Cross-examination of Collin Yamauchi (part 2)

📄 Cross-examination of Collin Yamauchi (part 2) — Friday, May 26, 1995

Address:

C:\DEPT103\CRIMINAL\1995\MAY\26\CROSS-EXAMINATION-OF-COLLIN-YA.DOC

TRIAL

▲ Day 83 of 167

◀ Sidebar: validation study documents Return to record with jury ▶

Witness: Collin Yamauchi
Examiner: Barry Scheck
Called by: Prosecution • Date: Friday, May 26, 1995 • Utterances: 118

Barry Scheck continued his cross-examination of LAPD DNA analyst Collin Yamauchi, focusing on the lab's validation studies — specifically mock vaginal swab tests conducted before casework began. Scheck attempted to match Yamauchi's hybridization records (1181-C, D, E) against a code sheet showing expected results (1181-B) to probe whether Yamauchi had actually made incorrect typings he was unaware of, but Yamauchi repeatedly said he would need to return to the lab to verify. The session ended with the judge arranging for Yamauchi to take photocopies over the weekend and check the records himself.

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

# 2 THE COURT:

All right. Thank you, counsel. Proceed.

# 3 MR. SCHECK:

Now, Mr. Yamauchi, I show you what's 1181-A, ask you to look at that document.

# 4 MR. YAMAUCHI:

(The witness complies.) Yes.

# 5 MR. SCHECK:

Now, this document refers to your validation studies?

# 6 MR. HARMON:

Objection, your Honor. Calls for hearsay, no foundation.

# 7 THE COURT:

Sustained.

# 8 MR. SCHECK:

Do you recognize this document?

# 9 MR. YAMAUCHI:

It looks familiar, but I can't say for sure. I'd have to see it in the packets of all the stuff we have.

# 10 MR. SCHECK:

Well, you recall turning over a whole series of documents to the Defense in regard to your validation studies?

# 11 MR. HARMON:

Objection. That misstates the testimony. There's no foundation that he did that either.

# 12 THE COURT:

Overruled.

# 13 MR. YAMAUCHI:

I'm not sure if I did. I believe it might have been my supervisor, Mr. Matheson, that took care of all those things.

# 14 MR. SCHECK:

Well, were you privy or did you know about the documents that were being turned over in regard to validation studies?

# 15 MR. HARMON:

Objection. Compound, calls for hearsay.

# 16 THE COURT:

Overruled.

# 17 MR. YAMAUCHI:

I'm sorry. One more time?

# 18 MR. SCHECK:

Did you know that documents were being turned over in regard to validation studies that you had performed?

# 19 MR. YAMAUCHI:

Yes, I was under that understanding.

# 20 MR. SCHECK:

All right. And you're familiar with the materials that went into those validation studies?

# 21 MR. YAMAUCHI:

Could you be more specific?

# 22 MR. SCHECK:

Yeah. You--first of all, I believe you told us on direct examination that in terms of these tests you received, that as far as you knew, you had either gotten the expected typing at no typeable result, but at no time had you made an incorrect typing result?

# 23 MR. YAMAUCHI:

Yes.

# 24 MR. SCHECK:

And that's what your understanding was after you finished these tests and turned them into your supervisor?

# 25 MR. YAMAUCHI:

After I finished them or--well, I turned in the results and then they come back and tell us, you know, you're okay or you know.

# 26 MR. SCHECK:

They reviewed them with you?

# 27 MR. YAMAUCHI:

Right.

# 28 MR. SCHECK:

And they say you got the right answers?

# 29 MR. YAMAUCHI:

Yes.

# 30 MR. SCHECK:

Either you got the right result or no typing result was observed?

# 31 MR. YAMAUCHI:

That's correct.

# 32 MR. SCHECK:

And at no time did anybody ever tell you that you got a wrong answer?

# 33 MR. YAMAUCHI:

On my validation--I mean my proficiency stuff?

# 34 MR. SCHECK:

And the validation studies?

# 35 MR. YAMAUCHI:

Yes.

# 36 MR. SCHECK:

Okay. Now, one of the validation studies that you did referred to mock vaginal swabs. You recall that, just mentioned that?

# 37 MR. YAMAUCHI:

Yes.

# 38 MR. SCHECK:

Okay. And let me show you what's 1181-C, D and B, ask you to take a look at these documents.

# 39 MR. YAMAUCHI:

(The witness complies.) Yes.

# 40 MR. SCHECK:

Okay. Now, do you recognize 1181-B to be a code, what's known as a code sheet that indicates what the correct types are for the LAPD mock vaginal swab validation tests?

# 41 MR. YAMAUCHI:

There's a listing of types on there, yes.

# 42 MR. SCHECK:

All right. And what 1181-B represents is what the correct results should be for sperm fractions or epithelial cell fractions in the mock vaginal swabs?

# 43 MR. HARMON:

Objection. Calls for hearsay, no foundation.

# 44 THE COURT:

Sustained.

# 45 MR. SCHECK:

Does this represent 1181-B, the code section, statements as to what the correct answer should be for the sperm fraction and the epithelial fraction on the mock vaginal swabs?

# 46 MR. HARMON:

Objection. Calls for speculation, no foundation.

# 47 THE COURT:

Overruled.

# 48 MR. YAMAUCHI:

Okay. It does list typings for a certain set of mock vaginal swabs. I'm not sure if they correspond to this sheet here. I would have to go back and check the records to be sure of that.

# 49 MR. SCHECK:

Uh-huh. Do you have those records here?

# 50 MR. YAMAUCHI:

No. I wasn't told to bring anything except other than that's related to this case.

# 51 MR. SCHECK:

All right. If I show you some records, do you--let me show you some records then.

# 52 (Brief pause.)

# 53 MR. SCHECK:

Now, you recall that the--you've seen these DNA discovery pages; have you not?

# 54 THE COURT:

You're referring to 1181?

# 55 MR. SCHECK:

Yes.

# 56 MR. SCHECK:

In other words, the way they're coded, they have DNA discovery numbers, DNA 586, 587, et cetera? You've seen those before, haven't you?

# 57 MR. YAMAUCHI:

No. I haven't seen that particular numbering system at the top.

# 58 (Brief pause.)

# 59 MR. SCHECK:

Your Honor, I think I--just out of completeness, what I would ask to do is mark another page, 1181-E.

# 60 THE COURT:

You want to show that to Mr. Harmon?

# 61 MR. SCHECK:

Yeah.

# 62 (Deft's 1181-E for id = DNA hybridization record)

# 63 MR. SCHECK:

What I would like you to do is take a look at 1181-C, D and E, okay? My first question to you is, do you recognize those as DNA hybridization records that you filled out?

# 64 MR. YAMAUCHI:

Yes.

# 65 MR. SCHECK:

Those represent your testing and test results?

# 66 MR. YAMAUCHI:

Yes.

# 67 MR. SCHECK:

All right. And there are--in reviewing these, would you confirm that there are 11 different samples tested in 1181-C, D and e?

# 68 MR. YAMAUCHI:

Well, first of all--okay. I can confirm that there are 11 there.

# 69 MR. SCHECK:

All right.

# 70 MR. YAMAUCHI:

Yes.

# 71 MR. SCHECK:

All right. And they're marked v, 11--no. 1-V--no. 1-V to 11-V?

# 72 MR. YAMAUCHI:

Yes.

# 73 MR. SCHECK:

All right. And does that not conform to the 11 mock samples reflected in 1181-B?

# 74 MR. HARMON:

Objection. Calls for speculation, no foundation.

# 75 THE COURT:

Sustained.

# 76 MR. SCHECK:

Do you know if that conforms--withdrawn. On 1181-B, the mock vaginal swabs, are there not 11 different samples that are involved in that test?

# 77 MR. YAMAUCHI:

There's a listing of 11.

# 78 MR. SCHECK:

All right. And comparing 1181-B to 1181-C, D and E, can you not say--well, withdrawn. Comparing 1181-B--

# 79 MR. YAMAUCHI:

Yes.

# 80 MR. SCHECK:

--the 11 mock samples to 1181-C, D and E, does--isn't it true that the hybridization runs that you did are part of this mock vagina swab test?

# 81 MR. HARMON:

Objection. No foundation, calls for hearsay, speculation.

# 82 THE COURT:

Overruled.

# 83 MR. YAMAUCHI:

Okay. To answer that question, I would have to go back to the records to be sure that this set does correspond to this sheet here. As I was explaining earlier, we had to make our own mock vaginal swabs. And part of that had to do with creating some swabs that were typeable and were not so easy that--in other words, we wanted them to be somewhat challenging. Yet, if we made them too challenging, they wouldn't yield results. So in the process of making those, making those samples, we had to run some tests. And I don't know if this is a sheet where we were just making tests to show that the swabs that we were making the swabs to test ourselves with were okay or not. I'd have to go back and look and check.

# 84 MR. SCHECK:

Well, would you compare the expected typing results on these 11 samples from the mock vagina swabs to the results on your sheets?

# 85 MR. HARMON:

Objection. It's irrelevant, no foundation, calls for speculation.

# 86 THE COURT:

Sustained.

# 87 MR. SCHECK:

How would you be able to determine that 1181-C, D and E were part of the mock vaginal swabs that are reflected in the coded material on 1181-B? How could you do that?

# 88 MR. YAMAUCHI:

At this point, I'd have to go back to the lab and examine all our records to be sure that this was in fact the bottom-line finished product that we were using to test ourselves with. This was in a period that was prior to casework. So I'm not sure if it was just times we were practicing or if it was something where we were doing official validation for ourselves.

KEY QUOTE

# 89 MR. SCHECK:

Well--

# 90 MR. YAMAUCHI:

And once again, I was trying to set up some swabs that we could test ourselves with, and that needed testing too.

# 91 MR. SCHECK:

Mr. Yamauchi, just so we're clear, the validation studies included tests that were given to you, mock vaginal swabs before you began casework, right?

# 92 MR. YAMAUCHI:

There were several sets of validation steps and yeah, this was one of them.

# 93 MR. SCHECK:

All right.

# 94 MR. YAMAUCHI:

But like I said before, I have to go back and check to make sure that these two correspond and they're from the same test.

# 95 MR. SCHECK:

Okay. Do you think you can do that? I don't believe we're going to finish this morning. So do you think you can do that over the weekend, you could go back and check and see if these correspond?

# 96 MR. YAMAUCHI:

Yes. That would be fine.

# 97 MR. SCHECK:

Okay. And there's probably no question I could ask you which would help you to see whether or not--

# 98 THE COURT:

I don't think that question is ever going to be right.

# 99 MR. SCHECK:

I'm sorry? I'm sorry?

# 100 THE COURT:

That question has no future.

KEY QUOTE

# 101 MR. SCHECK:

I can tell that has no future.

# 102 MR. SCHECK:

You'll be able to do this, won't you?

# 103 MR. YAMAUCHI:

Can--yeah. Can you leave this with me?

# 104 MR. SCHECK:

I'll--at the end of the day--

# 105 THE COURT:

Actually what we'll do is, we'll give him a photocopy that belongs to the Court.

# 106 MR. SCHECK:

Yes.

# 107 MR. SCHECK:

But as far as you know--

# 108 THE COURT:

Would you have Mr. Gollob make a photocopy of that, please?

# 109 (Brief pause.)

# 110 THE COURT:

Why don't we wait until he does the comparison, then we can save us some time.

# 111 MR. SCHECK:

If you went through the discovery book, you wouldn't be able to do it sitting here. You wouldn't feel comfortable, right? You would want to go back and talk to Mr. Matheson and everybody else in the lab?

# 112 THE COURT:

Mr. Blasier, would you give those things--

# 113 MR. SCHECK:

Is that right?

# 114 MR. HARMON:

Your Honor--

# 115 THE COURT:

That's argumentative.

# 116 MR. HARMON:

Thank you, your Honor.

# 117 THE COURT:

All right. Counsel, given the point, why don't we take our shift at this point. All right. Ladies and gentlemen, we're going to take a brief recess. Please remember my admonitions to you; don't discuss this case amongst yourselves, don't form any opinions about the case, don't allow anybody to communicate with you, don't conduct any deliberations until the case has been submitted to you. We'll stand in recess for 15.

# 118 (Recess.)

Temperature

procedural

Key Quotes (3)

Collin Yamauchi

I'm not sure if it was just times we were practicing or if it was something where we were doing official validation for ourselves.

Yamauchi admits uncertainty about whether his own validation records are official or just practice runs — undermining the reliability of the lab's pre-casework certification.

Lance A. Ito

That question has no future.

A rare moment of dry judicial wit, shutting down Scheck's awkward attempted question mid-formation.

Collin Yamauchi

At this point, I'd have to go back to the lab and examine all our records to be sure that this was in fact the bottom-line finished product that we were using to test ourselves with.

Yamauchi's repeated inability to confirm his own validation results on the stand highlights the defense's argument that LAPD's DNA procedures lacked rigor.

Evidence (3)

Defense 1181-A

Document relating to Yamauchi's validation studies

shown to witness; witness could not confirm recognition with certainty

Defense 1181-B

Code sheet listing correct expected typing results for LAPD mock vaginal swab validation tests

shown to witness and discussed; used as basis for comparison challenge

Defense 1181-C, D, E

DNA hybridization records filled out by Yamauchi showing his actual test results on 11 mock vaginal swab samples

introduced and discussed; Yamauchi confirmed they were his records but could not confirm they matched 1181-B

Notable Exchanges (3)

Barry Scheck•Collin Yamauchi

Scheck pressed Yamauchi to compare his hybridization results to the expected-answer code sheet to expose potential incorrect typings; Yamauchi deflected repeatedly, saying he would need to return to the lab and consult supervisor Matheson.

strategic

Barry Scheck•Lance A. Ito

Judge Ito cut off Scheck's meandering question with 'That question has no future,' drawing laughter and a self-deprecating acknowledgment from Scheck.

light

Lance A. Ito•Barry Scheck•Collin Yamauchi

Judge arranged for Yamauchi to take court photocopies of 1181-B, C, D, E over the weekend to do the comparison himself, effectively pausing the confrontation until Yamauchi could consult records.

procedural

Light Moments (1)

Lance A. Ito

Judge Ito told Scheck mid-question 'That question has no future,' prompting Scheck to agree: 'I can tell that has no future.'

Credibility Attacks (2)

⚔ Collin Yamauchi

competence challenge via validation records

Scheck attempted to use Yamauchi's own hybridization records against the lab's code sheet of expected results to suggest Yamauchi may have produced incorrect typings during validation — contradicting his direct-examination claim of a perfect record. Yamauchi could not refute or confirm this on the stand.

⚔ LAPD DNA Lab

institutional reliability challenge

By exposing that Yamauchi could not identify whether his pre-casework records were 'official validation' or mere practice runs, Scheck cast doubt on whether the lab's certification process was rigorous or well-documented.

Witness Demeanor

(The witness complies.) — twice, when shown documents

Repeatedly hedged answers with 'I'd have to go back and check' and 'I'm not sure'

Asked Scheck 'Can you leave this with me?' when trying to review documents — suggests genuine uncertainty rather than evasion

Objections

10 objections (4 sustained, 4 overruled)

Proceeding 6205 • 118 utterances • Prosecution witness

Criminal Trial

Department 103