Cross-examination of William Shields (part 1)

📄 Cross-examination of William Shields (part 1) — Thursday, June 22, 1995

Address:

C:\DEPT103\CRIMINAL\1995\JUN\22\CROSS-EXAMINATION-OF-WILLIAM-S.DOC

TRIAL

▲ Day 101 of 167

◀ Direct examination of William Shields Cross-examination of William Shields (part 2) ▶

Witness: Dr. William Shields
Examiner: George Clarke
Called by: Defense • Date: Thursday, June 22, 1995 • Utterances: 109

Prosecutor George Clarke cross-examines defense DNA statistics expert Dr. William Shields during a hearing on whether the National Research Council's method for calculating mixture DNA frequencies should be admitted. Clarke systematically works to diminish Shields's credibility relative to prosecution expert Dr. Weir — highlighting that Shields isn't a statistician, ranks himself below Weir by his own informal scale, and stands to be paid $10,000 total by the defense.

# 1 MR. CLARKE:

Yes, thank you, your Honor.

CROSS-EXAMINATION BY MR. CLARKE

# 2 MR. CLARKE:

Dr. Shields, good afternoon.

# 3 DR. SHIELDS:

Good afternoon.

# 4 MR. CLARKE:

I'd like to touch on a couple of the topics that you just discussed while they're fresh in our minds. As far as coincidental identity and laboratory error, it's your belief that those should be incorporated into one figure?

# 5 DR. SHIELDS:

No, it's not.

# 6 MR. CLARKE:

So in fact, is it your testimony that those should be dealt with separately?

# 7 DR. SHIELDS:

Yes, in my opinion.

# 8 MR. CLARKE:

Now, with regard to this particular hearing, is it your understanding that what the Court is making a decision about is whether or not likelihood ratios should be admitted?

# 9 DR. SHIELDS:

No. Well, initially, yes, but I don't think that is anymore.

# 10 MR. CLARKE:

What's your understanding of the issue before this Court in terms of what the Court has to decide?

# 11 DR. SHIELDS:

It's been my understanding both from watching the proceedings and from discussions with attorneys that the decision has to do with whether the National Research Council's method of providing a number for mixtures is useful.

# 12 MR. CLARKE:

Okay. So it's your understanding that what the Court has to decide in this hearing is whether or not the NRC's recommendation is useful?

# 13 DR. SHIELDS:

Yes.

# 14 MR. CLARKE:

If the Court's decision was something different from that, would that impact any of your answers to any of the questions by Mr. Thompson?

# 15 MR. THOMPSON:

Object as to vague.

# 16 THE COURT:

Sustained.

# 17 MR. CLARKE:

As far as likelihood ratios--and you've discussed likelihood ratios in the course of your testimony--is it your testimony that a likelihood ratio is the same as the frequencies that Dr. Weir described on one of the exhibits with the mixture from the steering wheel, item no. 29?

# 18 DR. SHIELDS:

Yes.

# 19 MR. CLARKE:

Now, I'd like if I could, Dr. Shields--first of all, are you a statistician?

# 20 DR. SHIELDS:

I do statistics. I would not count myself as a statistician.

# 21 MR. CLARKE:

Would you consider--first of all, are you familiar with Dr. Weir?

# 22 DR. SHIELDS:

Yes, I am.

# 23 MR. CLARKE:

Is Dr. Weir an individual who is well known in the area of statistics and population frequency data?

# 24 DR. SHIELDS:

Yes, he is.

# 25 MR. CLARKE:

Would it fair to say he's very well known?

# 26 DR. SHIELDS:

Yes.

# 27 MR. CLARKE:

Very well respected?

# 28 DR. SHIELDS:

Absolutely.

# 29 MR. CLARKE:

Your particular area, that is of your Ph.D., is zoology, correct?

KEY QUOTE

# 30 DR. SHIELDS:

No. My Ph.D. was on the evolution of sex in all organisms, and that's population genetics. I was in a zoology department, but it was an evolutionary biology and in particular, population genetic dissertation.

# 31 MR. CLARKE:

Is it correct--and you have a number of publications; is that correct?

# 32 DR. SHIELDS:

That is correct.

# 33 MR. CLARKE:

Is it correct that those or at least the clear majority of those publications are directed towards animals?

# 34 DR. SHIELDS:

No, I wouldn't say a clear majority. I would say it's about half and half.

# 35 MR. CLARKE:

And what would the other half be directed towards?

# 36 DR. SHIELDS:

Population genetic and evolution theory and how they--how they have interactions with each other.

# 37 MR. CLARKE:

Are you a member of any genetic societies?

# 38 DR. SHIELDS:

Yeah. I'm a member of the society of the study of evolution and the American society of naturalists, both of which have large memberships in the areas of genetics.

# 39 MR. CLARKE:

Are you a member of any statistical societies?

# 40 DR. SHIELDS:

No, I am not.

# 41 MR. CLARKE:

As far as your publications--and just briefly, was one of your publications what causes rape, a descending view?

# 42 DR. SHIELDS:

Yes, it was.

# 43 MR. CLARKE:

And was another forcible rape, an evolutionary prospective?

# 44 DR. SHIELDS:

Yes, it is.

# 45 MR. CLARKE:

And another the evolution of sex and examination of current ideas?

# 46 DR. SHIELDS:

Yes.

# 47 MR. CLARKE:

Do you have any peer reviewed articles or publications on statistics and human DNA?

# 48 DR. SHIELDS:

Depends on how you define "Human DNA." The answer is yes. I have paper on the behavioral brain sciences that looks at how genetics, which is how genes, which is DNA, influence human behavior. Parts of my book deal with the distribution of variation in human populations. And in that--from that perspective, the book is also peer review.

# 49 MR. CLARKE:

What about in terms of human DNA as it's used in forensic science?

# 50 DR. SHIELDS:

I have only one non-peer reviewed paper.

# 51 MR. CLARKE:

And you've stated your familiarity with Dr. Weir?

# 52 DR. SHIELDS:

Yes.

# 53 MR. CLARKE:

In your opinion, are you as qualified as Dr. Weir to offer an opinion about the calculation of frequencies with mixed forensic DNA typing stains?

# 54 DR. SHIELDS:

Yes.

# 55 MR. CLARKE:

Do you have a rating system of people involved in the area of DNA and population frequencies?

# 56 DR. SHIELDS:

Not in that area, but in the area of population genetics.

# 57 MR. CLARKE:

Okay. What's that rating system?

# 58 MR. THOMPSON:

Objection. It's irrelevant, your Honor.

# 59 THE COURT:

Overruled.

# 60 DR. SHIELDS:

I wouldn't call it a rating system. In a prior case, during a deposition, I tongue and cheek described how I felt people's representations were in the areas of population genetics, and I used the words "God, demigod and hemigod."

# 61 MR. CLARKE:

God, demigod and hemigod?

# 62 DR. SHIELDS:

Hemigod, yeah.

# 63 MR. CLARKE:

And that was to describe population geneticists?

# 64 DR. SHIELDS:

Yes. They were asking me about the relative reputations of different population geneticists.

# 65 MR. CLARKE:

In Dr. Weir's report in this case--and I believe you said you read that; is that right?

# 66 DR. SHIELDS:

That's correct.

# 67 MR. CLARKE:

He cites an individual named Dr. Crowl; is that right?

# 68 DR. SHIELDS:

Yes.

# 69 MR. CLARKE:

How would you rate Dr. Crowl?

# 70 DR. SHIELDS:

He's at that top level.

# 71 MR. CLARKE:

And the top level again is what?

# 72 DR. SHIELDS:

Again, it's tongue and cheek, but I use the word gods.

# 73 MR. CLARKE:

How do you rate yourself?

# 74 DR. SHIELDS:

Hemigods.

# 75 MR. CLARKE:

How about Dr. Weir?

# 76 DR. SHIELDS:

Demigods.

# 77 MR. CLARKE:

So he is in your view ranked higher than yourself?

# 78 DR. SHIELDS:

In terms of population genetics, yes. But this is not an issue of simply population genetics. It's an issue of logical inference as well, and I think he's wrong and I think I'm right.

KEY QUOTE

# 79 MR. CLARKE:

And you're pretty confident about that?

# 80 DR. SHIELDS:

Yes.

# 81 MR. CLARKE:

Have you read Dr. Weir's publications in the area of forensic DNA typing and population frequencies?

# 82 DR. SHIELDS:

Yes.

# 83 MR. CLARKE:

Do you respect them?

# 84 DR. SHIELDS:

Yes.

# 85 MR. CLARKE:

In terms of this case, have you examined the databases that were used in this case?

# 86 DR. SHIELDS:

Yes.

# 87 MR. CLARKE:

When were you first contacted by the Defense in this case?

# 88 DR. SHIELDS:

July of `94.

# 89 MR. CLARKE:

And have you been working on this case since then?

# 90 DR. SHIELDS:

Depends on how you define working on, but yes, I've interacted with members of the Defense team since then.

# 91 MR. CLARKE:

Can you give us a ballpark estimate of the number of hours you put into this case?

KEY QUOTE

# 92 DR. SHIELDS:

Ballpark estimate. Over 200 hours. Certainly less than 300.

# 93 MR. CLARKE:

And are you charging for that time?

# 94 DR. SHIELDS:

Not by the hour.

# 95 MR. CLARKE:

Well, do you expect to receive--well, have you received any money from the Defense for this case?

# 96 DR. SHIELDS:

Yes. A flat fee.

# 97 MR. CLARKE:

Can you tell us how much that is?

# 98 DR. SHIELDS:

$5,000.

# 99 MR. CLARKE:

Do you anticipate receiving any more money from the Defense?

# 100 DR. SHIELDS:

Yes. One more $5,000 flat fee.

# 101 MR. CLARKE:

You've described seeing, for instance, this chart that's on the easel at the moment where that shows the results of the Bronco automobile. You've said you had seen that previously; is that right?

# 102 DR. SHIELDS:

That's correct.

# 103 MR. CLARKE:

Have you seen all the results charts in this case?

# 104 DR. SHIELDS:

I couldn't possibly be sure of that. A lot of them that I've seen previously have actually been seen from watching on television.

# 105 MR. CLARKE:

Okay. Were you provided reports of the testing laboratories in this case?

# 106 DR. SHIELDS:

Yes, I have.

# 107 MR. CLARKE:

Were you provided raw data from those testing laboratories in terms of bench notes, photographs, et cetera?

# 108 DR. SHIELDS:

I was provided with raw data on the statistical aspects of this case. I have not looked at autorads and I've not looked at strips.

# 109 MR. CLARKE:

So you basically directed your attention towards frequency data as opposed to the science involved in producing exclusions or inclusions?

Temperature

tense

Key Quotes (5)

Dr. William Shields

In a prior case, during a deposition, I tongue and cheek described how I felt people's representations were in the areas of population genetics, and I used the words "God, demigod and hemigod."

Shields's own informal ranking system becomes the vehicle Clarke uses to get him to rank a prosecution-aligned expert above himself

Dr. William Shields

In terms of population genetics, yes. But this is not an issue of simply population genetics. It's an issue of logical inference as well, and I think he's wrong and I think I'm right.

Shields concedes Weir's superior standing in the field but insists he's still correct on the specific statistical method at issue

Dr. William Shields

Can you give us a ballpark estimate of the number of hours you put into this case? Ballpark estimate. Over 200 hours. Certainly less than 300.

Establishes scope of Shields's engagement for the bias/compensation line of cross

Dr. William Shields

$5,000.

Concrete dollar figure for the flat fee Clarke uses to suggest financial bias, with another $5,000 anticipated

George Clarke

Your particular area, that is of your Ph.D., is zoology, correct?

Opening attempt to mischaracterize Shields's credentials as narrower/less relevant than they are, immediately corrected by the witness

Evidence (4)

Informal

Chart on the easel showing DNA testing results from the Bronco automobile

discussed

item no. 29

Mixture sample from the steering wheel, referenced via Dr. Weir's frequency/likelihood-ratio exhibit

discussed

Informal

Dr. Weir's expert report on DNA mixture statistics, which cites Dr. Crowl

discussed

Informal

Raw statistical data from the testing laboratories provided to Shields (he was not given autorads or strips)

discussed

Notable Exchanges (3)

George Clarke•Dr. William Shields

Clarke walks Shields through his own tongue-in-cheek 'god/demigod/hemigod' ranking of population geneticists, getting him to place Dr. Weir above himself before Shields pivots to argue he's still right on the logical-inference issue.

strategic

George Clarke•Dr. William Shields

Clarke establishes Shields's compensation — a $5,000 flat fee already paid and another $5,000 anticipated — plus roughly 200-300 hours on the case, laying groundwork for a bias argument.

strategic

George Clarke•Dr. William Shields

Clarke presses on Shields's academic credentials, getting him to concede his publications are about half animal-focused and include papers on the evolutionary theory of rape, and that he has only one non-peer-reviewed paper specific to forensic human DNA.

strategic

Light Moments (1)

Dr. William Shields

Shields describes his self-deprecating, 'tongue and cheek' rating scale of population geneticists as 'God, demigod and hemigod,' ranking a well-known colleague above himself.

Credibility Attacks (3)

⚔ Dr. William Shields

bias via compensation

Clarke elicits that Shields received a $5,000 flat fee from the defense and expects another $5,000, after roughly 200-300 hours of work, to suggest financial interest in his opinion.

⚔ Dr. William Shields

qualification comparison / impeachment by self-ranking

Clarke gets Shields to admit he is not a statistician and, using Shields's own informal 'god/demigod/hemigod' scale, to rank prosecution-aligned expert Dr. Weir ('demigod') above himself ('hemigod').

⚔ Dr. William Shields

publication/credential association

Clarke highlights that only about half of Shields's publications concern humans, that he has essentially one non-peer-reviewed paper on forensic human DNA, and surfaces his authorship of papers on the evolutionary theory of rape.

Objections

2 objections (1 sustained, 1 overruled)

Proceeding 6516 • 109 utterances • Defense witness

Criminal Trial

Department 103