📄 Sidebar: witness expertise — Tuesday, May 9, 1995
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C:\DEPT103\CRIMINAL\1995\MAY\9\SIDEBAR-WITNESS-EXPERTISE.DOC
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▲ Day 70 of 167

Sidebar: witness expertise

Date: Tuesday, May 9, 1995 • Utterances: 11
Defense attorney Peter Neufeld objected at sidebar that the prosecution's expert witness — qualified as a microbiologist — lacked the foundational expertise to testify about statistical methods for calculating match probabilities across multiple DNA loci. Neufeld argued that population genetics and statistics are distinct disciplines requiring separate qualification. Prosecutor George Clarke countered that the witness had testified on frequency data in 90 cases and that California case law supported her qualifications. Judge Ito overruled the objection.
1 THE COURT:

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

2 (The following proceedings were held at the bench:)
3 THE COURT:

All right. We're at sidebar. Mr. Neufeld.

4 MR. NEUFELD:

Okay. My concern is this. She is certainly an expert in the area of microbiology. I'm not challenging that. She's even entitled to report on frequencies for a particular allele because there's data in the laboratory, and she can testify to that as business records. But now she's being asked as an expert to testify to what methods are used to calculate a probability, a cross multiple loci. That has nothing to do with a Frye hearing. It has nothing to do with what the law is in California. It has to do with no foundation that she has the expertise to testify to what are the appropriate methods for calculating a probability of cross loci. That has to come from somebody who has either the expertise in statistics or expertise in population genetics. And no foundation has been laid that this witness has that expertise. When she testifies as an expert, she can't borrow the expertise of another witness.

And so one of the concerns I had even before, for instance, was on certain articles she had read. Although an expert can rely on hearsay and publications to help her develop her opinion, it has to be a threshold finding, that she is in fact an expert in that particular discipline. And we don't want to confuse the different disciplines here. Expertise that enables somebody to be an expert and give statistical testimony is different than the expertise that comes from being a microbiologist and testifying about genetic variation and how to do these gels and the like. And I don't believe that foundation has been laid, and that's why I object to her testifying as to the actual method for calculating the probability of cross loci.

5 THE COURT:

Mr. Clarke.

6 MR. CLARKE:

Your Honor, I couldn't disagree more. I have in my hand sections of five California cases that deal with the issue of qualifications at trial as far as general acceptance hearing, Frye, dealing with statistics, which is a fraction of this witness' qualifications even to talk about frequency data, and I have those if the Court would like to see them. But at this point, this witness has described her background, her training since 1988 at this point as well as the fact that she has qualified as an expert in by far the majority of her 90 cases presenting frequency data. So I think when the Court takes all this and in combination particularly with the case law in California, that this witness far exceeds the threshold needed to be able to testify as an expert on population frequency data in front of a jury.

7 MR. NEUFELD:

Two things very briefly. One is, I believe there are instances in fact where her expertise has been rejected by a Court of law. Number two, we know that from the record in those other--in that particular--

8 THE COURT:

Keep your voice down.

9 MR. NEUFELD:

Certainly. In that particular discipline of population genetics. And, number two, how do know that lawyers in the other cases didn't make the same objection I'm making with the same factual record? I mean that's the problem with citing some of those other cases. The point is, I don't believe at this point in time, they've laid adequate foundation. It is as simple as that.

10 THE COURT:

All right. Objection overruled.

11 (The following proceedings were held in open Court:)

Temperature

tense

Key Quotes (4)

Peter Neufeld
When she testifies as an expert, she can't borrow the expertise of another witness.
Core principle of Neufeld's objection — that being a microbiologist does not confer expertise in population genetics or statistics, and those are legally distinct disciplines.
Peter Neufeld
Expertise that enables somebody to be an expert and give statistical testimony is different than the expertise that comes from being a microbiologist and testifying about genetic variation and how to do these gels and the like.
Draws the clearest line of his argument: the witness can testify about lab work but not about the mathematical methods used to derive match probabilities.
George Clarke
This witness has described her background, her training since 1988 at this point as well as the fact that she has qualified as an expert in by far the majority of her 90 cases presenting frequency data.
Clarke's rebuttal centers on practical courtroom qualification — 90 prior cases is a strong record of accepted expertise.
Peter Neufeld
How do we know that lawyers in the other cases didn't make the same objection I'm making with the same factual record?
Undercuts Clarke's reliance on prior cases by pointing out that prior admission doesn't mean the objection was properly raised — a sharp procedural counter.

Notable Exchanges (2)

Peter NeufeldGeorge Clarke
Neufeld argued the witness lacked foundation to testify about cross-loci probability methods, distinguishing microbiology from population genetics. Clarke responded with California case law citations and the witness's 90-case track record. Neufeld then challenged the precedential value of those cases by noting the same objection may not have been raised in them.
strategic
Lance A. ItoPeter Neufeld
Judge Ito admonished Neufeld to keep his voice down during the sidebar — a small procedural reminder of the physical constraints of the setting.
procedural

Credibility Attacks (1)

⚔ prosecution DNA expert witness
challenge to expertise foundation
Neufeld argued the witness's qualifications as a microbiologist do not extend to population genetics or statistical methodology for calculating match probabilities across multiple loci, and that courts have previously rejected her expertise in that specific discipline.

Objections

1 objections (0 sustained, 1 overruled)
Proceeding 5973 • 11 utterances
Criminal Trial
Department 103
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📂 MAY 9, 1995 📄 Sidebar: witness expertise
MAY 9, 1995 KRT DvH TD