Cross-examination of Dr. Robin Cotton (part 1)

📄 Cross-examination of Dr. Robin Cotton (part 1) — Thursday, May 11, 1995

Address:

C:\DEPT103\CRIMINAL\1995\MAY\11\CROSS-EXAMINATION-OF-DR-ROBIN-.DOC

TRIAL

▲ Day 72 of 167

◀ Jury preparation and exhibits Sidebar: hypothetical questions and cross-contamination ▶

Witness: Dr. Robin Cotton
Examiner: Peter Neufeld
Called by: Prosecution • Date: Thursday, May 11, 1995 • Utterances: 66

Peter Neufeld opens his cross-examination of DNA expert Dr. Robin Cotton by first establishing that she never heard the defense argue degradation changes one person's DNA into another — reframing what the prosecution had implied. He then methodically constructs a lengthy contamination hypothetical: if the Bundy blood drops were not Simpson's and had fully degraded, and if those swatches were then brought into contact with Simpson's undegraded Rockingham samples (particularly item 12) at the LAPD lab, could accidental cross-contamination explain the matching DNA results? The proceeding ends abruptly mid-objection, with Clarke calling for a sidebar just as Neufeld reaches the crux of the theory.

# 1 (The following proceedings were held in open court, in the presence of the jury:)

# 2 THE COURT:

All right. Thank you, ladies and gentlemen. Please be seated. Dr. Cotton, would you resume the witness stand, please. All right. Mr. Clarke, as to the items presented thus far, you've completed your direct examination subject to the reopening, correct?

# 3 MR. CLARKE:

Yes, your Honor.

# 4 THE COURT:

Mr. Neufeld, you may commence your cross-examination.

# 5 MR. NEUFELD:

Thank you, your Honor. Good afternoon, ladies and gentlemen.

THE JURY: Good afternoon.

CROSS-EXAMINATION BY MR. NEUFELD

# 6 MR. NEUFELD:

Good afternoon, Dr. Cotton.

# 7 DR. COTTON:

Good afternoon.

# 8 MR. NEUFELD:

Now, Dr. Cotton, on direct examination, you were asked repeatedly during the direct examination whether or not degradation, okay, the process of degradation could change one person's DNA into another, and I believe that each time you answered that question, you said no; is that right?

# 9 DR. COTTON:

That's right.

# 10 MR. NEUFELD:

And by the way, have you been following this trial at all?

# 11 DR. COTTON:

Uh, I've watched, uh, part of the opening arguments and then bits and pieces of testimony and maybe 30 minutes here and there as the trial's gone along.

# 12 MR. NEUFELD:

Okay. Have you at all at any time during these proceedings that you followed, Dr. Cotton, ever heard either Mr. Blasier, Mr. Scheck or myself suggest to any witnesses at all that through the process of degradation, a person's blood could change from one person to another?

KEY QUOTE

# 13 MR. CLARKE:

Objection. Irrelevant.

# 14 THE COURT:

Sustained.

# 15 MR. NEUFELD:

Well, let me ask you a hypothetical, Dr. Cotton. Like you to assume for a moment that the blood drops that were recovered from Bundy do not come from Mr. Simpson, but instead come from some other person, and I would also like you to assume for the purpose of this hypothetical that the blood drops recovered at Rockingham are indeed Mr. Simpson's blood. All right?

# 16 DR. COTTON:

Okay.

# 17 MR. NEUFELD:

Thank you. Now, I would also like you to assume for the purpose of this hypothetical that due to the manner in which the Bundy blood drops were collected, packaged and processed, that they became degraded. Okay?

# 18 DR. COTTON:

Okay.

# 19 MR. NEUFELD:

And, in fact, you've described I think in detail during direct examination how bloodstains or blood drops can become degraded; isn't that right?

# 20 DR. COTTON:

Yes.

# 21 MR. NEUFELD:

For instance, in this case, you mentioned that the--

# 22 THE COURT:

Excuse me, counsel. We're going to have to move this easel because it's blocking two of the jurors' view of Dr. Cotton.

# 23 MR. NEUFELD:

Okay. Sorry.

# 24 (Brief pause.)

# 25 THE COURT:

All right. Thank you, counsel. Proceed.

# 26 MR. NEUFELD:

Sorry.

# 27 MR. NEUFELD:

For instance, you mentioned during direct examination that item 56--and I'm asking that item 56, which is exhibit no. 256, go up on the elmo.

# 28 MR. NEUFELD:

One moment, your Honor.

# 29 (Brief pause.)

# 30 MR. NEUFELD:

And I believe if you would, if you could stand and just use the pointer to point out to the jury where lane 56 is again.

# 31 DR. COTTON:

Down here you mean (Indicating).

# 32 MR. NEUFELD:

Well--

# 33 DR. COTTON:

Yes.

# 34 MR. NEUFELD:

Come over. Come over a little. Now back up one. Blank lanes. There.

# 35 (Brief pause.)

# 36 MR. NEUFELD:

Okay. Is that lane--is that the lane reflecting a DNA test on item 56?

# 37 DR. COTTON:

Yes, it is.

# 38 MR. NEUFELD:

Okay. And as you can see, and I believe as you testified, that lane is clear, right?

# 39 DR. COTTON:

That's right.

# 40 MR. NEUFELD:

And that's an indication that the DNA from that sample degraded considerably; isn't that correct?

# 41 DR. COTTON:

Yes.

# 42 MR. NEUFELD:

And, in fact--

# 43 (Discussion held off the record between Defense counsel.)

# 44 MR. NEUFELD:

And when you first looked at item 56 in the laboratory, before you even looked at it on the level of DNA, you just saw these swatches, you couldn't tell us from just looking at it that the DNA was degraded; isn't that right?

# 45 DR. COTTON:

Of course.

# 46 MR. NEUFELD:

And to the naked eye, in fact, it didn't look any different than item--than item 52 for instance, did it?

# 47 DR. COTTON:

That's right.

# 48 MR. NEUFELD:

Now--

# 49 (Discussion held off the record between Defense counsel.)

# 50 MR. NEUFELD:

Now, I would like you to assume, ma'am--Dr.--excuse me--

# 51 DR. COTTON:

Either way is fine.

# 52 MR. NEUFELD:

Okay. What I would like you to assume, Dr. Cotton, is that those drops on Bundy which did not--which were not left by Mr. Simpson, but were--became degraded in the packaging or handling process such that all the DNA that was in that sample and on those swatches was completely lost to degradation, okay?

# 53 DR. COTTON:

Okay.

# 54 MR. NEUFELD:

Now, what I would like you to assume is that when those swatches from the Bundy drops get back to the Los Angeles Police Department laboratory, they are brought into contact with the swatches from Rockingham, which I've already asked you to assume came from Mr. Simpson, okay?

# 55 DR. COTTON:

Okay.

# 56 MR. NEUFELD:

And that the Rockingham drops or at least some of them, such as item no. 12, were not very degraded, okay?

# 57 DR. COTTON:

That's right.

# 58 MR. NEUFELD:

And I believe you even said on direct examination that item 12 seemed to be in good shape relatively speaking?

# 59 DR. COTTON:

It does.

# 60 MR. NEUFELD:

And--and so there was a lot more DNA in item 12 than there was, for instance, item 52; is that right?

# 61 DR. COTTON:

That's right.

# 62 MR. NEUFELD:

In fact, a lot more DNA on item 12 which comes from Mr. Simpson's foyer than there was on any of the drops from Rockingham; isn't that right?

# 63 DR. COTTON:

That's right.

# 64 MR. NEUFELD:

And what I would like you to assume for the purpose of this hypothetical, Dr. Cotton, is that these blood drops, stains from Bundy, when they're brought back to Los Angeles Police Department laboratory, came into contact with Rockingham drops which had more DNA in it and that those swatches from Rockingham cross-contaminated by accident the swatches from Bundy, okay?

KEY QUOTE

# 65 MR. CLARKE:

I'm sorry, your Honor. Objection.

# 66 THE COURT:

Let me see counsel at sidebar, please, with the reporter.

Temperature

tense

Key Quotes (4)

Peter Neufeld

Have you at all at any time during these proceedings that you followed, Dr. Cotton, ever heard either Mr. Blasier, Mr. Scheck or myself suggest to any witnesses at all that through the process of degradation, a person's blood could change from one person to another?

Neufeld corrects the record on the defense's actual theory — they never claimed degradation transforms DNA identity — reframing the prosecution's attack on a straw man.

Peter Neufeld

I would like you to assume for the purpose of this hypothetical that those drops on Bundy which did not--which were not left by Mr. Simpson, but were--became degraded in the packaging or handling process such that all the DNA that was in that sample and on those swatches was completely lost to degradation.

The explicit statement of the contamination theory: Bundy drops weren't Simpson's, they degraded to nothing, then Simpson's DNA from Rockingham cross-contaminated them at the lab.

Dr. Robin Cotton

Either way is fine.

Small moment of warmth when Neufeld fumbles between 'ma'am' and 'Dr.' — Cotton is relaxed and unguarded at this point, before the hypothetical gets serious.

Dr. Robin Cotton

That's right.

Cotton confirms item 12 (Rockingham foyer) had significantly more DNA than any of the Bundy drops — a key factual concession supporting the contamination vector Neufeld is building.

Evidence (3)

People's 256 (item 56)

Blood swatch from Bundy crime scene; showed a clear/blank lane on gel electrophoresis, indicating severe DNA degradation

displayed on Elmo, discussed to establish that degraded samples look identical to intact ones to the naked eye

Informal

Item 52 — Bundy blood drop, used as comparison to item 56 regarding visual appearance of degraded vs. intact swatches

referenced informally

Informal

Item 12 — blood drop from Simpson's Rockingham foyer, described as 'in good shape' with significantly more DNA than any Bundy sample

discussed as the contamination source in Neufeld's hypothetical

Notable Exchanges (2)

Peter Neufeld•Dr. Robin Cotton

Neufeld walks Cotton through a multi-step contamination hypothetical — Bundy drops not Simpson's, fully degraded, brought into contact with Simpson's undegraded Rockingham samples at the LAPD lab — getting Cotton to confirm each factual predicate before the objection cuts it off.

strategic

Peter Neufeld•George Clarke•Lance A. Ito

Clarke objects as Neufeld reaches the payoff question of the contamination hypothetical; Ito calls sidebar. The proceeding ends before Cotton can answer the central question.

procedural

Light Moments (2)

Dr. Robin Cotton

Neufeld fumbles mid-question between 'ma'am' and 'Dr.' when addressing Cotton; she replies 'Either way is fine.'

Lance A. Ito

Ito interrupts mid-question to have the easel moved because it's blocking two jurors' view of the witness.

Credibility Attacks (1)

⚔ LAPD evidence handling (not Cotton directly)

hypothetical framing

Neufeld uses Cotton's own expertise to build the contamination theory without directly accusing her — getting her to confirm the factual predicates (item 56 fully degraded, item 12 rich with DNA, swatches handled together at LAPD lab) that would support the defense's narrative that Simpson's DNA was accidentally transferred onto Bundy evidence.

Witness Demeanor

Calm and cooperative throughout; answers straightforwardly without resistance

Steps up to use the pointer on the Elmo display without prompting

Relaxed enough to joke about 'either way is fine' when Neufeld stumbles over her title

Objections

2 objections (1 sustained, 0 overruled)

Proceeding 6033 • 66 utterances • Prosecution witness

Criminal Trial

Department 103