All right. Thank you, ladies and gentlemen. Please be seated. Dr. Gerdes, would you resume the witness stand, please.
John Gerdes, the witness on the stand at the time of the lunch recess, resumed the stand and testified further as follows: THE COURT: All right. Good afternoon again, doctor.
You are reminded, sir, you are still under oath. Mr. Scheck, you may continue with your redirect.
Thank you, your Honor. Good afternoon, ladies and gentlemen of the jury.
THE JURY: Good afternoon.
REDIRECT EXAMINATION (RESUMED) BY MR. SCHECK
Dr. Gerdes, let me discuss with you briefly the results on the glove. And I'd like to show you first the results of DNA analysis, Rockingham glove, which is Prosecution's 272. Now, Dr. Gerdes, Mr. Clarke asked you about the results from RFLP tests that were consistent with Nicole Brown Simpson and Ronald Goldman on various areas of the glove, specifically G1, G2, G3, G4, G9, that were confirmed by RFLP--well, G4--I'm sorry--that were confirmed by RFLP tests, correct?
All right. G11, G10 and G13 are the D1S80 results in the wrist area of the glove which produced results with Mr. Simpson; is that correct?
Now, putting on the--this is Defense 1186, Mr. Yamauchi's diagram of the glove found at Rockingham. Dr. Gerdes, is this the--this diagram reflect what your understanding is of the--what Mr. Yamauchi did on the morning of June 14th between 9:00 and 10:00 o'clock when he handled the glove from Rockingham after having handled Mr. Simpson's reference sample where he had that incident where the--took off the top and the blood went through the chemex and onto his glove?
Well, as far as the D1S80 results from the wrist area of the glove, what is your opinion as to the acceptable risks of cross-contamination with respect to those results?
They were handled the same time or shortly after Mr. Simpson's reference sample was handled. The testimony states that the sample had leaked, and under those circumstances, it represents substantial risk that contamination could have happened.
Are the D1S80 results in terms of the amount of DNA found in the wrist area of that glove consistent with cross-contamination from the sample handling error?
On the basis of the amounts of DNA in those D1S80 tests and your review of the procedures that Mr. Yamauchi used, do you believe--what do you believe about the level of risk of cross-contamination with respect to those results?
This is Defense 1308, testing results, Nicole Brown Simpson and Ronald Goldman reference samples. Now, Mr. Clarke asked you a series of questions about controls and evidence of cross-contamination from the way that samples were handled in the evidence processing room on June 14th and June 15th. Do you recall those?
All right. With respect to cross-contamination occurring in the handling of samples by Mr. Yamauchi on June 15th, specifically item 12, the last blood sample collected from the foyer in Mr. Simpson's home and Nicole Brown Simpson reference sample and Ron Goldman reference sample, do you believe that the results shown on this board are consistent with cross-contamination that was then retyped in two different laboratories, Cellmark and DOJ?
Are the results from this board part of the basis for your opinion that there were unacceptable risks of contamination in the way Mr. Yamauchi handled those samples on June 14th and June 15th?
Yes. These results were consistent with evidence that cross-contamination actually happened.
Now, Dr. Gerdes, you were asked--let me show you what is--this is Defense 1297, a chart depicting runs and strips May through July of 1994, run contamination, strip contamination and/or artifacts. Now, Dr. Gerdes, you were asked quite a number of--you were asked quite a number of questions on cross examination about the distinction you made when analyzing strips where you put--you indicated there were strip contamination and/or artifacts. You recall those?
And these are a series of strips that the Prosecution showed to demonstrate the weak 1.1 and I believe in reference to discussing the DX allele.
And it was your--was it your testimony that in looking at that 1, you could not tell if that was--that is, the 1.1's were contaminants or artifacts?
That's correct. Under this circumstance, you can't really tell if that's an artifact or contaminant.
Yes. In terms of the strips, that's the reason why I did not really try to differentiate between the two because in many--situations such as this, you can't tell.
Now, what relation--what relationship does a result such as depicted on 566, where you can't tell if it's a contaminant or artifact, have in terms of making erroneous typings?
What is--why is it--what are the problems you see in the results such as depicted on 566 in terms of making an interpretation of the strip?
Well, on--if you look at the strip that has the 1.1 allele, the weak 1.1 allele, if this were a crime scene specimen, the interpretation of that would be that particular item where type is a 1.2, 1.2 because you can see the 1.2 signal here is dark and the 1 is dark; and for that reason, this would be probably typed as a 1.2, 1.2. but because of the weak 1.1, most likely, they would express the fact that that was present there and visible. And so it would be a 1.2, 1.2 consistent with a contributor of--with a 1.1. so it would be consistent with an individual with a 1.1, 1.1 or an individual with a 1.1, 1.2. so that obviously makes this a--that artifact has a potential of falsely accusing an individual who's a 1.1, 1.2 when in fact typing results is from a 1.2, 1.2.
Well, doctor, let me see if I can try to put this in as plain as English as I can. Is the existence of a faint dot like that in a mixture, can that cause an error?
Yes. And it doesn't matter if it's an artifact or a real contaminant. Either way, it can cause an error.
KEY QUOTEAre dots of that intensity similar to the 1.3 dot we saw before on item 31 of the Bronco console?
Dr. Gerdes, you recall Mr. Clarke asking you questions about whether or not two analysts ever did samples on the same day in your calculation of runs? Remember that?
Now, do these runs, as you recorded them by month, represent contamination, definite contamination on the day all the strips were run?
Yes. At this point, they're definite contamination because I take all of the strips on a given date and I can look in the context of what's in that--in all of those strips so that you can confirm with one strip whether you're seeing the same thing in more than one strip.
So this chart represents definite contamination, no ambiguity about artifacts as far as you're concerned?
By the standards that you were familiar with to accredit DNA laboratories, given this level of contamination in runs, in your opinion, would the Los Angeles Police Department be allowed to operate?
Are you familiar with the standards used to regulate DNA laboratories in clinical applications?
By those standards, would a lab be allowed to operate with this level of contamination?
Now, Dr. Gerdes, you were--excuse me. You were asked a whole series of questions by Mr. Clarke in regard to the use of PCR in other clinical applications. Do you recall those?
If PCR base test is reliable for some clinical applications, does that mean it is reliable for all others?
Does the reliability of a PCR base technique depend on the standards and the quality of the lab that's using the technique?
Does the fact that the DQ-Alpha kit is sold commercially with the user guide mean that this technique is reliable for all forensic uses by all forensic laboratories?
Doctor, have you read--Mr. Clarke asked you a whole series of questions about kits. Do you recall those?
All right. Do you--are you familiar with the discussion in the NRC report with respect to the kits that were used in this case?
Your Honor, we would like to--I've shown this to Mr. Clarke. I'd like to put a slide on the screen.
Do you agree with the following statement in the NRC report? "One commercial kit for forensic PCR analysis has been marketed." Now, let me just stop there. What kit is that?
"Other kits will probably be ready for commercial market soon." What kits would those be?
"The committee sees a potential for introduction of unreliable kits and the misuse of kits. The existence of a kit suggests ease of use and low chance of technical error. The committee believes that nonexpert laboratories will run a significant chance of error in using kits." Do you agree with that?
What is your opinion about this--this--what the NRC said and the LAPD laboratory in this case?
I believe that the situation we've seen here is precisely what the NRC is talking about here.
KEY QUOTEBecause the LAPD has made substantial errors and have failed to see the subtleties that are critical to interpretation of this kind of testing due to the fact that they were inexperienced.
KEY QUOTEDr. Gerdes, very quickly, you were asked a lot of questions about proficiency tests. Does it make a difference in proficiency tests that the tests involve samples that are just like the ones that you deal with in casework?
All right. Do you recall Mr. Clarke asked you about the laminar flow hood in your--and the records you made in your notes, correct?
All right. Can you please explain when you realized that the LAPD did not have a laminar flow hood?
Is the fact that it's not a laminar flow hood, does that create dangers of contamination in the laboratory?
Is a laminar flow hood a fundamental in terms of taking precautions against contamination in a DNA laboratory?
Is it disturbing to you that the Los Angeles Police Department DNA laboratory did not--was not aware that its hood was not a laminar flow hood?
What is the significance of this hood not being a laminar flow hood in terms of the level of competence and knowledge of the personnel at the LAPD DNA laboratory?
All right. In terms of the ability--based on your experience as a DNA laboratory director, what is your opinion about laboratory personnel being unaware of the nature of the hood they're using when processing samples?
In terms of the reliability of the procedures used at the Los Angeles Police Department in handling DNA samples, what in your judgment is the significance of their failure to know that their hood was not a laminar flow hood?
The issue here is, what's the benefit to having a laminar flow hood versus what's there. That's the real issue.
KEY QUOTEThe laminar flow hood is designed to--for the applications where you're concerned about either contaminating an item or being contaminated by that item. That's what they're designed for. That's what their purpose is. A chemical fume hood was designed for an entirely different purpose which is not appropriate for handling those kind of samples.
If you're working in a DNA laboratory, in your opinion, is it important to know the difference between a chemical hood and a laminar flow hood?
Now, you were asked many questions on cross-examination concerning your conclusions about incorrect typing results by the Los Angeles Police Department personnel on mock validation studies and proficiency tests. Do you recall those?
Now, I'm going to show you some slides, but first, I'd like to just refresh everybody's recollection with showing the raw data. The first mock validation study was one--if you can pull back--done by Mr. Yamauchi on September 9th. Do you recall that?
Then the second one was the same set of samples typed on September 21st by Erin Riley. You recall that?
On the far left, it represents the correct type for this particular mock validation specimen. So the little symbol on top there stands for the male fraction. The male fraction should be a 1.2, 1.3. the next one below the epithelial cell or the female fraction should be 1.2, 4.
No. You can see it does not match the anticipated male pattern that should have been there. The 1.2, 1.3 is not equal to 1.2, 4.
All right. Tell us what this represents in terms of the consequences of that mistyping.
What that means is the--given the LAPD type of 1.2, 4, if the suspect were a 4.4, a 1.2, 4 or a 1.2, 1.2, all of those individuals would be included as having matched that male fraction.
Well, since the true and correct type was missed, the 1.2, 1.3 was missed, the true perpetrator would not have been recognized and so he would have been excluded falsely. So, again, that's an error.
And is this the--are these among the reasons that you believe that these were erroneous typings?
Is this one reason you disagree with the statement in the validation study that no incorrect results were observed?
You also discussed two other errors by--in proficiency tests. First one just to show the raw data--
These were proficiency samples that were part of--well, part of a proficiency test.
the LAPD has made substantial errors and have failed to see the subtleties that are critical to interpretation of this kind of testing due to the fact that they were inexperienced.
I believe that the situation we've seen here is precisely what the NRC is talking about here.
it doesn't matter if it's an artifact or a real contaminant. Either way, it can cause an error.
these suspects would have been wrongly accused.
The issue here is, what's the benefit to having a laminar flow hood versus what's there. That's the real issue.