Direct examination of Dr. John Gerdes (morning, part 2)

📄 Direct examination of Dr. John Gerdes (morning, part 2) — Thursday, August 3, 1995

Address:

C:\DEPT103\CRIMINAL\1995\AUG\3\DIRECT-EXAMINATION-OF-DR-JOHN-.DOC

TRIAL

▲ Day 128 of 167

◀ Sidebar: Rockingham glove foundation Sidebar: NRC report admissibility ▶

Witness: Dr. John Gerdes
Examiner: Barry Scheck
Called by: Defense • Date: Thursday, August 3, 1995 • Utterances: 100

Barry Scheck continued his direct examination of DNA lab director Dr. John Gerdes, focusing on whether cross-contamination could explain RFLP results for specific evidence items. Gerdes ruled out cross-contamination for the Rockingham glove, the sock (item 13-A), and the back gate (item 117), but said item 52 — with only 25 nanograms of DNA — could plausibly have been contaminated given the sample handling events of June 14th. Scheck then pivoted to shoring up Gerdes' credentials by walking through the non-forensic backgrounds of the NRC committee members who authored the authoritative report on DNA forensic science.

# 1 (The following proceedings were held in open court:)

# 2 MR. SCHECK:

As part of your analysis of the RFLP results have you considered and evaluated the sample handling procedures with respect to, for example, the Rockingham glove?

# 3 DR. GERDES:

Yes.

# 4 MR. SCHECK:

All right. Now, what is your view with respect to whether or not cross-contamination could have accounted for the RFLP results consistent with Ronald Goldman and Nicole Brown Simpson on the Rockingham glove.

# 5 MR. CLARKE:

Objection, no foundation.

# 6 THE COURT:

Overruled.

# 7 DR. GERDES:

In that particular case there is an adequate amount of DNA; it could not have been explained by cross-contamination.

KEY QUOTE

# 8 MR. SCHECK:

All right. Now, let me ask you with respect to the RFLP results obtained by the Department of Justice and Cellmark on the sock, particularly the cut-out section, 13-A, in terms of your review of the laboratory notes and how those samples were handled and the RFLP test results, do you believe cross-contamination could account for the RFLP results obtained on the sock?

# 9 DR. GERDES:

No. There is adequate amount of DNA. Cross-contamination could not have accounted for that particular RFLP.

# 10 MR. SCHECK:

All right. Now, do you know how the--how blood got on that sock?

# 11 DR. GERDES:

No, I don't.

# 12 MR. SCHECK:

All right. Do you believe that cross-contamination--have you reviewed the RFLP result on the item--LAPD item 117, a bloodstain collected from the back gate at Bundy on July 3rd?

# 13 DR. GERDES:

Yes.

# 14 MR. SCHECK:

All right. In terms of the way that sample was handled, what samples it was handled with in terms of reference tubes and other matters and amounts of DNA, is there anything that leads you to believe that cross-contamination could account for that RFLP result?

# 15 DR. GERDES:

On the back gate?

# 16 MR. SCHECK:

Yes.

# 17 DR. GERDES:

No. There is an adequate amount of DNA.

# 18 MR. SCHECK:

Have you--so you are distinguishing between those results and the RFLP result on item no. 52?

# 19 DR. GERDES:

Yes. Item 52 has significantly less DNA. It has only 25 nanograms of DNA and that certainly could have occurred, especially in the manner in which these samples were handled. That particular item could have occurred due to cross-contamination.

KEY QUOTE

# 20 MR. SCHECK:

And the events you described to us yesterday between --

# 21 DR. GERDES:

Yes.

# 22 MR. SCHECK:

--9:00 and 11:20?

# 23 DR. GERDES:

That's correct.

# 24 MR. SCHECK:

On June 14th?

# 25 DR. GERDES:

Correct.

# 26 MR. SCHECK:

Now, Dr. Gerdes, do you consider--have you heard paternity testing referred to as forensic science?

# 27 DR. GERDES:

Some people refer to it as that.

# 28 MR. SCHECK:

Because forensic, I suppose, has a definition that if it relates to court sometimes it is called forensic, quote-unquote?

# 29 DR. GERDES:

Yes. Some people define--forensics could be defined as a situation in which science and the practice of science interacts with law.

# 30 MR. SCHECK:

All right. Now, when we were discussing yesterday the contrast between clinical applications and forensics, did you take forensic to mean having to do with DNA--DNA--the application of DNA technology to crime scene samples?

# 31 DR. GERDES:

I believe that is what we were talking about at that time.

# 32 MR. SCHECK:

And so with that definition of forensic in mind, let me ask you these questions: First of all, in terms of your primary activity, are you a forensic scientist?

# 33 DR. GERDES:

I don't consider myself a forensic scientist, no.

KEY QUOTE

# 34 MR. SCHECK:

All right. Have you ever gone to a crime scene and done collections?

# 35 DR. GERDES:

No, I haven't.

# 36 MR. SCHECK:

Does your lab do forensic cases, that is, samples that are taken from crime scenes?

# 37 DR. GERDES:

No, we don't.

# 38 MR. SCHECK:

You do paternity testing?

# 39 DR. GERDES:

We do paternity testing.

# 40 MR. SCHECK:

All right. Do you attend forensic meetings with members of police labs, government labs, et cetera?

# 41 DR. GERDES:

No.

# 42 MR. SCHECK:

Based on your background as a microbiologist, a molecular biologist and a DNA lab director doing the kind of things you have described to the jury, do you feel you are able to assess the sample handling techniques, the methodology and the testing processes of forensic DNA laboratories that you've reviewed in this case, and I think you told us the 23 others that you reviewed previously?

# 43 DR. GERDES:

Yes, I believe I can.

# 44 MR. SCHECK:

All right. And you are familiar with their protocols and their practices?

# 45 DR. GERDES:

I am.

# 46 MR. SCHECK:

Now, this report, "DNA technology in forensic science"--

# 47 DR. GERDES:

Yes.

# 48 MR. SCHECK:

--this is by the national research council of the national academy of sciences?

# 49 DR. GERDES:

That's correct.

# 50 MR. SCHECK:

All right. And was this an analysis of the application of DNA technology to forensics in the sense that we have been just discussing it here, analysis of crime scene samples and the like?

# 51 DR. GERDES:

It was.

# 52 MR. SCHECK:

All right. And do you support the recommendations and analyses in this report?

# 53 DR. GERDES:

I do.

# 54 MR. CLARKE:

Objection, calls for hearsay.

# 55 THE COURT:

Overruled.

# 56 MR. SCHECK:

Now, are you familiar with the members of this committee and who they are?

# 57 DR. GERDES:

I don't know them personally, but I'm familiar with their credentials.

# 58 MR. SCHECK:

Have some of them included forensic scientists?

# 59 DR. GERDES:

I believe there are perhaps three individuals there who were forensic scientists, yes.

# 60 MR. SCHECK:

Including Dr. Henry Lee?

# 61 DR. GERDES:

Yes, Dr. Lee is one of those.

# 62 MR. SCHECK:

I'm sorry. Now, the chairman of this committee, Dr. Victor McKusick, is a forensic scientist?

# 63 DR. GERDES:

No, he is not.

# 64 MR. SCHECK:

But a molecular geneticist and biologist?

# 65 DR. GERDES:

That's correct.

# 66 MR. SCHECK:

Dr. Haig Kazazian, what field is he in?

# 67 DR. GERDES:

I believe it is in genetics.

# 68 MR. SCHECK:

And the medical applications of DNA technology?

# 69 DR. GERDES:

Yes.

# 70 MR. SCHECK:

Dr. Mary-Claire King, is she a forensic scientist?

# 71 DR. GERDES:

No.

# 72 MR. SCHECK:

But a molecular geneticist, population geneticist?

# 73 DR. GERDES:

Molecular biologist, yes.

# 74 THE COURT:

Gentleman, you are going to have to stop talking at the same time.

# 75 MR. SCHECK:

That is really my fault, your Honor. I'm really trampling on his answers.

KEY QUOTE

# 76 MR. SCHECK:

Dr. Eric Lander is a molecular geneticist and population geneticist?

# 77 DR. GERDES:

Yes.

# 78 MR. SCHECK:

All right. Is he is a forensic scientist?

# 79 DR. GERDES:

No.

# 80 MR. SCHECK:

Dr. Thomas G. Marr of the cold spring harbor laboratory, is he a molecular geneticist and biologist?

# 81 DR. GERDES:

Yes.

# 82 MR. SCHECK:

Is he a forensic scientist?

# 83 DR. GERDES:

No.

# 84 MR. SCHECK:

Now, one last series of questions, doctor. We discussed the issue of proficiency testing a little bit earlier. Are you familiar with the discussion of proficiency testing in the national research council report?

# 85 DR. GERDES:

I am.

# 86 MR. SCHECK:

Do you support those conclusions?

# 87 DR. GERDES:

Yes.

# 88 MR. SCHECK:

All right. I would like to direct your attention to a few--would the Court like to see them first before I read them?

# 89 THE COURT:

What page?

# 90 MR. CLARKE:

Could we just have a reference first--

# 91 MR. SCHECK:

Sure.

# 92 MR. CLARKE:

--before any questioning.

# 93 (Brief pause.)

# 94 MR. SCHECK:

Starting at page 89, the second and third paragraphs.

# 95 MR. CLARKE:

Could I just have a moment, your Honor?

# 96 (Brief pause.)

# 97 (Discussion held off the record between the Deputy District Attorneys.)

# 98 THE COURT:

Mr. Clarke.

# 99 MR. CLARKE:

Yes. May we be heard?

# 100 THE COURT:

Yes.

Temperature

procedural

Key Quotes (4)

Dr. John Gerdes

Item 52 has significantly less DNA. It has only 25 nanograms of DNA and that certainly could have occurred, especially in the manner in which these samples were handled. That particular item could have occurred due to cross-contamination.

Gerdes explicitly singles out item 52 as the one RFLP result that contamination could explain — a critical distinction that undermines a specific piece of prosecution DNA evidence.

Dr. John Gerdes

In that particular case there is an adequate amount of DNA; it could not have been explained by cross-contamination.

Gerdes draws a careful line: his contamination argument is targeted, not a blanket attack on all DNA results, which lends his testimony credibility and precision.

Dr. John Gerdes

I don't consider myself a forensic scientist, no.

A candid admission Scheck defuses by immediately pivoting to show that the NRC report's own committee was also dominated by non-forensic scientists.

Barry Scheck

That is really my fault, your Honor. I'm really trampling on his answers.

Rare moment of self-deprecation from Scheck; also signals the well-rehearsed rhythm of this examination.

Evidence (5)

Informal

Rockingham glove — RFLP results consistent with Ronald Goldman and Nicole Brown Simpson

discussed; Gerdes ruled out cross-contamination as explanation

Item 13-A

Cut-out section of the sock — RFLP results tested by DOJ and Cellmark

discussed; Gerdes ruled out cross-contamination as explanation

LAPD Item 117

Bloodstain collected from back gate at Bundy on July 3rd

discussed; Gerdes ruled out cross-contamination as explanation

Item 52

Unspecified bloodstain with only 25 nanograms of DNA

discussed; Gerdes said cross-contamination could account for the RFLP result given June 14th handling events

Informal

NRC report: 'DNA Technology in Forensic Science' by the National Research Council / National Academy of Sciences

introduced and endorsed by Gerdes; Clarke requested page reference before questioning

Notable Exchanges (3)

Barry Scheck•Dr. John Gerdes

Scheck walked Gerdes through item 52 versus items 117, 13-A, and the Rockingham glove — eliciting that contamination applies only to item 52, making the critique surgical rather than sweeping.

strategic

Barry Scheck•Dr. John Gerdes

Scheck ran through the credentials of each NRC committee member (McKusick, Kazazian, King, Lander, Marr) to establish that non-forensic scientists — like Gerdes himself — are considered authoritative in this field.

strategic

George Clarke•Barry Scheck•Judge Ito

Clarke asked for a page reference before Scheck read from the NRC report; Ito paused for a discussion off the record among the prosecution, ending the transcript.

procedural

Light Moments (1)

Judge Ito / Barry Scheck

Judge Ito had to intervene because Scheck and Gerdes were talking over each other; Scheck immediately took the blame with disarming candor.

Credibility Attacks (1)

⚔ Dr. John Gerdes

preemptive rehabilitation

Anticipating prosecution attacks on Gerdes' lack of forensic science credentials, Scheck elicited that Gerdes does not call himself a forensic scientist, then immediately showed that the NRC committee — the gold standard in the field — was also dominated by molecular geneticists and biologists rather than forensic scientists.

Witness Demeanor

(Brief pause.) — during page reference lookup for NRC report

(Discussion held off the record between the Deputy District Attorneys.)

Objections

2 objections (0 sustained, 2 overruled)

Proceeding 7939 • 100 utterances • Defense witness

Criminal Trial

Department 103