Thank you. Good afternoon, ladies and gentlemen of the jury.
THE JURY: Good afternoon.
CROSS-EXAMINATION BY MR. SCHECK
Pleasure to see you. Mr. Sims, the socks you're aware in this case were first collected by the Los Angeles Police Department on June 13th?
And they were cut and tested by--for--with conventional serology by Greg Matheson on September 21st?
And the fingernail scrapings and clippings, items 84, you received from the Los Angeles Police Department after they'd been tested by Greg Matheson?
Well, I believe we received several sets from the Bronco. Is there a specific item number?
Well, set of items number in the 20's through 31, weren't those all collected on June 14th by Dennis Fung and Andrea Mazzola?
Just looking from your records of the labelings on the bindles and coin envelopes, you got one set of samples that indicated they were first collected on June 14th?
Right. Did you receive a set of samples that had notations on them indicating they were collected on June 14th from the Bronco?
I don't recall that being on the coin envelopes because I--no, I don't. I don't. Is there a specific item number? I'll look it up.
Let's try it this way, Mr. Sims. You received swatches from the Bronco that had LAPD item numbers in--with two digits?
All right. Then you received a second set that had three digits in terms of their item numbers in the 300's?
Okay. And do your notes reflect that those two sets of swatches were collected at different times?
And from examining the coin envelopes and bindles, are you aware that those were collected on July 3rd?
From your records, do you have information that the glove from Rockingham, the right-hand glove, item no. 9, was examined, handled and cut by Collin Yamauchi of the Los Angeles Police Department on June 14th?
All right. Did you see in the packaging from the glove an indication that Mr. Yamauchi had handled those on June 14th?
And on the coin envelopes that you received, there was a date associated with those items of June 13th?
Oh. With respect to the biological material that you tested on any of the items that you've testified here about today and the last few days, you do not know how any of the biological material got on those items, do you?
And you have no idea when the biological material got on those items, do you, from your own personal knowledge?
And there is no test that you can conduct on a specimen containing the biological material to tell you if it was there when it was--biological material was there when it was first collected or whether it got there through cross-contamination?
KEY QUOTENow, once a specimen like a swatch has been cross-contaminated such that the biological material on it, all right--withdrawn. Once a swatch has been cross-contaminated with biological material and it's received at your laboratory and you test it, you're going to get typing results that reflect the cross-contaminant?
All right. If you receive a swatch that contains biological material from a cross-contamination, if you do your job correctly and don't contaminate it yourself in the laboratory, you should get the--in your DNA typing results, the genotypes from the biological material of the cross-contaminant?
All right. If you do not do anything to contaminate the sample in your laboratory, when you perform a DNA test, you should get in your typing results the genotypes associated with that biological material that came from the cross-contamination?
If you had a sufficient biological material there to get a PCR typing result, you'd find it?
Now, if the cross-contaminant on that swatch after you tested it and did nothing to contaminate it were then given to a second laboratory, they should still get the same result you got assuming that they did not in their own laboratory analysis contaminate the sample?
And if we gave it to a fourth and a fifth laboratory, as long as there was still enough material to test, they should all get the same result?
Well, now you're assuming that the contamination would be uniform across, for example, a swatch.
So--and if one of those laboratories, let's say the second laboratory in were Dr. Blake's laboratory, he should get the same result you got?
Now, would you agree that in terms of multiple testing by laboratories, that the reliability of the testing is no stronger than the weakest link in that chain?
All right. And if a cross-contamination occurred to the Los Angeles Police Department for a specimen in this case, you tested it, then a series of subsequent labs tested it, that would not in any way rectify the first cross-contamination?
When you mention that kind of contamination, you're saying some kind of genomic DNA contamination?
All right. And when we're talking about genomic DNA contamination, so the jury understands, we're talking about a situation where one would get let's say blood from one source onto another specimen.
Well, it would have to be another bloodstain as opposed to like one of the substrate controls or--
Excuse me. Gentlemen, you need to allow Mr. Scheck to finish answering--excuse me--asking the question, and Mr. Scheck--
Okay. And that's to distinguish it from, you were talking about at the end of your examination, something called PCR carry-over contamination?
That's been what you've been doing in the various different laboratories where you've worked?
Only with regards to the application of population genetics, but I would not consider myself a population geneticist, no.
Uh-huh. You do not hold yourself out to this jury as an expert in statistics or biostatistics?
All right. You do not hold yourself out to this jury as an expert in clinical medicine?
You do not hold yourself out to this jury as an expert in the application of PCR base techniques to samples in clinical medicine?
By training and experience, your focus over the last decade has been the methods that a crime laboratory ought to use in handling forensic samples?
Well, I think the way you phrased that, there's a lot more to what I do than just what you mentioned.
Oh--well, I don't mean to--to--to limit it. In fact, you take great pride in being somebody that has expertise in methods that a crime laboratory ought to use when handling forensic specimens for purposes of conventional serology testing or forensic DNA testing?
Well, I--I--I think that hinges on, you saying I take pride in that, I guess I do take some pride in that, but that's not--that's not me.
Well, that is an area that you're holding yourself out to this jury as having expertise on?
Well, yes, I would agree to that. But you started by saying it's something I pride myself on, and--
Now, as an expert in crime laboratory procedures, you would agree, would you not, that there are certain factors which can create a risk of cross-contamination when handling forensic samples in a laboratory?
And that there are certain methods and precautions that ought to be followed to prevent cross-contamination?
I have a series of slides I would like to display to the jury and the witness. Could we call--should we call them collectively 1159, and then I'll do 1159-A, B and C?
I guess this is the departure point for our discussion, cross-contamination factors.
Mr. Sims, would you not agree that degradation of a crime scene specimen is an important factor to consider with respect to the issue of cross-contamination?
Well, degradation by itself is a factor in that if there's very little DNA there, one would have to be more worried about what could happen to that particular sample, that's true.
All right. And in this particular slide, in the box, red box no. 1, I'd ask you to regard that as a blood swatch containing the DNA of person no. 1 and then the arrow indicates a process of degradation where the biological material that would show up on a DNA typing test has been degraded to the point where it's not detectable.
All right. And a swatch such as the one on the right-hand side where the biological material has been degraded to the point where it is no longer detectable is the kind of sample that one should take great care in handling in a forensic laboratory?
Because when you have a degraded sample like that, the dangers and the risk of cross-contamination increases?
Okay. Now, another consideration in the question of cross-contamination is trying to separate those samples that have high DNA content from those that have low DNA content?
Because when one is handling samples that have a high DNA content and there's an inadvertent transfer to samples that have a low DNA content, cross-contamination can occur by accident?
Yes. That is a concern. In other words, that the high one could contaminate the low one.
Right. And so as much as you can, you would want to, in your practice in the crime laboratory, separate out those samples that have high DNA content from low DNA content when you've handling them?
Yeah--well, especially when you're doing the DNA extraction. That's where we are most concerned with that in our laboratory.
When blood swatches are wet--and now you're talking about a swatch that has a lot of DNA on it that's wet and a swatch that has a lot less DNA, and that's also wet?
Well, I think--I think at some point, you have to realize that you're--it's--it's--it's--it's like taking universal precautions. Sort of like when a hospital looks at blood samples, they assume every sample has aids. That's what's called universal precautions. And so you have to take what I would consider universal precautions whether you've got a swatch that has high or low because you don't know. You don't know the content.
This is the effort to separate samples that have high DNA content from low DNA content, is a precaution you try to follow in your laboratory?
Yes. But that's, particularly in our laboratory, when we're talking about DNA extraction. That's the main point there because that's when you turn this into a liquid sample.
When you're cut--you are actually handling and examining samples, don't you try to take reasonable care to divide up those samples that have high DNA content from low DNA content?
Well, for example, when I look at a garment that I might take a bloodstain from, that bloodstain may be a high level bloodstain. But then I would also, right next to it on the same garment, have a substrate control area that would be considered a low level. So when you're talking about examining items, I see that as different than when you're talking about extracting DNA. Those are two separate issues to me.
Would you not agree at the point where you cut a sample, that you should take precautions to separate items that have high DNA content and low DNA content?
Yes. At that level, I would agree with that. And what I tend to do is work on one item at a time so that they're separated in that manner.
And as you indicated, that when you then move from the point of cutting the samples to the point of processing or analyzing them, you also want to take special concern to separate samples that have high DNA content from those that have low DNA content?
The amplitype user guide is provided by the company that actually makes the PCR kits that are used in forensic science, and that user guide is usually provided to the students who take the course.
This is like a basic fundamental text on how to use, in this instance, PCR base techniques?
Although the discussion that we've having about separating samples of high and low content and degradation would apply to RFLP testing as well as PCR testing?
Well, it is more of a concern in PCR testing, I would say that. But yes, it's always a concern.
Are you saying that it's not a concern that you could get genomic DNA cross-contamination for purposes of RFLP testing?
Now, in that amplitype guide, is there not, the very beginning of it, a section indicating "special precautions"? Recall that?
And in that "special precautions," does not the kit indicate that performing DNA extractions from samples containing--
Do you recall any specific guidance given in the amplitype user guide with respect to separating samples containing high DNA content and low DNA content when performing extractions?
Well, is this a--the precautions listed in the amplitype user guide, be ones that you would rely upon as a forensic DNA analyst?
Well, I'd be careful about saying everything that's in there, but the bulk of that material, by all means.
All right. Would you rely--and I'm calling your attention to paragraph 1 and call your attention to the--I think it's just about the last sentence there that begins "perform DNA extractions from samples." is that a precaution that you would rely upon that's in the user guide?
--that one should perform DNA extraction from samples containing high levels of DNA, for example, whole blood, separately from samples containing a low level DNA, single hair, small bloodstains, et cetera, to minimize the potential for sample-to-sample contamination.
And when we're talking here about extraction, we're talking about that stage in the process where you take the little cuttings and you put them into these test tubes?
Would you take special care when examining the samples to try to examine them separately?
Well, I don't see how one could examine those samples how--you would have to do it separately. There's three different locations that I'm seeing. I see a little blue car and I see two little houses like monopoly.
--and assume one of those houses looks like Bundy and the other one looks like Rockingham.
All right? Now, wouldn't you agree that in terms of these little swatches that you get from different scenes, that just even in examining them, it would be good laboratory practice to examine them separately?
And wouldn't it be good laboratory process--practice when cutting these swatches to separate the swatches that you get from different scenes?
I--I think that again goes more to the extraction perhaps. That's--that's what I did in this case as much as possible; is I kept the Bronco samples by themselves, I kept the Bundy stuff by itself, I kept the Rockingham stuff by itself. The only time I violated that was the very first set of extraction--set of extractions when there was one Bundy drop and I think one Rockingham drop. But I think--I think as long as you're doing them one at a time when you're cutting them and then putting that sample away and making sure you have a clean surface, I think that's okay.
Right. Well, we'll get to what you do and cutting them one at a time and keeping clean surfaces. But just as a general practice, what you try to do as much as possible, even at the stage when you got the samples, was process the samples from the different scenes each separately?
And when samples first come into a crime laboratory and you're let's say cutting swatches, it would be good practice to make sure that you cut the swatches from one scene separately from those of another scene?
Well, again, I think as long as you work on them one at a time, that's okay. I don't think it's--it's bad practice necessarily to look at two swatches in a row as long as you clean up where you're working and you clean up your tools between each sample.
Well, we'll talk about cleaning and changing gloves and the rest of it. But let's just talk as a general practice, you try to keep the samples from different scenes separate?
Because--now, let's assume that one set of samples from one scene are severely degraded and another set of samples from another scene are not.
Wouldn't it heighten the risk of cross-contamination if you sampled those swatches from different scenes in the same time and in the same location?
Objection. Insufficient basis for that question, improper hypothetical, calls for speculation, it's argumentative.
I propose to ask a question in this form: If you had information that--one, that a suspect had indicated that one set of samples contained his blood and you were processing another set of samples whose origin was unknown, would you want to make sure that you separate it in examination, cutting of those samples?
Hold on. I was asking Mr. Scheck to be quiet while I heard your comment. Mr. Harmon.
Your Honor, I think there is. We know from the facts already that Detective Lange and Detective Vannatter had a conversation with Mr. Simpson at 1:39 in the afternoon where Mr. Simpson told them while at Rockingham the blood drops on the--trail on the Rockingham driveway were from him. Detective Lange indicated he had conversations about the evidence in this case with Mr. Matheson and Mr. Yamauchi and Mr. Fung the next morning, that Mr. Fung was made aware of this. And so what I want to do is just ask this question in limited form that doesn't bring out the statement just as a predicate for developing when additional witnesses come in. I think we already have a good faith basis for the record. I would just limit it that way so there's no implication about a statement, just information.
The form of the question is also somewhat argumentative. I mean we have the results. If they want to concede that these things were tested properly, then maybe we can stipulate to that. But, you know, it's the form of the question, "if you had information." he didn't have any information. He didn't encounter that. You're asking him to speculate what he would have done. He wasn't in that position.
Mr. Scheck, I appreciate your bringing this to the Court's attention because this is obviously a touchy area because it goes to statements made--allegedly made by the Defendant to the police detectives. The problem we have is, that statement is not before the jury at this time. I--in fact, I don't know to this day what Mr. Simpson is alleged to have said to the police detectives other than what I have inadvertently come across in the news media. But--
The issue is that I don't want to introduce it right now, but it's--what's important here for purposes of the DNA evidence--and it's a critical point--is that these police and laboratory technicians had knowledge that Mr. Simpson had said that the Rockingham drops were his, and they processed them at the same time as they did the unknown samples, creating a serious risk of cross-contamination. This is a critical point of our Defense as I'm sure everybody is well aware, one set being degraded and the other set, particularly item no. 12, which was picked up, the last series of swatches, from inside his house being far less degraded. So the point is, there's danger of cross-contamination. My formulation of this question in the hypothetical form only has to do with what good laboratory practices would be, and so I want to formulate the question in a way that is as neutral as possible in terms of drawing an implication. All I want to ask him is if he had information, he would have tried this. But I wanted to be super cautious; if you had information that one set of samples--all right--that a suspect had said one set of samples or had information that one set of samples came from a suspect and another were from an unknown origin, would you take special care to examine, process those separate. That is the question I want to ask him.
That's asked and answered. This might be--this might be okay next week when Collin Yamauchi testifies. I don't think there's a basis for asking him--
At this point, at this time, I'm going to sustain the objection. Okay. Off the record.
Mr. Sims, if you had one set of samples, blood swatches that were collected from bloodstains that came from inside a house on a clean wood surface--
--and they were collected between an hour and a half to two hours before the time that you began handling the swatches, examining and handling the swatches, okay?
Then you add another set of samples that had been collected seven hours before you got to the laboratory. All right?
Would you agree that, number one, the samples that came from those plastic bags that were collected seven hours earlier, there's a good chance that they would be more degraded than the swatches that had been collected three hours earlier from inside a home?
Well, in your opinion as a criminalist, would you regard one--the set of swatches that came out--that came off the substrates, put in the plastic bags, collected seven hours earlier, would you expect those to be more degraded than the samples that had been collected only three hours before you handled them that came off a clean wooden floor?
And those samples that came off the clean wooden floor had been put into plastic bags, if those were about an hour and a half, in that plastic bag for about an hour, hour and a half.
Okay. And then the question is, would I expect the ones on the sidewalk that had been packaged to be degraded?
Versus the ones that came off the clean floor that had been in the plastic bag for only an hour, an hour and a half?
Let's turn to--oh, well, before we do, and--and it would be a good precaution in the laboratory if those samples that I've described, one's in the plastic bag for seven hours off the dirtier substrate, one's in a plastic bag for an hour, hour and a half off the clean substrate, both came from different scenes, would be good laboratory practice not to examine and cut those in the same time--same time and the same place?
Wait. You guys are talking at the same time as well. Why don't you rephrase the question. It is vague as to when you say handled. I mean, do we mean processed them all at the same time? Separately? How?
All right. If you were to take those two sets of samples that we've discussed, all right?
--without regard to whether you handled one from one scene before or after handling one from the other, would that be a good laboratory practice that--withdrawn. If you handle them one from one scene, take them out of the plastic bags, putting them in test tubes, all right?
Then you took another one from another scene, took it out of the plastic bag, put it in a test tube, all right?
During the same period of time on the same work surface, without changing paper, without changing gloves, would that be a sound laboratory practice in your opinion?
You're on a work--you're taking these out of a plastic bag. You have a piece of paper on the table.
Plastic gloves. You take a test tube and you stick it into that plastic bag and get the wet swatches by manipulation into the test tube.
You take that from crime scene no. 1 that has the swatches that have been in the plastic bags for seven hours, okay?
Then without changing gloves, without changing the paper below, you move to the plastic bag containing the samples from the second scene.
Use the same method of taking the test tube, going into the plastic bag, all right?
There is no test that you can conduct on a specimen containing the biological material to tell you if it was there when it was first collected or whether it got there through cross-contamination.
Yes. As long as there was enough from the contamination to get a typing result.
These police and laboratory technicians had knowledge that Mr. Simpson had said that the Rockingham drops were his, and they processed them at the same time as they did the unknown samples, creating a serious risk of cross-contamination.
Yes. I think you would expect the ones from the sidewalk to be more degraded.
There are limitations to computer clip-art, Mr. Sims.