Recross-examination of Collin Yamauchi (afternoon)

📄 Recross-examination of Collin Yamauchi (afternoon) — Wednesday, May 31, 1995

Address:

C:\DEPT103\CRIMINAL\1995\MAY\31\RECROSS-EXAMINATION-OF-COLLIN-.DOC

TRIAL

▲ Day 85 of 167

◀ Court admonition Redirect examination of Collin Yamauchi (afternoon) ▶

Witness: Collin Yamauchi
Examiner: Barry Scheck
Called by: Prosecution • Date: Wednesday, May 31, 1995 • Utterances: 112

Barry Scheck concludes his recross-examination of LAPD criminalist Collin Yamauchi, pressing him on three areas: whether he performed microscopic examination for sperm cells during a 1993 mock vaginal swab exercise, whether he understood at the time of recording that a DQ-Alpha result labeled 'sperm contribution' was actually epithelial cell spillover, and whether he observed any blood discoloration or reddish particles on the sock (Item 13) during the original June 29th examination. Yamauchi repeatedly admitted uncertainty about his own contemporaneous observations and reasoning.

# 1 THE COURT:

Thank you, ladies and gentlemen. Please be seated. The record should reflect we have been rejoined by all the members of our jury. Mr. Collin Yamauchi is again on the witness stand undergoing recross-examination by Mr. Scheck. Mr. Scheck, you may continue.

# 2 MR. SCHECK:

Mr. Yamauchi, just three or four more different questions about this mock vaginal swab exercise. Is there a procedure that is commonly employed by forensic analysts whereby one can look under a microscope at a vaginal swab and literally see sperm cells?

# 3 MR. HARMON:

Objection, beyond the scope. It is irrelevant.

# 4 THE COURT:

Overruled.

# 5 MR. YAMAUCHI:

Yes, you can take a microscopic examination of that.

# 6 MR. SCHECK:

And after such a microscopic examination one could determine whether or not there were any sperm cells in the sample?

# 7 MR. YAMAUCHI:

Yes, that's correct.

# 8 MR. SCHECK:

Did you do that here?

# 9 MR. YAMAUCHI:

I may or may not have at that point. You understand that was back in the beginning before we started case work. As far as when we do case work, that is a part of our protocol and procedure, to document that to that detail of whether or not we can see the spermatozoa.

# 10 MR. SCHECK:

Do you have any notes indicating that you performed such an examination in this exercise?

# 11 MR. YAMAUCHI:

No, I don't.

# 12 MR. SCHECK:

Was the purpose of this exercise to simulate the techniques that you would use in a real case?

# 13 MR. YAMAUCHI:

Well, yes, it was, and to a certain extent we are evolving and trying to decide what were the important needs and what we didn't do, and obviously we came to the conclusion that we needed that microscopic examination because that is what we do in our case work today.

# 14 MR. SCHECK:

Let me see. Did you just say to me a second ago that you don't know whether you did or did not look at this sample under a microscope?

# 15 MR. YAMAUCHI:

Yes, I did.

# 16 MR. SCHECK:

So you might have done that?

# 17 MR. YAMAUCHI:

Yes, I might have.

# 18 MR. SCHECK:

Are you telling us now that as a result of the mock vaginal swab exercise you realized that you had to institute a procedure of looking at samples under a microscope to see whether there were sperm cells? Is that what you are saying now?

# 19 MR. HARMON:

Objection, argumentative, irrelevant, beyond the scope.

# 20 THE COURT:

Overruled.

# 21 MR. YAMAUCHI:

It is not critical to the result, but it does give us information that we can use to troubleshoot later on.

# 22 MR. SCHECK:

Well, the point of looking at it under a microscope is to see whether there are any sperm cells?

# 23 MR. YAMAUCHI:

Yes.

# 24 MR. SCHECK:

Now--

# 25 THE COURT:

All right, counsel.

# 26 MR. SCHECK:

Your Honor, he was--you didn't let me--

# 27 THE COURT:

I understand that.

# 28 MR. SCHECK:

Just one more--

# 29 THE COURT:

One more.

# 30 MR. SCHECK:

--point about this.

# 31 MR. SCHECK:

When you reported the type result 1.2, 4 for the sperm contribution in this exercise--

# 32 MR. YAMAUCHI:

That's the fraction. The sperm cell fraction.

# 33 MR. SCHECK:

Right. On September 3rd--okay? Are you with me?

# 34 MR. YAMAUCHI:

Yes.

# 35 MR. SCHECK:

--when you did that, did you believe the 1.2, 4 was the sperm contribution?

# 36 MR. YAMAUCHI:

No. It had all the signs of being spill over from the epithelial cell fraction.

# 37 MR. SCHECK:

Did you note--so it is your testimony, sir, that when you saw that 1.2, 4, for the sperm fraction on the hybridization strip for 14-6, that you knew in your mind at that time when you wrote down 1.2, 4, that that wasn't really the sperm contribution, that was the epithelial cell contribution?

# 38 MR. HARMON:

Objection, it is argumentative.

# 39 THE COURT:

Sustained. Rephrase the question.

# 40 MR. SCHECK:

All right.

# 41 MR. SCHECK:

Is it your testimony that when you wrote down 1.2, 4 on September 3rd for the epithel--for the sperm cell contribution, you knew at that time that that 1.2, 4 was actually the epithelial cell, not the sperm cell?

# 42 MR. YAMAUCHI:

You mean spilling over?

# 43 MR. SCHECK:

Yeah.

# 44 (No audible response.)

# 45 MR. SCHECK:

When you wrote down 1.2, 4 for sperm cell did you know at that time when you wrote it that that was not the sperm contribution, that was the epithelial cell contribution?

# 46 MR. YAMAUCHI:

Well, I don't know if at that time I did or not. Basically what I do is I go through them and I read off and write down my results exactly what I see on the strips, so it might have been at a later time when I went back to analyze it further that I realized that.

KEY QUOTE

# 47 MR. SCHECK:

When did you go back and analyze it further and realize that?

# 48 MR. YAMAUCHI:

I don't know.

# 49 MR. SCHECK:

Did you ever talk about that with any supervisor, the result of September 3rd, 1993?

# 50 MR. HARMON:

Objection.

# 51 THE COURT:

I don't think so. I don't think so.

# 52 MR. SCHECK:

I'm sorry?

# 53 THE COURT:

No.

# 54 MR. SCHECK:

All right.

# 55 MR. SCHECK:

Did you ever--

# 56 THE COURT:

Counsel, I have let a lot of cross-examination into this area--

# 57 MR. SCHECK:

Okay.

# 58 THE COURT:

--but it is not directly relevant to the processing in this case. I think we have exhausted this.

# 59 MR. SCHECK:

Can I ask one last question?

# 60 THE COURT:

One question.

# 61 MR. SCHECK:

Under the standards of your laboratory, as far as you are concerned, you got the right answer on this mock vaginal swab study with respect to the sperm contribution?

# 62 MR. HARMON:

Objection, asked and answered.

# 63 THE COURT:

Sustained.

# 64 MR. SCHECK:

Mr. Yamauchi, you mentioned on redirect examination that DNA tests have been done on mummies?

# 65 MR. YAMAUCHI:

Well, I have seen a book published on that subject.

# 66 MR. SCHECK:

Have you read it?

# 67 MR. YAMAUCHI:

I have glanced through it.

# 68 MR. SCHECK:

Have you read articles about it?

# 69 MR. YAMAUCHI:

Umm, may have.

# 70 MR. SCHECK:

To your knowledge has a DQ-Alpha PCR-based test ever been successfully completed on remains of a mummy?

# 71 MR. YAMAUCHI:

I can't say that specifically I read that. I'm not sure.

# 72 MR. SCHECK:

Do you--do you think from--do you recall from what you read whether there would be sufficient DNA in the remains of a mummy to perform a DQ-Alpha PCR-based DNA test?

# 73 MR. YAMAUCHI:

Well, I think it is completely possible, but I wouldn't know unless I actually read that.

# 74 MR. SCHECK:

Uh-huh. Now, you indicated on redirect examination that you had encountered situations before where dark surfaces hide blood?

# 75 MR. YAMAUCHI:

Well, the background makes it hard to--well, doesn't make the blood very obvious.

# 76 MR. SCHECK:

And that was something that you knew on June 29th when you were examining the sock with Michele Kestler and Greg Matheson?

# 77 MR. YAMAUCHI:

Well, certainly we could see that it was a dark-colored sock.

# 78 MR. SCHECK:

Well, you knew that dark surfaces, in your words, can sometimes hide blood?

# 79 (No audible response.)

# 80 MR. SCHECK:

You knew that?

# 81 MR. YAMAUCHI:

Yeah, it can made make it hard to see.

# 82 MR. SCHECK:

Now, you testified on redirect examination that yesterday you went back into the laboratory with Greg Matheson and you looked under a stereomicroscope to see if yesterday you could see discolorations in the sock under the stereomicroscope?

# 83 MR. YAMAUCHI:

Actually that was this morning.

# 84 MR. SCHECK:

All right. You did that this morning?

# 85 MR. YAMAUCHI:

Yes.

# 86 MR. SCHECK:

You did that with Mr. Sims as well?

# 87 MR. YAMAUCHI:

Yes.

# 88 MR. SCHECK:

Okay. Now, you can't tell this jury anything about whether what you saw under the stereomicroscope last night was on the sock on June 29th?

# 89 MR. YAMAUCHI:

You mean this morning?

# 90 MR. SCHECK:

Yeah, what you saw this morning was on the sock on June 29th?

# 91 MR. HARMON:

Objection. It is argumentative, your Honor.

# 92 THE COURT:

Overruled.

# 93 MR. YAMAUCHI:

No, I wouldn't know that because we didn't have a stereomicroscope at the time.

KEY QUOTE

# 94 MR. SCHECK:

Well, when you examined the sock on June 29th none of those cut-outs that we observed yesterday were there?

# 95 MR. YAMAUCHI:

No, the sock was intact.

# 96 MR. SCHECK:

And the place that I pointed out to you on sock around the ankle area, would you agree was about three-quarters of an inch long and about a half an inch wide, cut-out area?

# 97 MR. YAMAUCHI:

I recall something more like a centimeter by four centimeters. I believe that is what I said, too. I'm not sure, though.

# 98 MR. SCHECK:

Now, you are saying is it--withdrawn. On June 29th, in that area, you did not see any discoloration?

# 99 MR. YAMAUCHI:

I'm sorry, that was a question? No, there was nothing that was noticeable.

KEY QUOTE

# 100 MR. SCHECK:

You did not see that area crinkled or puckered in terms of the material?

# 101 MR. HARMON:

Objection, that is beyond the scope.

# 102 THE COURT:

Overruled.

# 103 MR. YAMAUCHI:

Not that I recall.

# 104 MR. SCHECK:

And yesterday, as we--you indicated there were lots of--there were a number of areas cut out of the sock, correct?

# 105 MR. YAMAUCHI:

Yes.

# 106 MR. SCHECK:

And you wrapped it up, you said on redirect examination, and examined the white paper?

# 107 MR. YAMAUCHI:

Afterwards the white paper was laying there and I looked at it, yes.

# 108 MR. SCHECK:

Uh-huh. And yesterday when you looked at the white paper, when you wrapped up the socks with all the cut-outs having been made in the sock, you saw no evidence of any reddish material, little particles on the paper?

# 109 MR. YAMAUCHI:

No, there was nothing obvious. I didn't use a stereomicroscope, but I just visually looked at it and I didn't see anything.

KEY QUOTE

# 110 MR. SCHECK:

And on June 29th when there with no cut-outs in the sock in any area you did not see any reddish particles whatsoever on the white paper?

# 111 MR. YAMAUCHI:

I don't recall.

# 112 MR. SCHECK:

Thank you.

Temperature

tense

Key Quotes (4)

Collin Yamauchi

Well, I don't know if at that time I did or not. Basically what I do is I go through them and I read off and write down my results exactly what I see on the strips, so it might have been at a later time when I went back to analyze it further that I realized that.

Yamauchi admits he may have recorded a result (1.2, 4 for sperm contribution) without understanding at the time what it meant, undermining the reliability of his contemporaneous documentation.

Collin Yamauchi

No, I wouldn't know that because we didn't have a stereomicroscope at the time.

Concedes that the morning's stereomicroscope examination of the sock cannot establish what was present on June 29th, undercutting the prosecution's redirect effort to show blood was always there.

Collin Yamauchi

I'm sorry, that was a question? No, there was nothing that was noticeable.

Confirms he saw no discoloration in the ankle area of the sock on June 29th — the area later found to contain Nicole Brown Simpson's blood — supporting the defense theory of subsequent planting.

Collin Yamauchi

No, there was nothing obvious. I didn't use a stereomicroscope, but I just visually looked at it and I didn't see anything.

After cut-outs were made from the sock the day before testimony, Yamauchi saw no reddish particles on the white paper — consistent with defense argument that blood was deposited in a liquid form rather than dried on the sock from the crime scene.

Evidence (3)

Informal

Mock vaginal swab exercise (September 3, 1993) and hybridization strip results showing 1.2, 4 for sperm cell fraction

challenged — Scheck pressed whether Yamauchi knew at the time of recording that the result was epithelial spillover, not a true sperm contribution

Informal

The sock (Item 13) — dark-colored sock with multiple cut-out areas, examined June 29th and again under stereomicroscope on the morning of testimony

challenged — Scheck established that no discoloration or reddish particles were observed on June 29th, and that the morning stereomicroscope exam cannot speak to that date

Informal

White paper used to wrap the sock after cut-outs were made

discussed — Yamauchi confirmed no reddish material was visible on the paper either from the morning examination or (he couldn't recall) from June 29th

Notable Exchanges (3)

Barry Scheck•Collin Yamauchi

Scheck methodically established that Yamauchi could not say whether he knew, at the moment of recording the 1.2,4 sperm-fraction result on September 3, 1993, that it was actually epithelial spillover. Yamauchi ultimately said he may have realized it only later, at an unknown time, with no notes documenting that realization.

revealing

Barry Scheck•Lance A. Ito

Judge Ito repeatedly tried to curtail the mock vaginal swab line of questioning as not directly relevant to this case, granting Scheck 'one more question' multiple times before finally cutting him off. Scheck pushed each boundary deferentially but persistently.

procedural

Barry Scheck•Collin Yamauchi

Scheck confirmed that on June 29th Yamauchi saw no discoloration and no crinkled or puckered material in the ankle area of the sock, and could not recall seeing reddish particles on the white paper — establishing a baseline inconsistent with blood having been on the sock at initial examination.

strategic

Light Moments (1)

Collin Yamauchi

Yamauchi twice corrected Scheck's 'yesterday' to 'this morning' regarding the stereomicroscope examination, causing a small stumble in Scheck's rhythm.

Credibility Attacks (2)

⚔ Collin Yamauchi

prior inconsistent statement / lack of contemporaneous documentation

Scheck established that Yamauchi had no notes documenting a microscopic sperm cell examination in the mock exercise, could not say when or whether he recognized the 1.2,4 result as epithelial spillover at the time of recording, and never discussed the anomalous result with a supervisor — suggesting his after-the-fact explanations are reconstructed, not contemporaneous.

⚔ Collin Yamauchi

contradiction by omission

Scheck used Yamauchi's own June 29th observations — no visible discoloration, no reddish particles on white paper — against the prosecution's narrative that blood was always present on the sock, implying the blood was added after initial examination.

Witness Demeanor

(No audible response.) — twice, when Scheck asked whether Yamauchi knew at the time of recording that 1.2,4 was epithelial spillover, and when asked whether he knew dark surfaces hide blood

Objections

7 objections (3 sustained, 4 overruled)

Proceeding 6232 • 112 utterances • Prosecution witness

Criminal Trial

Department 103