All right. Thank you, ladies and gentlemen. Please be seated. Let the record reflect that we have been rejoined by all the members of our jury panel. Good morning, ladies and gentlemen.
THE JURY: Good morning.
Dr. Gerdes, would you resume the witness stand, please.
John Gerdes, the witness on the stand at the time of the evening adjournment, resumed the stand and testified further as follows:
All right. The record should reflect that Dr. John Gerdes is on the witness stand undergoing cross-examination by Mr. Clarke. Good morning again, doctor.
Doctor, you are reminded, sir, you are still under oath. And Mr. Clarke, you may conclude your cross-examination.
Thank you, your Honor. Good morning, ladies and gentlemen.
THE JURY: Good morning.
CROSS-EXAMINATION (RESUMED) BY MR. CLARKE
Dr. Gerdes, do you recall testifying last week that at the LAPD laboratory where DNA extraction is done that the laboratory does not use a laminar flow hood?
All right. Your Honor, with the Court's permission I would like to display to the witness exhibit 1301 which is a photograph of the laboratory.
And in particular, with respect to this photograph, does this photo show the hood that you described during your testimony in the DNA lab at the LAPD?
Now, as far as your tour of the laboratory back in December, did you make notes during that tour?
And in fact did you create rough, let's say, diagrams of various locations at the DNA laboratory at the Los Angeles Police Department?
In terms of your keeping those notes, did you attempt to be as accurate as possible, setting aside exact scale?
Yeah. There was no scale and it was just to give me a rough idea so that I could go back to those and recall what I had seen.
Now, did you have occasion to provide to the People last Friday notes that you took, including a diagram or diagrams of this particular tour?
Yes MR. CLARKE: All right. Your Honor, I would ask to have marked as People's next in order, a single page, which I'm showing to counsel.
Dr. Gerdes, showing you People's exhibit 569, does that appear to be a Xerox copy of one of your notes?
And is that in fact the note that contains a rough sketch or rough diagram of the extraction area at the Los Angeles Police Department?
Does this appear to be a--well, the lower portion of that single page of notes, People's exhibit 569?
And this is your rough sketch or rough diagram of the DNA extraction area at the LAPD?
Now, there appears to be a fairly long rectangle, comparatively speaking, in the middle of the diagram which is--I'm not sure I can really read it, but it looks like it has two words; is that right?
All right. Off to the left of that long rectangle towards the top there appears to be a square with the term "Hood" written inside?
Now, off to the left of that, what are the other to words that precede the word "Hood"?
Well, at that time I hadn't really noticed that this wasn't a laminar flow hood. I put down "Laminar flow" and I didn't really realize until the second visit that this wasn't a laminar flow hood.
KEY QUOTEUpon your initial visit to the Los Angeles Police Department you put down "Lam flow hood" to describe that particular hood?
Now, Dr. Gerdes, you testified last week that your DQ-Alpha PCR typing is not ready for forensic testing, correct?
Until adequate controls are incorporated to control the contamination problem, that continues to be my opinion.
And it is your opinion that it should be used for either including potential donors of DNA or excluding?
Okay. Without getting into great detail, does that method involved, after amplifying a sample, basically looking at the pieces of DNA information, these liters, A's, T's, G's and C's one by one?
You referred last week to a number of scientific publications discussing DQ-Alpha as, and I think you used the term "Demonstration papers"?
Now, you have testified for approximately the last five years that PCR DQ-Alpha typing should not be used in forensics, correct?
I've been very consistent in expressing my opinions about contamination and my concerns, yes.
You have actually come to courtrooms like this and testified the same way as far as that particular opinion?
As far as your own laboratory, is it correct that most of the methods that you use in your lab in Denver are methods that don't involve the use of kits?
You mentioned chlymadia. That is one of the tests for a sexually transmitted disease that you use a kit that is actually manufactured by Roche, correct?
Well, there is the vast majority of the testing our laboratory does; testing for antibodies for HIV, THLV, I can go on and on. It is probably a page-long list of things, most of which we do use FDA-approved kits.
Are any of these kits manufactured--well, let me rephrase. Were any of these kits developed in your own laboratory?
Is it then your testimony that most of your methods--well, let me strike that. Rephrase that if I may, your Honor. As far as a grant proposal that you described during your direct examination, do you recall that testimony?
That related to a particular technique developed in your laboratory; is that right?
It hasn't been developed yet. That is what the grant is for. We are proposing to develop that technology.
So the grant is basically your receiving, your laboratory, receiving money to develop a particular technique?
As far as that grant, does this process involve your laboratory submitting a proposal to a government agency?
And then the government--I'm sorry. And the government agency then uses that proposal to decide whether or not to grant your laboratory money to look at this proposed technique?
As part of that proposal are you required to describe a number of different things in this application for money?
As well as information about the individuals who would be involved in developing this technique?
You wrote the entire document? All right. Isn't it true that in that document you state, in reference to your laboratory: "Most of our testing could be described as home-brewed as opposed to commercial kits."
That statement that I just read, was that a statement that you wrote in that proposal?
Yes. It refers to the fact that in our laboratory we do go through some research and development and then it is progressed onto testing that is routine, and it has to do with our research and development department. It has nothing to do with the testing menu that we offer at the present time, which is what you asked me initially.
Well, is it then correct that most of the testing methods in your laboratory are, quote, home-brewed?
Most of the newer methods. This is talking about the next generation, if you will, from our laboratory. Most of what we do at the present time are kits that are FDA approved. What we hope to do is to move into the field of development of new diagnostic technologies, and we have been involved in that process over the--since I have been hired. That is one of my jobs. But we are not yet using those types of testing for routine testing.
It simply means that you are developing the test yourself, as opposed to buying a kit.
That would be the only one for DNA. All of the kits that we use, other than that particular kit, involve serological methods.
Now, as far as degraded samples, Dr. Gerdes, and we spoke about that last week, your concern about the reliability of results obtained using PCR-based testing in forensics is based really on the nature of the specimen? In other words, the fact that it is a bloodstain that may have been on a sidewalk as opposed to blood removed from a patient in a hospital; is that correct?
Now, as far as this use of DQ-Alpha testing, are you familiar with its use on cases in which defendants have been, for instance, in prison for a number of years?
And in fact DQ-Alpha testing has been used to determine years later that a person may have been innocent of a crime; is that correct?
And in fact inmates have been released from prison as a result of the--I'm sorry--as a result of typing results obtained by using this PCR DQ-Alpha method?
Your concerns about degraded samples would apply equally to those cases as well; isn't that true, where the samples may be years old?
Is it your view that in those--under those circumstances that inmates should not be released from prison as a result of DQ-Alpha typing conducted what may be years later?
I think you have to take every case by case in terms of how much weight to put on that or whatever, but my position has always been consistent that until you have more adequate controls, and in specific in those kind of samples where they are old, degraded and in small quantities, this technology has a tremendous risk of error.
As far as the samples that were not amplified and typed at the Los Angeles department--and I asked you a number of questions of about that last week, correct?
Sure. As far as the samples that were not amplified and typed, in other words, they weren't subjected to this PCR process and typed at the LAPD, do you recall that?
Isn't it true that independent laboratories who reach the same results adds confidence to the results themselves? In other words, the layer or level of confidence that an analyst can have in the accuracy of those results?
It will give you confidence from that step on, but what happens in the previous steps can't be cross-checked.
Isn't it correct, Dr. Gerdes, that if you work in two separate labs and try and come up independently with the same result, then that is always going to be a confirmation of the test and give you more reliability?
Only if neither--both labs handled totally those specimens independently. That means they are collected and sent, as we have described earlier in the clinical situation, to both labs and are never exposed one lab to the other.
Of--I may have, but that was prior to more recent cases where it has become more and more obvious that there are problems early on.
Samples 48, 50 and 52, the bloodstains at Bundy, were swatches sent to different laboratories, correct?
As far as Cellmark is concerned--and I would like to shift your attention to known samples or if we use the term "Reference samples," can that indicate, as far as these questions, we are talking about known samples from the people who may be involved in a case, all right?
Isn't it correct that when Cellmark conducted its testing on the known samples they were done blindly?
They were given a code number when they arrived at the laboratory and then the technician would type it from there.
In addition to having a code number, isn't it correct that the actual known reference samples weren't labeled for Cellmark's purposes as to who of the three people they came from?
I don't recall if that is the case. I believe--I know they were labeled with a code name, but I'm not sure if they will have the information as to who they he were from. I would have to double-check.
All right. Do you have information at your hand would be able--I'm sorry--help you answer that question?
That appears to be correct. They were labeled with a code name and it doesn't have who it is next to it.
So Cellmark was in fact given these known samples and they were coded C-1, C-2 and C-3, weren't they?
Isn't it also correct that as far as the DQ-Alpha types that the Department of Justice typed that those reference samples were done after most of the evidence was typed?
And in fact isn't it true that the known samples were not typed until after there were PCR results on several of the Bundy blood drops at the Department of Justice?
After several of the stains from the Bronco were tested by the Department of Justice?
Those reference samples were typed, after, for instance, one of the blood trail at Rockingham was typed, one of those drops also?
In your view is that also an important step to take, to type those reference samples after evidence is typed?
Now, I would like to return, if I could, Dr. Gerdes, to the fact that in your laboratory you develop methods for use in DNA typing in your lab, correct?
Part of your function at the laboratory--and I believe you said you are director of the research and development arm of the lab?
And in that role, as far as the research and development role of the laboratory, you try to develop methods that other laboratories can use, correct?
And in fact your proposal for a grant is one such proposal, to develop a specific technique to type DNA that other laboratories can use?
You want to make sure that your techniques operate properly before they are used, for instance, in clinical case work?
You also want to be able to market or sell these methods as quickly as possible; isn't that correct?
Is your laboratory committed to rapidly implementing DNA technology to diagnostic testing?
And in fact you want to get these new techniques out there and marketed as soon as possible, correct?
We have a projection as to how long this will take. The technology we are describing is so new it is going to take three to five years before we even confirm the technology itself, but we are really not talking about marketing for that many years.
Well, Dr. Gerdes, isn't it true that your laboratory is committed to getting these newly developed techniques into the clinical laboratory as quickly as possible?
And in fact that is what you told the United States government as far as your grant proposal, didn't you?
As far as--we've talked about PCR as one technique. There is also the technique of RFLP that you have discussed in your direct examination, correct?
Can we call those different methods or methodologies? What word would you feel comfortable with to describe that there are two different techniques?
Isn't it correct that a consistency in result, that is a result is giving the same answer from both PCR testing as well as RFLP testing on the same sample, is one measure of the accuracy of the PCR technique?
It does tell you some information. The RFLP is a more discriminating test, so you would expect that there would be a number of occasions where the PCR would include someone and RFLP would exclude them.
Okay. And that is certainly one characteristic of RFLP typing, that it is more powerful in telling people apart, correct?
If you saw PCR results that, for instance, exclude someone and from the same sample an RFLP included the person, that would give you great pause for concern about PCR typing, wouldn't it?
Not necessarily. It depends on how many probes and in any genetic analysis you look at multiple markers, and once you find an exclusion, if it is confirmed, especially, then you have to believe that.
Well, let's make it more specific. Let's say that on a particular sample you saw a five-probe RFLP match. That would be powerful evidence of who that sample came from, wouldn't it?
If you saw a PCR result on the same sample that revealed results that excluded that person, wouldn't that give you concern about the PCR result?
So therefore if there is consistency between the RFLP results and PCR results, doesn't that give you greater confidence in the PCR results?
Well, haven't you testified previously, Dr. Gerdes, that you have no problem with the RFLP technology?
And you have testified in this case that you have no problem with several of the RFLP matches in this case; isn't that true?
Isn't it in fact the case that if there is an RFLP match on a sample, in your opinion that validates the PCR result on that sample?
Isn't it true that if there is an RFLP match on the same sample that a PCR result is obtained, that that RFLP match confirms the PCR result on that sample?
Of course you have to look at the sample. Even in RFLP there are going to be circumstances where those kind of results need to be looked at with suspicion in terms of whether it is a mixed sample and the same sorts of issues that we discussed earlier in general in terms of DNA technology and forensics, so you can't make a broad blanket general statement like that. You need to look at the circumstances for each item even in an RFLP test.
Dr. Gerdes, haven't you previously testified that if you get a PCR result on a sample and you already have an RFLP result on that sample, that that RFLP result confirms the PCR result?
Assuming there are no difficulties or suspicions about the nature of the sample or mixtures or other complications like that.
Isn't it true, doctor, that if you cross-check the PCR results and RFLP results on enough samples in a given case that that is a significant method of validation?
And in fact those words that you used were just as I stated to you, were they not, that if you cross-check the PCR results and RFLP results in a given case on enough samples that that is in fact a significant method of validating the accuracy of the PCR results?
I probably said that, but you have to look at the context around that. I'm sure I also said that you have to look at the sample and the things that I've talked about here.
KEY QUOTEDr. Gerdes, didn't you in fact testify to what I just read to you less than one year ago?
Your Honor, I think that we have--should have an opportunity to see what he is referring to. We thought those were the rules.
Overruled at this point, but if you are going to confront him with some specifics, we need to see it.
Do you recall testifying in a case involving a Defendant named McIntosh in the state of California?
Isn't it correct that in that case you testified to the fact that if there is this cross-check on enough samples that that is a significant method of validation?
Dr. Gerdes, with regard to this McIntosh case, didn't you testify in that case under a year ago?
Isn't it in that case that you made the specific comments that I just read to you?
Your Honor, I'm going to move to strike unless he can show the specific reference.
It depends on the samples. We need to--again, you know, all of these are significant in terms of the number of matches, but you have to, of course, take into consideration the nature of the sample, whether there is a mixture or not. There are other things that complicate this issue. I can't just give you a blanket statement that that many probes is significant unless I know the nature of the samples and whether they are mixtures and those sorts of issues.
If you see a sample that is a 6-probe match that is showing either one or two bands that clearly match the one or two bands that an individual has, that is a significant match, isn't it?
Whether it is eight or fourteen, if six is significant, anything more is significant; is that right?
As far as this case did you examine the RFLP results obtained by the laboratories in this case?
Isn't it correct, Dr. Gerdes, that as far as the RFLP and PCR results in this case that the RFLP results confirm the PCR results in this case?
Have you seen a case with more RFLP matches in your history of consulting with criminal defendants?
Your Honor, at this time I have a board that I would like to be marked as People's next in order.
Now, Dr. Gerdes, I would like to show you what has been marked People's exhibit 570, I believe.
And then there appear to be a number of different samples listed on the far left; is that right?
And then across on the right are columns entitled basically which laboratory produced the result?
And then lastly, individuals who are not excluded from those particular samples as having been the donors of the DNA; is that right?
Now, turning your attention first, there appear to be four samples from LAPD item no. 9, the glove; is that correct?
And on those--and let's start with the first sample and can we use G1? Is that a way of telling the four samples apart?
That sample revealed results from the Department of Justice after testing at five RFLP probes, correct?
And those results excluded, that is, indicated a mixture of Nicole Brown and Ronald Goldman, correct?
Incidentally, when you use the term, what does a significant match mean? I'm not sure that question was clear. Let me rephrase it. As far as a 5-probe match or a 6-probe match and so on being a significant match, what does the term "Significant" mean in that context to you?
Umm, as you know, there is a controversy as to how--you know, what level of significance there is, but in my opinion five probes would be certainly very significant in terms of putting some weight as to that match.
And in fact in your opinion that would be strong evidence that in fact a sample that matches at five probes came from a particular individual who matches that sample?
Again, it is controversial and I am not a population biologist, I am not involved in that controversy, but that is--it would be, in my opinion, significant.
When you perform a paternity analysis how many probes do you routinely use in determining whether or not a father is the father of a child?
Paternity you are comparing apples and oranges. It is different statistics, it is done in an entirely different way, so it is really not a good comparison, but we do use five probes.
All right. Turning to G2, those results reflected a 5-probe RFLP match to both Nicole Brown and Ronald Goldman, correct?
And then lastly on the gloved area, G4, the results showed a 5-probe RFLP match to both Ronald Goldman and Nicole Brown, correct?
Turning to the Rockingham foyer, item no. 12, Cellmark produced a 5-probe match to Mr. Simpson using RFLP, correct?
You don't have any criticism of the accuracy of the results obtained by Cellmark, correct?
Turning to the sock, in fact there were a total of, and let's start with the ankle area, both the Department of Justice and Cellmark tested the ankle area of the sock using RFLP, correct?
That testing revealed at the Department of Justice an 11-probe match to Nicole Brown, correct?
Cellmark also probed staining from that same sample at five probes; is that right?
If two of the probes used by Cellmark and DOJ were the same, would it then be a 14-probe match in reality?
Turning to the Bundy walkway, item no. 52, Cellmark produced a 5-probe match with Mr. Simpson, correct?
And in fact that data correctly reveals a 5-probe match with Mr. Simpson, correct?
In this particular item there is very little DNA and in this particular item I disagree with that.
Is it your opinion that Dr. Cotton was incorrect when she concluded that that match existed with regard to Mr. Simpson?
She is not incorrect in concluding the match, but the source of the DNA here is what the issue is. That is where the question is. There is very little DNA. It is down at the level of DNA where cross-contamination could be the explanation and the circumstances under which that particular item was handled makes that a distinction possibility.
Dr. Gerdes, is it your testimony that the RFLP results on item no. 52 came from contamination?
And in fact is it your opinion to a reasonable scientific certainty that item 52 revealed DNA that was not from the donor of the bloodstain but in fact came from another source?
You are not offering an opinion that it came, but you are raising the possibility; is that correct?
Turning to item no. 78, the drop that revealed a 5-probe match to Nicole Brown and Ronald Goldman, correct?
And then lastly on this board, referring to item no. 117, the Bundy rear gate, first of all, how many probes--there doesn't appear to be anything written in under "RFLP results," correct?
Until I look that up I don't know exactly how many probes there were on that particular item.
Your testimony has revealed you have no criticism of that match to Mr. Simpson; is that correct?
Incidentally, Dr. Gerdes, you are not familiar with the fact that there were serology tests conducted on many of these evidence items, correct?
I'm not familiar with the--I have not seen the reports. I am familiar that they were done, but I'm not familiar with the specifics.
Isn't it true that if the serology results confirmed--well, let me rephrase. Isn't it true that if the serology results were consistent with the PCR results that serology would be another methodology that the accuracy of the PCR results can be cross-checked against?
Do you utilize serology to confirm the accuracy of any of the results in your own laboratory?
It is the other way around. We have serological tests where we may do PCR to confirm that.
It would be much harder to cross-contaminate a sample and obtain serological results than it would a PCR result, correct?
In other words, cross-contamination isn't the same concern with serologic techniques because they are not as sensitive as PCR is to detect small amounts?
It depends--you have to look at the specific test and so forth, but in general that is true.
As far as cross-checking by these different techniques, PCR and RFLP, isn't it true that additional markers beyond DQ-Alpha, such as polymarker, the five polymarkers and D1S80, give the analyst an opportunity to cross-check the accuracy of results even more?
Again, you have to talk about the specifics and in the polymarker system there is a 2-probe--in most cases there are two allele systems. You know, two of them are three-allele and the rest are two-allele systems, and if you are dealing with mixtures, such as a contaminant would introduce, it is frequently not informative because you have only two, you have an a and a B, and if you have both, then that includes everybody, so it is not quite as informative as DQ-Alpha being able to look at the possibility of additional human DNA being there.
In other words, as to the polymarkers, they don't have a lot of different variations, correct?
But they can present very informative results when you look at many of them, such as the five?
And in fact it has more variations or different possible types than the five polymarkers?
Your Honor, I would like, with the Court's permission, to use People's exhibit 259, the Bundy results board.
Now, Dr. Gerdes, have you had an opportunity to see either this board or a board containing similar information?
All right. And I would like to start, if I could, with what is labeled at the top "Item no. 47, first drop by victims."
And how many different genetic markers produced a result consistent with Mr. Simpson?
Turning your attention to item 48, how many genetic markers produced a result on that particular item from the Bundy walkway that were consistent with Mr. Simpson?
Turning now to item 49, how many genetic markers produced that result using PCR consistent with Mr. Simpson?
Turning to item no. 50, how many PCR-based genetic markers produced that sample result consistent with Mr. Simpson?
Is it then the case that item 52 matched Mr. Simpson at twelve different genetic markers?
Dr. Gerdes, isn't it correct that item no. 52, the Bundy blood drop, matched Mr. Simpson at twelve different genetic markers?
KEY QUOTEItem no. 56--and first of all, let me return for a moment, if I can, to 47 through 52. Isn't it correct that the PCR-based results for 47, 48, 49, 50 and 52 were all consistent with Mr. Simpson?
In that series of five blood drops it is also correct that an RFLP match existed to Mr. Simpson, correct?
Turning to item no. 56, how many genetic markers typed using PCR were consistent with Nicole Brown?
And you would not include DQ-Alpha because one of the controls didn't operate properly?
Turning to item no. 78, how many PCR markers were consistent with both Ronald Goldman and Nicole Brown?
Well, there is a problem with that particular combination. Okay. I will--D1S80--there is six.
In other words, the five polymarkers and the DQ-Alpha result, those types showed a mixture, correct?
And in fact the results of those six markers showed that neither Nicole Brown nor Ronald Goldman could be excluded, correct?
Again when you get to mixtures on the polymarker, you really need to look at those systems that are informative in terms of if you have a combination that picks up both of them, then it includes everybody.
And in fact as to some of the polymarker results in mixtures, that is true, isn't it, where you see each of the combinations possible?
Turning to--and while we are on 78, as far as the RFLP technology, you have no quarrel with the fact that that particular sample produced a 5-probe RFLP match to both Nicole Brown and Ronald Goldman?
Turning to the nail clippings, and perhaps we can deal with them all at once, did they produce the same results on each of the three separate items?
How many different genetic markers produced results consistent with Nicole Brown on each of them?
And lastly, turning to the rear gate, stains 115, 116 and 117, as to item no. 117, does eight probes sound correct?
Dr. Gerdes, isn't it the case that with respect to the Bundy blood results the RFLP results confirm the PCR markers, whether it is one marker or all seven markers?
All right. Your Honor, at this time I would like to use exhibit 260, a similar results board.
Dr. Gerdes, referring you to what is People's exhibit 260, have you again either seen this board or a board with similar results?
Referring you to the first sample, item no. 23, from the interior of the Bronco, did that produce a result consistent with Mr. Simpson at one genetic marker typed following PCR?
Referring you to the second item, no. 24, how many genetic markers were typed that were consistent with Mr. Simpson?
Turning to the steering wheel, item no. 29, first of all, how many genetic markers were actually typed following PCR?
And with regard to those samples, is it your opinion also that from a review of those results that neither Mr. Simpson nor Nicole Brown can be excluded?
Incidentally, 30--I neglected to ask this. 30 produced a result from two markers consistent with Mr. Simpson?
31 produced a result at two markers consistent with both Mr. Simpson and Ronald Goldman?
Again this is the item where the weak 1.3 is in contention as far as I'm concerned, but that is what they say here, yes.
In other words, you have some criticism of the interpretation of that 1.3 allele, correct?
Turning to item no. 34, that result at one marker was consistent with Mr. Simpson?
What about item 293, the carpet on the driver's side, how many markers produced results that were consistent with Nicole Brown?
And then lastly, if we can deal with 303, 304 and 305 together, were there in fact two genetic markers that were typed following PCR with those evidence samples?
These are the evidence items, this last bunch, that were collected one month later.
Dr. Gerdes, items 303, 304 and 305 were typed at how many genetic markers following PCR?
Did they in fact produce results not excluding Mr. Simpson, Ronald Goldman or Nicole Brown?
And then lastly, your Honor, at this time I would like to utilize exhibit 262, a similar results board.
Doctor, again, People's exhibit 262, is that a board again similar to one that you have seen either in this form or a different form?
And with regard to the results starting with sock no. 13, that is the particular item that produced what was a total of a 16-probe match, but was fourteen different probes consistent with Nicole Brown, correct?
You have conceded or you have offered the opinion that that 14-probe match is in fact a correct one; is that right?
And in fact that is--in your opinion would that be an extremely significant match?
Again, there is controversy as to how to weigh these things, but in my opinion it is, yes, it would be.
So seven different genetic markers typed following PCR achieved the same results as far as consistency with Nicole Brown as the fourteen RFLP probe matches, correct?
In your opinion is that an example of an important cross-check between PCR and RFLP results?
If one of those PCR results produced a result that wasn't consistent with Nicole Brown, wouldn't that potentially raise a question about the reliability of PCR typing in forensics?
Turning to the remainder, and perhaps we can deal with the remaining samples, that is five more evidence items, correct?
And in fact the PCR results and the RFLP results were the same in being consistent with Mr. Simpson?
And then lastly, turning to 42B-1 and 42B-2, how many genetic markers were typed with those two samples?
Your Honor, for the record this board could be described as a board labeled "Concordance of Cellmark results with DOJ results."
Dr. Gerdes, with respect to, and let's start with the first item, 13A-1, is it correct, and we have discussed this to some extent a few moments ago, that the RFLP results obtained by each laboratory were consistent with one another, correct?
And that is with the fact that as to that sample there were a number of RFLP probes that matched Nicole Brown, correct?
There were also PCR results that you described a few moments ago that were also consistent with Nicole Brown from each laboratory, correct?
And in fact Cellmark's DQ-Alpha and polymarker results were consistent with the Department of Justice's DQ-Alpha and D1S80 results, correct?
Would this be an example where different laboratories achieve the same results from the same sample?
Turning to the steering wheel, that particular item was typed by Cellmark at six genetic markers and by DOJ at one of the same markers, DQ-Alpha, correct?
Turning to item 47 on the Bundy walkway, Cellmark's six genetic marker results were consistent with DOJ's two genetic marker results, one of which was typed by both laboratories, one marker?
Turning to item no. 48 from the Bundy walkway, is it correct that the six genetic markers typed by Cellmark were consistent with the two genetic markers typed by the Department of Justice, again one of which was the same DQ-Alpha marker?
In these instances, 47, 48, in fact two laboratories tested material from the same sample using the same genetic marker, didn't they?
Doesn't that constitute a cross-check of the accuracy of typing results by a laboratory?
Turning to item 50, again six genetic markers were typed at Cellmark and two genetic markers at DOJ, one of which was the same DQ-Alpha marker?
And then again two PCR-based markers were typed at the Department of Justice obtaining results the same as at Cellmark, correct?
And then lastly, turning to item no. 84, and that was a series of three different samples from fingernail clippings and scrapings, correct?
As far as the results from those two different laboratories, they are in fact consistent with one another in terms of the fact that Nicole Brown could not be excluded as the donor of that DNA, correct?
Isn't this inter-laboratory comparison, in fact, when one looks at the number of samples, a cross-check of the accuracy of results?
All right. Your Honor, I was going to change into another area that was going to take--actually be my final area, but it will take longer than five minutes.
Dr. Gerdes, this case doesn't involve testing of one or two evidence items, such as one or two bloodstains on a sidewalk, does it?
In fact, in this case there are more than forty different evidence samples that produced DNA typing results; isn't that correct?
Isn't it correct that with respect to the negative controls in this case, unstained substrate controls, that is one negative control, correct?
There is also a negative amplification control, as we discussed last Friday or Thursday?
Isn't it correct that all of those controls, the substrate controls, the reagent blank, the negative amplification controls in this case show no evidence of contamination?
There is one item from Cellmark that is a reagent blank that shows some evidence of contamination. With that one exception all the rest appear clean.
How many different runs did these approximately forty or more than forty evidence items include in this case? I'm referring to PCR results?
What is the most another sample--I'm referring to evidence material. What is the most times another sample would be run?
Well, in terms of the table that I formulated, it basically just refers to a specific date on which a series of strips were tested.
Okay. Were the same types of steps undertaken with regard to the evidence in this case?
So can we use the word "Run" to describe this different date that a sample might be typed in this case?
That would include amplification through actually determining which dots or which types are present?
With regard to these more than or approximately forty evidence items, how many different runs would those include in--you described that one sample might be run only once. How many times might another sample be run?
I would have to look at a specific item and count these things. I haven't done that.
If you count the runs in all the different laboratories, again, I--it is perhaps that many; perhaps not. I haven't counted them up, but there were a number of them.
All right. Mr. Clarke, Dr. Gerdes, why don't we take our break at this point. You can take a look and see what your records say. I don't want to rush you while you are on the stand here. Ladies and gentlemen, we are going to take our mid-morning break. Please remember all my admonitions to you. We will stand in recess for fifteen minutes. All right.
It says 'Lam flow.' Well, at that time I hadn't really noticed that this wasn't a laminar flow hood. I put down 'Laminar flow' and I didn't really realize until the second visit that this wasn't a laminar flow hood.
Most of our testing could be described as home-brewed as opposed to commercial kits.
I probably said that, but you have to look at the context around that... When you said it, did you mean it? Yes.
Yes... Yes... Yes... That's correct... No.
Dr. Gerdes, isn't it correct that item no. 52, the Bundy blood drop, matched Mr. Simpson at twelve different genetic markers?