia Beroldingen, B-E-R-O-L-D-I-N-G-E-N, Edward Blake, Russell Higuchi, h-I-g-u-c-h-i, George Sensabaugh, s-e-n-s-a-b-a-u-g-h, and Henry Erlich?
Have you also read and relied upon an article in the journal of forensic science entitled polymerase chain reaction amplification and human leukocyte, L-E-U-K-O-C-Y-T-E, antigen oligonucleotide, O-L-I-G-O-N-U-C-L-E-O-T-I-D-E, typing on biological evidence samples casework experience?
It's--the authors are Edward Blake, Jennifer Mihalovich, M-I-H-A-L-O-V-I-C-H, Russ Higuchi, Shawn Walsh and Henry Erlich.
Have you also read and relied upon--and the testimony we'll be presenting soon--an article entitled analysis of genetic markers in forensic DNA samples using the polymerase chain reaction in analytical chemistry, 1991, the authors are Rebecca Reynolds, George Sensabaugh and Edward Blake.
Have you read and relied upon a chapter in forensic science handbook, volume 3, by Richard Safferstein, 1993, entitled DNA analysis in biological evidence: Applications of the polymerase chain reaction by George Sensabaugh and Edward Blake?
Have you also read and relied upon an article entitled or chapter entitled applications of the polymerase chain reaction in forensic science, the authors of which are Russell Higuchi and Edward Blake, and that's in the Vanbury report, no. 32?
Okay. Mr. Sims, are you--let's focus on PCR for a moment. Is it your opinion that a typing error in the PCR process is more likely to result in a false exclusion than an inclusion?
Okay. And have you read and considered and relied upon the casework article for that proposition?
Could you explain the basis for your opinion that a typing error in the PCR process is more likely to result in a false exclusion than an inclusion?
Yes. The basis for that is that if one obtains a result that is a false positive, then that sort of result would be more likely to say--to exclude somebody than to include somebody in most instances.
Could you be a little more descriptive of how that might occur during the PCR typing process?
Your Honor, I would object, that this is vague and without foundation at this point.
Well, for example, if one were to test a given bloodstain against a particular individual, particular individual may--his or her type may occur, say, in 1 in 10 or something like that, maybe 1 in 20 with a DQ-Alpha, for example. And so if you're generating at random wrong results, then it's unlikely that it would match that particular individual. It's more likely that it would match--the type would be--match somebody else.
Okay. Mr. Sims, is it your opinion that the application of PCR technology in the forensic context is in any way different than it is in the diagnostic context?
Mr. Sims, is it your opinion that any of the properties of forensic DNA samples are unique--or strike that. Is it your opinion that any of the properties of the kinds of forensic samples that your lab encounters are unique to forensic science or different than clinical setting?
Are you familiar in a general context with the kinds of--or have you read the casework article?
Okay. Would it help to refresh your recollection--is that discussed, the uniqueness or the difference of forensic samples, in the casework article, the lead author of which is Edward Blake?
Okay. Would it help to refresh your recollection if you reviewed--I can direct you to a page in that article, if you would.
Page 721. Can I show it to--be on page 721, if you would read the paragraph at the bottom.
No. No. The question is, does that refresh your recollection as to whether or not there's any correlation between the medical diagnostic application or the forensic application.
Yes. The point of this is that forensic samples may be mixtures. They may be degraded, but these kinds of samples are also encountered by clinical workers using PCR technology.
Objection. Move to strike this answer, this witness' answer about what's found in clinical technology.
And is your opinion based on having your recollection refreshed by reading the bottom of page 721 of Dr. Blake's casework article?
Well, I already had some opinion on that, but specifically with regards to the article, yes.
Okay. Now, just as an aside, have you read the NRC report that came out three years ago?
Have you relied on the NRC report in any way for any of the opinions you've expressed to this moment?
And do you intend to rely on the NRC report in any way for any of the opinions that you will express for the next several moments?
Could I have my book back? Could you define as best you can the term "contamination" in the crime scene forensic DNA context so the jury can appreciate the discussion we're going to have?
Yes. There are a variety of ways of looking at contamination. One would be fundamentally, for example, at a crime scene where you may have mixtures of bodily fluids, blood from two different individuals could land together, that sort of thing, or end up in a garment situation. That would be one form of contamination. Another form of contamination would be the concern one would have in the laboratory. In other words, if somebody is mishandling samples, then that could lead potentially to contamination as one DNA is transferred to another DNA. And then finally, the type of contamination that we are most worried about with PCR and that we have to take special precautions for is what is called PCR product contamination; and that's because this process of PCR, as Dr. Cotton explained, generates large numbers of these DNA segments that are of a particular short length that are considered to be PCR product now. And by generating those large numbers, you want to make sure that that material doesn't in any way contaminate your original source material or your extracted DNA.
And do you have an opinion about whether or not, generally speaking, there are adequate ways to control against those three areas of contamination?
I think it's--there's two responses here. One is that there are ways to control for the contamination. There are also ways of monitoring for that contamination. And both--both of those are important aspects with regards to contamination, both the monitoring as well as the precautions.
And I want to direct your attention to the chapter by Sensabaugh and Blake in the Safferstein article. Is the subject of those areas of contamination, which you've just described for the jury, is that discussed in that article?
Okay. Do you remember the entire discussion that occurs on pages 441 and 442 of that subject?
And so what is your opinion specifically about the kinds of controls that can safeguard against those forms of contamination?
Well, they basically--their words basically mirror the things that I was talking about where they--for example, they mention maintaining clean work areas, using gloves, changing gloves, that sort of thing. And then also, they stress which controls should be run. They--they draw an analogy to the types of precautions that would be taken in an infectious disease situation or laboratory handling infectious materials.
And do you have an opinion based on your review of that article that should contamination occur, it can be recognized?
I want to shift to another article that I've described earlier, PCR technology, chapter 17 by Beroldinger, Blake, Higuchi, Sensabaugh and Erlich. Do you have an opinion about whether or not the most likely avenue for chance introduction of foreign DNA is during sample preparation?
Okay. And do you have an opin--or is it your opinion that common sense precautions can safeguard against that?
And do you recall whether or not that subject is discussed in the article I just described, this chapter 17?
Okay. And do you agree that the presence of a contaminant is often readily apparent?
Is it also your opinion that appropriate controls should be used that would indicate these situations of contamination?
What opinion do you have if any about whether or not appropriate controls should be used that would indicate these situations of contamination?
The opinion I have is that those controls should be always be run to monitor for contamination.
And what opinion if any do you have about whether or not negative controls, including extraction reagent blanks and unstained substrate controls when possible, should be run for each batch of DNA isolations?
And what opinion do you have about whether or not the absence of a PCR product in these control reactions attest to the validity of the typing results derived from the evidence samples?
Do you have an opinion about whether or not it is desirable to have some form of redundant sample analysis in a given case?
And generally speaking, do you recall whether or not those subjects are discussed in chapter 17 that I've been referring to?
Do you remember whether or not those questions I just asked you specifically are addressed the way I reiter--the way I asked you?
I believe those are in there, but it would refresh my memory to be sure that they're in there.
This is really not an appropriate way to refresh someone's recollection. I don't believe it to be necessary at this point. Proceed.
KEY QUOTEMr. Sims, let's talk about the validation study that we discussed at the very beginning by Comey and Budowle.
Could--and I just want you to focus for a moment on the kind--was there a sample handling part of that study that's published and described in detail?
Yes. There was a--that was a major part of that article or an important part of that article.
Does it help you in deciding what safeguards to take against in-lab contamination or sample preparation contamination to rely on that?
And what is your opinion about sample-to-sample contamination in the laboratory? Is it possible for that to occur?
Okay. And the opinion you've expressed is actually based on where that was demonstrated in that article; is that correct?
Okay. What--let's just open it up. What kinds of samples were handled in that case and what sorts of conclusions were drawn from the possibilities of sample handling error?
Do you have an opinion about the kinds of sample handling errors that can occur that can allow samples to cross-contaminate one another?
Well, and also our own experience in the laboratory with PCR and the experience of many other people using PCR.
Okay. Let's focus on the article and what your opinion is based on having read the article. What sorts of sample handling errors is it your opinion can produce sample-to-sample contamination?
The sorts of concerns would be, for example, in that article, they mentioned two wet bloodstains being brought into contact with each other. That would be one example. There are other instances. They attempted to deliberately contaminate certain stains in those articles and they had difficulty doing that with bloodstains of sufficient quality and quantity of DNA. They also did some samples where they looked at saliva and blood and that sort of thing and how that might affect the contamination issue. I think the last thing they--or one of the other things they looked at was whether or not cutting with scissors, cutting a bloodstain, whether or not those scissors would transfer contamination.
Okay. Let's focus on--there's actually a table that describes--in the Comey article that describes their efforts to force samples to contaminate one another. Is that--
Okay. And from--based on having read that article alone, what sorts of sample-to-sample contamination were they able to induce?
As I recall, they were able to induce it when blood stains were brought into contact with each other, actually touching each other. They were able to induce it with mixtures of saliva and blood, for example.
Okay. Let's start--let's take those one at a time. When you say touching one another, are you referring to the dried stains that were stored together?
Well, I think they had a low level--detectable low level contaminant when dry. It was more of a problem when they're wet and touching each other, which one would obviously expect.
Would it help to refresh your recollection if you looked at page 1639 of the article?
Okay. And let's just talk about the--in that sample handling study, the two top categories, dried stains stored together and wet stains stored together.
Well, what they did was, they took--they took blood from two different sources, dried stains from two different sources and tried the--tested one, then tested the other to see which one may have contaminated the other. And with one of those, they saw no exchange. With the other one, they saw that there was a trace contaminant of one of the alleles onto the other stain.
I don't recall them actually mentioning the time. I think it just mentions that they were stored together.
And you mentioned also--give us a general idea of what sorts of other experiments, sample handling experiments the study was based on where they tried to force cross-contamination between samples that were ultimately typed using the PCR DQ-Alpha system.
Yes. For example, they looked at the effects of perspiration. They didn't find any contamination from that. They also looked at small one-microliter bloodstains that they were handling, and they did not find any contamination from that. They had a small one-microliter bloodstain that they coughed over for one minute, and that produced no contamination. And then--by that, I mean, they know the type of the bloodstain. They know the type of the cougher. And so they look to see whether or not the cougher's type ends up on the bloodstain. They also did an experiment where they took small one-microliter bloodstains and scratched their head for 30 seconds to shed their dandruff over it to see if that would cause a contamination problem, and it did not. Then they also did some experiments where they actually mixed blood and saliva, and there, as one would expect, you could get a contamination. You would see the types from the blood and the saliva.
Okay. I think you used the word "transfer" or "evidence transfer." what--or "trace transfer" in this discussion. What do you mean by that?
Well, what I'm talking about is whether or not small contributions of contamination would show up in a bloodstain.
And based on that study, the only two areas of trace transfer where wet stains stored together for some period of time--
Yes. The bloodstain was cut with scissors and the contamination was not detected. In other words, I--as I read the article, two stains in a row were--were cut with these scissors and the scissors, after cutting the first stain, the first stains type did not show up in the second.
Okay. Mr. Sims, let's shift a little bit here and let's talk about substrate controls in the context of the Comey article and in the context of the work that you did in this case. Okay?
Could you define a substrate control in the context of the kinds of samples that you typed in this case?
Yes. A substrate control--for example, if we talk about blood drops on the sidewalk, one would want to collect the bloodstain and then to collect and sample an area, an unstained area where there was no blood detected nearby the bloodstain. That's a substrate control. So you're testing that particular substrate and you're testing it very close to where the bloodstain is.
Yes. And then it goes through the entire process and you look to see if there's any type showing up in that substrate control.
Okay. And I believe a little while ago, relying on one of the Blake, Sensabaugh articles, you define three areas of sample cross-contamination?
I mentioned the contamination in the field. In other words, mixed samples occurring in the field. I mentioned contamination occurring in the laboratory as these samples are either processed or extracted, and then finally I mentioned PCR product contamination.
Okay. Let's talk about the field sample mix-up. And what I want to do is discuss the implications of having substrate controls collected systematically in the field. Okay?
And the question is, if--if a criminalist systematically alternated between substrate controls and stains in the evidence collection process, what effect if any does the presence or the availability of the substrate control have as a safeguard against sample mix-up?
It's an important safeguard because it shows to me--if the--if the substrate controls turn out to be negative, it shows to me that there is no cross-contamination from sample to sample. Because of the alternating structure of that collection process, one has a stain, then a substrate control that should turn up negative, then another stain, then another substrate control. So that monitors that between each one of those stains, you've got one of these substrate controls. And if that shows negative, then that indicates that you're unlikely to have contaminated the bloodstains on either side of that control.
Okay. What effect--let's focus on the same context as the safeguard against sample mix-up in the field. What effect does just simply collecting one stain at a time with its substrate control have as a safeguard against sample mix-up in the field?
Yes. I think that's an important safeguard because it means you're focused on one particular event and you're not likely then to be handling too many samples at once. You're just keeping track of one item at a time.
Okay. Let's move to the next category that you described, and that is contamination by investigators or laboratory personnel.
Okay? What effect does the presence of substrate controls which type clean, do not produce a type, have as a safeguard against contamination by investigators or laboratory personnel?
Well, those are very important because you have to remember that if those are negative, in other words, they have no DNA, they're even more vulnerable to this contamination showing up than would a good bloodstain be. In other words, a good bloodstain be--a good bloodstain might have so much DNA that you may not even see a trace amount of contamination with this PCR testing. But these substrate controls, if they're negative to begin with, they have no DNA, they're certainly going to be more vulnerable to showing any traces of contamination. So that's why they're important.
Mr. Harmon, we need to take our break at this point. All right. Ladies and gentlemen, please remember all of my admonitions to you; do not discuss this case amongst yourselves, don't form any opinions about the case, do not 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 be in recess for 15.
That would be very wrong.
For the Caucasian group, it would be 1 in 1.8 million, for the African American group, 1 in 240,000, and for the Hispanic group, 1 in 2.2 million.
If one obtains a result that is a false positive, then that sort of result would be more likely to say--to exclude somebody than to include somebody in most instances.
As all of the ones that we tested were negative, yes.
This is really not an appropriate way to refresh someone's recollection. I don't believe it to be necessary at this point. Proceed.