All right. Thank you, ladies and gentlemen. Please be seated. Let the record reflect that we've now been rejoined by all the members of our jury panel, and Dr. Gerdes is on the witness stand undergoing direct examination by Mr. Scheck. And, Mr. Scheck, you may continue to the conclusion of the Court day.
Dr. Gerdes, let's return for a minute to 1306, the chelex bottle. Now, what role does chelex play in the DNA process? How do you use--how was it used at the Los Angeles Police Department and at other laboratories in the DNA testing process?
This is the first solution that you use in the process of extracting DNA from a specimen.
Uh-huh. And in terms of the amount that you take out of the bottle, does that have any relationship to the use of aliquots in terms of the way certain laboratories handle this kind of solution?
Yes. With this kind of solution where you use a very small amount of each item, you would tend to aliquot it into smaller volumes so that you don't go into that bottle a long time. The amount that's shown in this bottle is a six-month supply.
And why is it--why--if you went into the bottle many times in terms of contamination, does that have any consequences?
Yes. Every time you open the bottle, there's a chance of something falling in there. Every time you pipette or put a pipetter into that bottle, there's a chance of introducing something accidentally. So it goes back to the manipulation we talked about earlier. The more you manipulate things, the more you go in and out of them, the higher the risk. Every time you open, there's a risk and the more times you open it, the greater the risk.
Have you reviewed records in connection with the hybridization sheets from the Los Angeles Police Department as to lots of chelex? Have you done that?
Now, up here on this particular bottle, there is a no. 5. What does that represent?
Have you looked at lot numbers on the laboratory sheets with respect to the use of chelex at the lab?
The lot numbers are used, the same lot numbers recorded for DNA extractions over a period of months.
This is another reagent. This particular reagent called TE buffer is used to resuspend DNA.
All right. And, again, how much TE buffer is used in the course of running a DNA test?
Now, I'd like to show you Prosecution's 287 I believe entitled "PCR DNA typing, Los Angeles Police Department." Now, this first set of pictures under the title "Piper tech extraction," is that a picture of Mr. Yamauchi?
All right. Now, in terms of designing DNA laboratories using PCR, what importance is there in terms of structuring the flow of work from the point that the sample is first taken into the lab to the end of the process?
Well, in this process, you'll recall when you start with a small amount of DNA and after you've gone through the amplification process, you end up with a very large amount of DNA. So if you can make a one-way flow so that you always go from the smaller to the larger and never back, it reduces the risk of crossover of the high amount to the low amount which we talked about a number of times. But basically by designing the laboratory in such a way that you only have a one-way flow of low DNA concentration to high and never back, it's another procedure that's used by laboratories to try and reduce the risk of contamination.
So this first picture where it shows piper tech extraction, that takes place in the serology lab?
And the samples have come from that evidence processing room, the one where the garage goes up and down?
Now, the next picture down on the PCR DNA typing board shows pictures called "Preamplification, amplification, hybridization and photography"?
All right. Could you tell us where that is and how we get from piper tech at the extraction phase to the Parker Center for the amplification phase?
Well, Parker Center is actually located one to two miles from piper tech, a totally different building. So it's definitely separated. The amplification is set up in one room, the preamplification room. That's where the tubes and the reagents are all mixed together, and then it's amplified and hybridized in the second room.
All right. Now, after--when you do the amplification, is that where you produce the greater amounts of DNA that's sometimes called the amplicons?
All right. Now, the next step here in this board indicates that "Piper tech product gel, electrophoresis." And there's been testimony that--from Mr. Yamauchi that DNA samples are then taken back to piper tech into a room where they are then put on this PCR product gel?
Is bringing the amplicons or the PCR product back into piper tech consistent with the process of having a one-way work flow?
No, because, you see, you've gone from low DNA and right at this step, you've created high DNA by amplifying it, and this is at a different location, totally different building. But now they turn around and they go back to this building. So they're carrying back high levels of DNA into the area where there should be only low levels of DNA.
Are you familiar with the setup at the Department of Justice in terms of the flow of work?
Do you recall the testimony of Gary Sims with respect to stating that after amplification, that PCR product never leaves the amplification room in that laboratory?
Now, Dr. Gerdes, there's been substantial testimony in this case with respect to substrate controls that were used for the Bundy blood drops, LAPD items 47, 48, 49, 50 and 52.
All right. Now, first of all, let me ask you, were any substrate controls taken from the glove that--the Rockingham glove that Mr. Yamauchi analyzed on June 14th?
All right. So would it be fair to say that substrate controls cannot be used as a check against cross-contamination with respect to that glove?
Now, Dr. Gerdes, does the fact that testing of the Bundy blood drop substrate controls by LAPD, DOJ and Cellmark did not reveal the presence of DNA prove that there was no cross-contamination of these samples?
All right. Are you familiar with the testimony of Mr. Sims--of Mr. Yamauchi that substrate controls were typed?
Did you review the data and the testimony with respect to what happened to those substrate controls from the time that they first arrived to the laboratory according to Fung and Mazzola, what Mr. Yamauchi did with them, where they were sent and when to Cellmark and the Department of Justice?
Having reviewed the data on the substrate controls, do you believe that the fact that testing on--did testing on those reveal the presence of DNA?
Did you review the laboratory work concerning tests performed on the substrate controls at LAPD, the Department of Justice and Cellmark?
All right. Does the fact that the substrate controls appear clean prove in your mind that there was no cross-contamination of the samples 47, 48, 49, 50 and 52?
Well, there's a number of reasons. No. 1, as we mentioned earlier, in the NRC report and in my evaluation of the numerous runs at LAPD, it's not unusual to have that particular control not show a contaminant even though other items in that run had a contaminant. And you'll recall, we showed you that on the example of the 4 contamination earlier this morning.
In terms of the substrate controls, is there something known in molecular biology and analytical chemistry that's known as carrier or stabilizer?
When one is working with molecules in very small concentrations, very small amounts, if you do this in a laboratory, you need to store them in the presence of something called a carrier. If you don't store them in the presence of something called a carrier, you just--they tend to disappear. You lose them. Things when they're too small in amounts, they can stick to the sides of a bottle. There's unknown things in that solution that they're not quite stable. You just basically tend to lose it. So if you're looking at something analytically that's in a very small concentration, it's a standard practice that you add something called a carrier. In the case of DNA, what that would mean is you would add a non-human DNA to sort of stabilize the situation such as salmon sperm DNA, and that would stabilize very small amounts of DNA so that they wouldn't disappear.
If you would--Dr. Gerdes, let me ask you to assume that the swatches from samples 47, 48, 49, 50 and 52 were degraded by bacteria and that what was on those swatches was bacterial DNA. Do you have that in mind?
And that subsequent to that, those swatches and perhaps control swatches were contaminated with foreign DNA.
In terms of this carrier principal, what would the effect be in terms of the DNA that fell on the swatches with bacterial contamination as opposed to the blank swatches?
All right. Let's start with this hypothetical. Assume that you have a red swatch such as the ones used in this case and the DNA from blood on that swatch has been degraded and it's no longer human DNA, it's bacterial DNA.
Can that act in a way that's similar to the non-human DNA you were talking about as a carrier?
Dr. Gerdes, how--can you tell us more about your experience with using carrier non-human DNA and how that affects other DNA going onto that non-human DNA? How do you--what's your experience with that?
Well, one of the--you'll recall I talked about the fact that we talked--we work with this virus called cytomegalovirus. And it turns out that when we looked at that virus in transplant patients, since they're immunosuppressed, a significant percentage of those patients tend to shed that virus and it's present in their blood and you find it and in low levels. Now, the problem then became you're finding it too often. We need to identify which patient needs to be treated. So we developed a quantitative PCR, and for that quantitative PCR, I needed to develop standards that could be used as quantitative standards that were stable and could be run over and over so that I can measure the amount of CMV in the patient versus the standards. In the process of creating the standards, it became obvious that a carrier DNA was required to maintain the stability of those DNA's. Now, that's my personal experience with the specific incident. It's well known in other publications, other analytical procedures that this is a very common procedure.
Now, if you assume that the blood swatches in this case were degraded and consisted of bacterial DNA, could those--could that bacterial DNA act as a carrier?
And as a consequence, if you assume that bacterial DNA was acting as a carrier, would that account for cross-contamination being--showing up in greater amounts on the stained items that consisted of--under a hypothetical of bacterial DNA as opposed to the blank swatches?
Yes. That would explain it because on this the swatch that has nothing on it, there's no stabilizer. Therefore, you would lose the small amount of contaminant. On the swatch with the bacterial DNA, there is a stabilizer and, therefore, it would remain there.
All right. Now, you--are you familiar with Mr. Sims' testimony with respect to his view of the role that the substrate controls played as a check against cross-contamination?
Are you familiar with his answers to the questions, that as far as he was concerned, the substrate controls would have to run strictly in parallel with the other stained items to be a check against cross-contamination?
What do you understand that assumption of running in parallel to mean? What does it mean to you?
Well, again, the image of transferring from one item to the next by handling it, one control for that would be when you handle something with a large amount of DNA, the next item you handle has no DNA. So if that happened, you would pick it up there. And then the next item would have DNA and then the next item would have no DNA and then the next item would have and so forth. You alternate between a sample that has DNA or should have DNA and a sample that has no DNA. So that's what's meant by running them in parallel. It's more like in series really. You have to run--alternate a sample with DNA and a sample without DNA, and that should control for this cross-transfer.
Now, in your review of the way that the substrate controls were handled in this case, did you see evidence that they were not handled strictly in parallel in terms of how LAPD distributed them?
Well, these items at one point were sent to two other laboratories, Cellmark laboratories and Department of Justice. And this process of handling in parallel or in series, whichever you want to look at it, and as we described, that has to occur all the way from the very moment you start with an item till you get a result, and it doesn't matter what lab you do it in. It has to happen--it has to be sort of a chain of custody. It has to follow that flow at all times. When the LAPD mailed their specimens, the evidence items to both DOJ and to Cellmark, they failed to mail the controls, the substrate controls. To me, at that point, that has broken the chain of custody. The Department of Justice from the notes I have had to call to ask for specimens, the substrate specimens, and they didn't run them in parallel because they had to have packaged them at LAPD without handling the substrate control. If you think about it, if you're packing these things in a package and they're only mailing one, why would they handle it in parallel and then just not send the substrate control?
Overruled. But, Mr. Scheck, I'm not comfortable with the terminology of "Chain of custody" in this context.
--do you have familiarity--is the term "Chain of custody" used in terms of handling of evidence samples?
Well, in a paternity action, obviously it's another legal action. You need to have documentation of every individual who's handled a specific item.
And in terms of DNA laboratories generally, are rules set up for handling items of evidence to preserve their integrity for testing?
And have you reviewed protocols of forensic laboratories that talk about ways that samples ought to be handled to preserve the integrity of evidence?
Now, is it important in your judgment when implementing rules--and I'm asking you this now in your capacity as a DNA lab director. How many people have you supervised--how many people work in the IID laboratory?
All right. And right now, specifically under you, how many technicians do you supervise?
And in terms of training people to--technical people to go through with the DNA process, how important is it for them to know the purpose of the procedures they're following in terms of their use as controls?
How important is it to train personnel about the controls that they're using and why they're using them?
Well, protocols are there for a purpose and they need to be followed. That's how you standardize the testing result and that's how you guarantee it's a valid accurate result that can be relied upon. So it's important that they're trained in that protocol and that they follow that protocol.
All right. And incidentally, in terms of--for example, does that have application in terms of the use of gloves?
Yes. All aspects of how to handle the specimens and how to set up the testing and how to interpret the testing and so forth.
Well, is one as--is one purpose of wearing gloves to protect--the DNA laboratory to protect the handler?
Now, have you reviewed the testimony of Mr. Fung and Miss Mazzola with respect to their--what they knew about the purpose of the substrate controls?
All right. And--now, besides--so it would be fair--do you feel--withdrawn. So based on your review of the way samples were handled in terms of distributing them and the way they were--the review of the testimony here about how the substrate controls were handled, are you comfortable with the assumption that the substrate controls were run in parallel here?
Let me get back to it this way. In terms of the--in your review of the LAPD laboratory strips in terms of contamination, what is the significance of the degree of contamination you found in the extraction control versus the amplification control?
The significance is that it indicates that the area at which contamination is occurring in this laboratory is an early area, most likely in the DNA extraction or sample handling.
Now, besides your view that--about the substrate--your views about the substrate controls being handled in parallel, the fact that negative controls don't always clean negative controls don't always indicate contamination and the notion of "Carrier," do you have any evidence from review of the data that indicates that there was cross-contamination of DNA between samples handled by Mr. Yamauchi in this case?
And does this cross-contamination show up--does this evidence show up not just in the way samples were handled at LAPD, but how they were typed then subsequently at DOJ and Cellmark?
Now, Dr. Gerdes, are you familiar with the fact that on June 15th, 1994 at the evidence processing room and at the serology lab, Mr. Yamauchi handled item no. 12, blood drops recovered from the foyer of Mr. Simpson's home and the reference sample from Nicole Brown Simpson and the reference sample from Ronald Goldman?
Yeah. These indicate the typings for the three reference individuals, the DQ-Alpha and one locus, the GC locus of the polymarker gene system.
On the DQ-Alpha, there's a 1.1, 1.2 for Mr. Simpson, there's a 1.1, 1.1 for Nicole Brown Simpson and there's a 1.3, 4 for Ron Goldman.
And on the GC locus and the polymarker system, what are the types for these three individuals?
On the GC locus of the polymarker gene, it's a BC for Mr. Simpson and a C for Nicole Brown Simpson and an AA for Mr. Goldman.
Now, the next three boxes indicate something called "LAPD typing sheet," "Cellmark type sheets" and "DOJ type sheets"?
These are the recorded results that were found on the typing sheets of--on those dates when these specific references were typed.
Now, let's move first to June 15th, 1994 when Mr. Yamauchi did this initial typing. I take it he recorded for item no. 12, the blood drops found in the foyer, Mr. Simpson's genotype, 1.1, 1.2?
All right. Now, with respect to the reference sample, could you tell us what was recorded and also what you observed on the sheet?
Yes. There--it was recorded as a 1.1, 1.1, and on the actual typing, I can see a very faint 1.2.
Now, I think we have to do some exhibit marking here, your Honor. This--what are we up to as far as this board is concerned?
Now, this isn't showing up very well up on the screen, but there's a very faint 1.2 in this area (Indicating).
Up a little higher. If you look here (Indicating), there's a shadow, and if you look on the next strip, there isn't a shadow. It's very faint, but it's distinct and there's a 1.2 right there.
And, Dr. Gerdes, did you--have you reviewed typing sheets from the Department of Justice and strips and become familiar with their nomenclature with respect to traces, faint traces, very faint, hints, et cetera?
To the best of your ability, could you do us--could you write in under "NBS reference sample" and give your--using this black pen, could you write in the genotype that you see there and what--how you would characterize it?
Based on my understanding of the testimony from the Department of Justice, I think they would characterize this as a hint of a 1.2.
Your Honor, before that happens, I have an objection to that being marked on the board in its current form. I believe I raised that to the Court previously.
Now, with respect to Mr. Goldman's reference sample, the LAPD records there a 1.3, 4; and is the term very faint 1.1 what's on their record?
Okay. Make this 1308-C. Well, your Honor, may I--if you could, maybe the simplest way to do this is, could we go back--this was 1308-B I believe, this is the printout?
Could we make one printout where--put "NBS" by the arrow where you're indicating the 1.2, and let's put "RG" on the right-hand side so we can identify the strips. I'm talking about the right-hand side of the strip. That one, write "NBS," and below that we'll write "RG."
Now, in the DQ-Alpha system, when one has a--the 4 allele is showing and the--and there is a 1 allele there, does that mean--that means that that dot that we've indicated there--do you see in Mr. Goldman's sample there's a very dark dot that's 1.2, 1.3, 4; is that correct?
That's correct, because this particular dot will detect a 1.2, 1.3 or a 4. It's not specific for the 1.2 only. So if there's a 1 dot as well, then you have to count the possibility that there is a 1.2 there if there's a 1 dot and a 4.
Now, so in terms of Mr. Goldman's reference sample, what would that mean in terms of how you would call the existence of a 1.2?
Well, you'd have to consider the possibility at least that it masked and it might be there.
Okay. So from looking here at the LAPD typing sheet--now, with respect to item no. 12, is it your understanding, sir, that item no. 12 were--drops in Mr. Simpson's foyer that were the last blood drops collected on June 13?
And is it your understanding that these--that item no. 12 had sufficient DNA in it to get a strong band RFLP result at Cellmark?
Was the concentration of the DNA in item no. 12, certainly compared to the so-called Bundy blood drops, 47, 48, 49, 50 and 52, comparatively higher?
Well, do you know if Mr. Yamauchi handled item no. 12 in the same time and location that he handled the reference samples from Nicole Brown Simpson and Mr. Goldman on June 15th?
All right. Would these typing results be consistent--well, what are the--with a cross-contamination of item no. 12 with the two reference samples?
These results are consistent with cross-contamination of the 1.2 from item 12 into Nicole Brown Simpson and Ron Goldman's reference samples.
Now, what is the--in terms of the PCR process, what is "Competition"? What does that mean?
Well, if you're trying to amplify DNA from two contributors and there's a very large amount of one contributor and a small amount of the second contributor, the larger amount is going to tend to amplify faster and, therefore, it will often peak the small amount. So if they were to have fast ratios, something in high concentration with something in low concentration, most likely, the lower concentration contributor will have very weak signals.
So aren't the reference samples for Mr. Goldman and Miss Nicole Brown Simpson, wouldn't those be by definition high concentration?
That is one of those situations, as we mentioned earlier, where you have a 1 dot because of the 1.3 and then the 1.1 and now you can't determine. It could be either or. It might be DX. On the other hand, you can't really say that it isn't a contaminant either.
But what about the 1.2 dot on Nicole Brown Simpson's reference sample? Is that an artifact or contaminant?
That's a contaminant because the 1.2 doesn't have that kind of artifact. And if you see anything on there, that means there's DNA there.
KEY QUOTEAll right. Now, let's move to the next typing of reference samples of Nicole Brown Simpson and Mr. Goldman. That was done at Cellmark on August 5th, 1994?
All right. And what's written on Defense 1308, are those what Cellmark recorded on their typing sheets?
And first of all, were you able to observe or do you have a photograph of these strips?
I believe I do. Actually no, I don't. I have a Xerox is all I have with me of Cellmark's. No. I have the--
Now, with respect to--these strips represent both the DQ-Alpha and what other system?
All right. Now, what can you say about the C dots in your observation of the reference samples from Nicole Brown Simpson and Ronald Goldman?
The C dots which are specifically on the DQ-Alpha system, as you can see, are extremely light on all three references.
And in fact, I don't see any C there at all. But it is recorded on their typing sheet as being present.
Well, let's go through that. In other words, when you look at the actual photograph taken, you don't see a C dot?
But when they--when the typing strips were developed at Cellmark, an analyst wrote something down saying that they actually saw a C dot?
All right. Now, would you indicate here the faint--you don't even see a C dot on this?
And what's the significance of a light or non-visible C dot in terms of being able to see contaminants?
Well, the C dot is designed as an internal control of the system to tell you if you have enough DNA there. If you don't see a C dot, the user guide, the rules if you will, tell you that this is not an interpretable result. You can't count on that typing because there's too little DNA there.
But would it be a fair statement that the fainter the C dot, the less likely you are to see low level contaminants?
Absolutely, yes, because you're--the other way the C dot can be faint is either--the last step in this process is developed. It's just like you would develop film. You would watch this develop, and if you stop it too early, underdevelop it, then you won't see the C and you also won't see the light dots, other light dots that happen--that may have been there, they won't show up.
Now, could you please mark "Faint c" then? Would you charac--how would you characterize it? "Faint c" is what Cellmark put on its records?
Now, was there, however--what is the significance of the faint b recorded on the polymarker system for Nicole Brown Simpson?
Well, the significance of that is that is a second gene system, and you can cross-check one gene system with a second gene system and the--remember, Mr. Simpson has a BC and Nicole Brown Simpson has an ac. So the presence of a b here (Indicating) Is consistent with the b from Mr. Simpson finding its way into Nicole Brown Simpson and then not being detected until it gets to Cellmark where they use a second gene system.
All right. The b in terms of the polymarker system, is that a contaminant or an artifact?
Let's move on to the next time the reference samples were typed at the Department of Justice.
The Department of Justice recorded on Nicole Brown Simpson a 1.1, 1.1 with a faint trace 1.3 and a trace of 1.2.
All right. And given the rules of interpretation, what does that mean about a 1.2?
You would also have to consider the fact in this setup, that there might be a mask 1.2.
Would this data from the Department of Justice--well, let me start again. Is that 1.2 trace on Nicole Brown Simpson's reference sample, is that an artifact or contaminant?
All right. In your opinion, based on the principles of the DQ-Alpha system as you understand it, what does the appearance of that 1. Dot indicate?
In this case, again, that is known to have a cross-hybridization problem under certain circumstances, and the difficulty here is, we also have the 1 allele showing up again because of the 1.1 and, therefore, you can't really tell if this is an artifact or real.
And when you said under the circumstances where 1.3 is an artifact are what kind of circumstances?
With high level of DNA, which this may be because it's a reference sample and the fact that there's also the 1 dot showing.
Uh-huh. In your opinion, sir, does this pattern of typings from these three laboratories, is that consistent with evidence of cross-contamination of LAPD that was subsequently picked up and typings at Cellmark and DOJ?
My interpretation of this pattern is, it has two possible explanations. The first explanation is that there is cross-contamination of Mr. Simpson's blood into Nicole Brown Simpson or Ronald Goldman, which is then subsequently typed by the two laboratories that LAPD sent their specimens to. The second explanation is that there are possibly contaminants and artifacts that are found at LAPD that are also found at Cellmark and also found at DOJ, and those artifacts just happen to be consistent with the contamination of the cross-contamination pattern.
KEY QUOTESo in other words, there would have to be--at LAPD, with respect to Nicole Brown Simpson, that 1.2 would have to be LAPD contaminating it?
And then with respect to the Cellmark typing, the b would have to be an independent contamination at Cellmark?
All right. What would that b have to be--if this weren't your first explanation, that is cross-contamination at LAPD that was picked up at the other two labs, but a series of coincidental contaminations and artifact, what would that b in the polymarker have to be?
Well, what would the b in the polymarker system have to be if this were not cross-contamination that started at LAPD, but another explanation?
That b would have to be a contaminant that coincidentally is consistent with cross-contamination from Mr. Simpson to Nicole Brown Simpson.
And what about the DOJ typing? What about that 1.2? What would that have to be if this were not cross-contamination that started at LAPD?
That would have to be, again, coincidental appearance of the 1.2 that is consistent with cross-contamination from Mr. Simpson's blood into Nicole Brown Simpson's.
Oh, in Mr. Goldman's sample, it's the same answer. That's would have to be a DX or an artifact that's consistent with cross-contamination.
Thank you. Does that data, Dr. Gerdes--what effect does that data have on your view with respect to the efficacy of substrate controls that were used at LAPD in this case?
Objection. No foundation, calls for speculation, beyond the expertise of the witness.
It undermines my confidence in those controls since there is some evidence here that the cross-contamination occurred.
KEY QUOTENow, I would like to move on now to, did you--now, did you examine the data concerning typings made at the Los Angeles Police Department and the Department of Justice on samples that were collected from the Bronco console on June 14th?
So there was one set of samples collected on June 14th. Is that your understanding?
And then after that, it's your understanding what happened to that vehicle? Have you been following the testimony on that?
And you're aware of the fact that it was released to Viertel's tow yard without a special protection for "Biological evidence" box being checked?
All right. Now, I'd like to move to another--ask this be marked I think it's 1309.
And I'd like to mark a photograph and I--forgive me. I think that a copy of this photograph may have been introduced as a Prosecution exhibit, but I can't figure out which one it was.
My interpretation of this pattern is, it has two possible explanations. The first explanation is that there is cross-contamination of Mr. Simpson's blood into Nicole Brown Simpson or Ronald Goldman, which is then subsequently typed by the two laboratories that LAPD sent their specimens to.
It undermines my confidence in those controls since there is some evidence here that the cross-contamination occurred.
That's a contaminant because the 1.2 doesn't have that kind of artifact. And if you see anything on there, that means there's DNA there.
When the LAPD mailed their specimens, the evidence items to both DOJ and to Cellmark, they failed to mail the controls, the substrate controls. To me, at that point, that has broken the chain of custody.
On this the swatch that has nothing on it, there's no stabilizer. Therefore, you would lose the small amount of contaminant. On the swatch with the bacterial DNA, there is a stabilizer and, therefore, it would remain there.