Redirect examination of Collin Yamauchi (afternoon)

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

Address:

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

TRIAL

▲ Day 85 of 167

◀ Recross-examination of Collin Yamauchi (afternoon) Witness preparation ▶

Witness: Collin Yamauchi
Examiner: Rockne Harmon
Called by: Prosecution • Date: Wednesday, May 31, 1995 • Utterances: 35

Harmon conducts a brief redirect to neutralize Scheck's earlier cross-examination about differential extraction and sperm/epithelial cells, getting Yamauchi to confirm that none of those techniques were relevant to the blood evidence he actually tested. Scheck responds with a final recross pressing the point that mixture interpretation is inherently difficult regardless of sample type, trying to undercut confidence in Yamauchi's blood mixture results.

# 1 THE COURT:

Mr. Harmon.

FURTHER REDIRECT EXAMINATION BY MR. HARMON

# 2 MR. HARMON:

Mr. Yamauchi, I just have a few questions. We spent about a half our talking about sperm and epithelial cells and mock vaginal swabs, okay?

# 3 MR. SCHECK:

Motion to strike, colloquy.

# 4 THE COURT:

Sustained. Just ask a question.

# 5 MR. HARMON:

Mr. Yamauchi, do you have any reason to believe that there was any sperm on 78, the bottom of Mr. Goldman's shoe?

# 6 MR. SCHECK:

Objection, irrelevant.

# 7 THE COURT:

Overruled.

# 8 MR. YAMAUCHI:

No.

# 9 MR. HARMON:

Do you have any reason to believe that there was any sperm on the Defendant's steering wheel where item no. 21 was removed from?

# 10 MR. SCHECK:

Objection, beyond the scope of recross and irrelevant.

# 11 THE COURT:

Overruled.

# 12 MR. YAMAUCHI:

No.

# 13 MR. HARMON:

Do you have any reason to believe that there was any sperm on item 117, the rear gate at Bundy on the outside?

# 14 MR. YAMAUCHI:

No.

# 15 MR. HARMON:

Does the subject of sperm and epithelial cells and differential extraction have anything to do with the work that you performed in this case?

# 16 MR. SCHECK:

Objection.

# 17 THE COURT:

Legal ground.

# 18 MR. SCHECK:

Irrelevant.

# 19 THE COURT:

Overruled.

# 20 MR. YAMAUCHI:

The differential extraction process was--was not performed. We did the regular blood extraction process, so it has nothing to do with the work that I did on this case.

# 21 MR. HARMON:

Okay. Thanks, Mr. Yamauchi. No further questions, your Honor.

FURTHER RECROSS-EXAMINATION BY MR. SCHECK

# 22 MR. SCHECK:

Mr. Yamauchi, doesn't getting correct results with mixtures have everything to do with the work you did on this case?

# 23 MR. HARMON:

Objection. It is argumentative, your Honor.

# 24 THE COURT:

Overruled.

# 25 MR. YAMAUCHI:

Yes, you want to get correct results.

# 26 MR. SCHECK:

And if anything, in terms of the arsenal of tools that a forensic scientist has available to sort out mixtures, isn't it easier to do vaginal swabs that are mixture of sperm and epithelial cells than it is to do bloodstains that have contributions from two or more people?

# 27 MR. HARMON:

Objection, asked and answered. It is beyond the scope. It is irrelevant.

# 28 THE COURT:

Overruled. I assume this is the last question?

# 29 MR. SCHECK:

Yes.

# 30 MR. YAMAUCHI:

Okay. For--or one thing, if you are talking about the process--this question is actually two questions. If you are talking about the process, the differential extraction is more complicated, so that is harder to perform. But if you are talking about interpretations, mixtures are always difficult. Sexual assault cases--they are inherent in sexual assault cases so that is a part of that type of work. If you have a mixture with a blood case, the same thing, interpretations will become more difficult.

# 31 MR. SCHECK:

Isn't interpretation easier in a sexual assault case because you have the ability to do differential extractions and you can literally visualize the sperm cells under a microscope?

# 32 MR. HARMON:

Objection. It is irrelevant, it is beyond the scope.

# 33 THE COURT:

Overruled.

# 34 MR. YAMAUCHI:

That is an important tool, but because it is not perfect, the same--the same problems exist in interpretation as far as mixtures are concerned.

KEY QUOTE

# 35 THE COURT:

All right. Mr. Yamauchi, thank you very much, sir. You are excused now as a witness. And Mr. Harmon, do we have Mr. Sims available?

Temperature

procedural

Key Quotes (3)

Collin Yamauchi

The differential extraction process was not performed. We did the regular blood extraction process, so it has nothing to do with the work that I did on this case.

Harmon's payoff line — Yamauchi confirms Scheck's extended cross about sexual assault forensics was irrelevant to the actual blood evidence in this case.

Collin Yamauchi

If you have a mixture with a blood case, the same thing, interpretations will become more difficult.

Scheck extracts a concession that blood mixture interpretation carries the same difficulties as sexual assault cases — keeping doubt alive about the reliability of Yamauchi's results.

Collin Yamauchi

That is an important tool, but because it is not perfect, the same problems exist in interpretation as far as mixtures are concerned.

Scheck's final point: even with additional visualization tools, mixture interpretation is never clean — leaving ambiguity over Yamauchi's blood mixture analysis.

Evidence (3)

Item 78

Bottom of Ron Goldman's shoe

Discussed — Yamauchi confirms no sperm present

Item 21

Swab from OJ Simpson's Bronco steering wheel

Discussed — Yamauchi confirms no sperm present

Item 117

Rear gate at Bundy (outside)

Discussed — Yamauchi confirms no sperm present

Notable Exchanges (2)

Rockne Harmon•Collin Yamauchi

Harmon systematically walks through key blood evidence items asking whether sperm was present, then lands the cleanup question establishing differential extraction had no bearing on Yamauchi's actual work.

strategic

Barry Scheck•Collin Yamauchi

Scheck pivots to argue that blood mixture interpretation is just as hard as sexual assault mixture interpretation — even without differential extraction — trying to preserve the doubt he had planted on cross.

strategic

Credibility Attacks (1)

⚔ Collin Yamauchi

scope creep / analogy argument

Scheck argues that the complexity of interpreting mixtures — demonstrated through the sexual assault swab analogy — applies equally to the blood mixture work Yamauchi performed, implying his results should be viewed with the same skepticism.

Objections

7 objections (1 sustained, 5 overruled)

Proceeding 6233 • 35 utterances • Prosecution witness

Criminal Trial

Department 103