📄 Direct examination of Dr. Terence Speed (part 1) — Monday, August 7, 1995
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Direct examination of Dr. Terence Speed (part 1)

Witness: Dr. Terence Speed
Examiner: Peter Neufeld
Called by: Defense • Date: Monday, August 7, 1995 • Utterances: 496
Defense statistics expert Professor Terence Speed of UC Berkeley testified about the limitations of the prosecution's DNA frequency statistics, arguing they fail to account for laboratory error rates, evidence handling mistakes, or contamination. Drawing extensively from the National Research Council (NRC) report, Speed contended that error rates must be disclosed to juries alongside match probabilities, and directly disagreed with prosecution experts Weir and Cotton who both dismissed the relevance of error rates.
1 (The following proceedings were held in open court, in the presence of the jury:)
2 THE COURT:

All right. Thank you, ladies and gentlemen. Please be seated. Mr. Neufeld.

3 MR. NEUFELD:

Thank you.

4 THE COURT:

You may call the next witness.

5 MR. NEUFELD:

At this time, Defense calls Professor Terence Speed.

6 THE COURT:

All right. Dr. Speed.

Terence Speed, called as a witness by the Defendant, was sworn and testified as follows:

7 THE COURT:

Right next to the court reporter there, face the clerk.

8 THE CLERK:

Raise your right hand, please. You do solemnly swear that the testimony you may give in the cause now pending before this court shall be the truth, the whole truth, and nothing but the truth, so help you God?

9 DR. SPEED:

I do.

10 THE CLERK:

Please have a seat on the witness stand and state and spell your first and last names for the record.

11 DR. SPEED:

My name is Terence, T-E-R-E-N-C-E, Paul Speed, S-P-E-E-D.

12 THE CLERK:

Thank you.

13 THE COURT:

Mr. Neufeld.

14 MR. NEUFELD:

Thank you, your Honor. Good afternoon, ladies and gentlemen.

THE JURY: Good afternoon.

DIRECT EXAMINATION BY MR. NEUFELD

15 MR. NEUFELD:

Well, Professor Speed, you've already given us your name. Where do you live?

16 DR. SPEED:

In Berkeley, California.

17 MR. NEUFELD:

Okay. And could you please tell the ladies and gentlemen of the jury what your occupation is and what positions you hold?

18 DR. SPEED:

Umm, I'm a professor of statistics, the University of California at Berkeley.

19 MR. NEUFELD:

And could you, please, for the ladies and gentlemen of the jury summarize your education?

20 DR. SPEED:

I received a bachelor's degree in science majoring in mathematics and statistics at a University in Melbourne, Australia, and later a Ph.D. majoring in mathematics at another university, Monish University also in Australia.

21 MR. NEUFELD:

And could you also summarize your professional appointments since the time you received your Ph.D.?

22 DR. SPEED:

Okay. After I got my Ph.D., I went to the United Kingdom, worked for about four years at the University of Sheffield. And I went back to Australia, worked for nine years as a professor in mathematics at the University of Western Australia. Then I left academia for a few weeks and had a job in a government laboratory as chief of a group of mathematicians and statisticians, and that was about eight years ago. I left there and went to the University of California, Berkeley, where I've been ever since.

23 MR. NEUFELD:

Now--one moment. Let's back up a second. You said that you taught at the University of Western Australia?

24 DR. SPEED:

That's correct.

25 MR. NEUFELD:

And while you were at the University of Western Australia, did you have a particular title at some point during that time?

26 DR. SPEED:

Yes. Towards the end of my period there, I was chair of the department of mathematics.

27 MR. NEUFELD:

And you also mentioned, sir, that--excuse me--Professor, that you took some time off and you worked for something called the division of mathematics and statistics?

28 DR. SPEED:

Right. That's--

29 MR. NEUFELD:

Could you explain what that is?

30 DR. SPEED:

That's a division of an organization with a very long title which I'll give, commonwealth scientific and industrial research organization, which is a very large multi-disciplinary organization spread all around Australia, doing research in those areas, and I had a division of mathematics and statistics with about a hundred mathematicians and statisticians again located all around Australia, and I was the chief of that group.

31 MR. NEUFELD:

You weren't something one of the hundred in that department. You were actually the chief of it?

32 DR. SPEED:

That's correct.

33 MR. NEUFELD:

Okay. And you mentioned that currently you are a Professor at the University of California at Berkeley. Is that referred to as Cal or Berkeley? What's the easiest way for me to refer to it for the future so I can defer? Is it Cal?

34 DR. SPEED:

UC Berkeley. It's pretty brief.

35 MR. NEUFELD:

Okay. All right. During the time that you were at the University of California at Berkeley in the statistics department, were you ever made the chairman of that department?

36 DR. SPEED:

Yeah. I was chair for four years, 1989 to `93, and then I went on a sabbatical and gave up the chair.

37 MR. NEUFELD:

Could you tell the jury and myself and other counsel in the court, what is statistics?

38 DR. SPEED:

Well, a one-line definition might be something like this. That is the use of numerical information or it's the art and science of using numerical information to answer questions of interest to people.

39 MR. NEUFELD:

Can you give us some examples of statistics?

40 DR. SPEED:

Yeah. One example might be, why does the casino always win at roulette? Another one might be, how do I design an experiment to test whether a new drug or a new medical treatment is better or not better than an existing one? A third one might be, how do we design sampling procedures so we can predict the outcome of something like an election with a very, very small number of people, just a few thousand out of a country the size of the United States.

41 MR. NEUFELD:

Can you give us some--I'm sorry. Are you aware of any examples of where good statistics are used to overthrow the--some accepted, but nevertheless erroneous view?

42 DR. SPEED:

Certainly. There's lots in the medical area where new medical techniques and in former days, new drugs, became available, and without proper testing, were found by the proponents to be effective. Yet, when well-designed statistically valid studies were conducted, they were found to be ineffective. So it's now quite commonly used to screen drugs, not quite as commonly used to screen surgical procedures and other medical inventions.

43 MR. NEUFELD:

All right. Are you a member of any professional organizations within the field of statistics?

44 DR. SPEED:

Yeah. Lots.

45 MR. NEUFELD:

Okay. Are any of those--why don't you summarize if you could.

46 DR. SPEED:

Well, I'm a member of statistical societies, the major ones in the United States, which are the American Statistical Association and the Institute of Mathematical Statistics, remain active in the Australian Statistical Society and one in the United Kingdom and another one, the Biometric Society.

47 MR. NEUFELD:

You mentioned the Institute of Mathematical Statistics. What is that?

48 DR. SPEED:

Well, that's the professional organization of people with a somewhat more theoretical vent, mathematical statistics, rather than just statistics.

49 MR. NEUFELD:

And have you been elected to any executive body in that organization?

50 DR. SPEED:

Yeah. I'm a member of the council of that body.

51 MR. NEUFELD:

Is that the governing council?

52 DR. SPEED:

Yeah.

53 MR. NEUFELD:

And you also mentioned that you were a member of the Biometric Society. What is the Biometric Society, Professor?

54 DR. SPEED:

Well, that's the society of people who are interested in applying statistics to biology and medicine.

55 MR. NEUFELD:

And have you held any office in that organization?

56 DR. SPEED:

Yeah. I've had the presidency of one of the regions. The--that's a worldwide society which is divided up I think into about 10 regions, and for a period a few years ago, I was the president of one of the regions.

57 MR. NEUFELD:

And by the way, the Biometric Society which you said is involved in the interface of statistics and biology and medicine, does it also involve the application of statistics to genetics?

58 DR. SPEED:

Certainly.

59 MR. NEUFELD:

And by genetics, I mean, does it also involve the application of statistics to DNA typing?

60 DR. SPEED:

Yeah. I think genetics these days includes molecular genetics, which is pretty much things related to DNA.

61 MR. NEUFELD:

And are you also a member of the triple AS?

62 DR. SPEED:

That's correct.

63 MR. NEUFELD:

And what does that stand for, sir?

64 DR. SPEED:

That's the American Association for the Advancement of Science.

65 MR. NEUFELD:

And do you have any particular status in that organization?

66 DR. SPEED:

Well, I have been elected to a fellowship of that organization.

67 MR. NEUFELD:

So is that an organization anyone can just join or does it require an election?

68 DR. SPEED:

Anyone can just join, but you have to be elected to be a fellow.

69 MR. NEUFELD:

Now, are you a currently--are you currently a member of any advisory body which focuses on human genetics research?

70 DR. SPEED:

Yeah. I'm a member of the--what's called the human geno study group formed by the national institutes of health.

71 MR. NEUFELD:

Could you please tell us what that is, sir?

72 DR. SPEED:

Well, as people may know, there is a thing going on these days called the human geno project, which is a very detailed study of DNA in a typical human, and there's a whole institute of the national institutes of health divided to research and promoting the broad study of that area; and they give away many millions of dollars each year to researchers around the world, but mainly in the United States, and the greatest--or the proposals that come in are assessed by a study group of which I am a member.

73 MR. NEUFELD:

Now, other than your appointments in these various organizations, Professor, have you served on the editorial boards of any peer review journals in your field?

74 DR. SPEED:

Yeah. I've served on the editorial board of most of the major journals in my field, although right now I'm only--I've got off most of them recently and I'm on only one at the moment.

75 MR. NEUFELD:

And aside from your editorial appointments, Professor, have you authored any technical papers in the field of statistics?

76 DR. SPEED:

Yes, I have.

77 MR. NEUFELD:

Approximately how many?

78 DR. SPEED:

I think it's, you know, about a hundred, 120. I'd have to just have a glance. Yeah. I think up to about 120.

79 MR. NEUFELD:

Could you please tell us a little bit what these papers are about and how they've evolved over the years?

80 DR. SPEED:

Well, shortly after I did my Ph.D., most of them were somewhat theoretical in nature, but over the last decade or so, I've got increasingly involved in the application of statistics to a variety of disciplines, but primarily biology and more recently genetics.

81 MR. NEUFELD:

And even before you became involved in the field of probabilities in genetics and in DNA typing, were you involved--did you--I'm sorry--did you write a paper on nuclear reactor accidents?

82 DR. SPEED:

I did.

83 MR. NEUFELD:

And did that paper involve the likelihood that certain errors can occur which can cause a nuclear mishap?

84 DR. SPEED:

Yes. That was--it was a critique of a big study conducted by what is now called the nuclear regulatory commission to try to find the accident--the probability of risks of an accident from a commercial nuclear reactor.

85 MR. NEUFELD:

And in your opinion, was your work on that paper at all related to any of the issues that you're going to be testifying to today?

86 DR. SPEED:

Well, in the general sense that that paper was a critique of the statistics that was used in that study. I was very critical of the study because in my view, it misused statistics quite badly, and to some extent, there was an element of that in the use of statistics in DNA profiling. To that extension, there's a similarity.

87 MR. NEUFELD:

Over the last four or five years, approximately how many articles have you authored on the application of statistics to genetics?

88 DR. SPEED:

I think it would be about 20.

89 MR. NEUFELD:

Now, you're not a forensic scientist, are you?

90 DR. SPEED:

I am not.

91 MR. NEUFELD:

Do you believe you need to be a forensic scientist before you can give an expert opinion on the application of statistics to forensic DNA profiling?

92 DR. SPEED:

I certainly hope not, because if that were the case, you would have to be professional in any discipline to which statistics was applied before you could come forward, and that's not the way things work.

93 MR. NEUFELD:

How do things work, doctor?

94 DR. SPEED:

Well, if a statistician is going to make comments on the use of statistics in another discipline, then obviously they need to be familiar to some extent with that other discipline and, in particular, to be able to appreciate the way statistics is being used. They certainly don't have to be professionals in that discipline. If they were, they wouldn't be statisticians.

95 MR. NEUFELD:

Now, how did you become interested in the application of statistics to forensic DNA profiling?

96 DR. SPEED:

Well, the interest in statistics and genetics is long-standing, and I think it was around 1990, there was a one-day symposium on actually that topic, statistics in DNA identification done here in L.A., and I and a few students came down and attended it and we got our first taste of the subject.

97 MR. NEUFELD:

As a result of that first taste on the subject five years ago, did you continue to do reading and thinking and participating in scholarly discussion about that subject?

98 DR. SPEED:

Yes, I did.

99 MR. NEUFELD:

Have you been asked at any time during the last five years to actually become involved in criminal cases involving the application of statistics to forensic DNA profiling?

100 DR. SPEED:

Yes, I have.

101 MR. NEUFELD:

And approximately how many times have you become involved in cases of that nature other than this case?

102 DR. SPEED:

Twice.

103 MR. NEUFELD:

And in those two cases where you became involved, did you consult for the Defense or the Prosecution?

104 DR. SPEED:

Both cases involved public defender.

105 MR. NEUFELD:

And in both of those cases, sir, did you charge a fee for your expert work?

106 DR. SPEED:

No, I didn't.

107 MR. NEUFELD:

So in neither of them, did you charge a fee?

108 DR. SPEED:

That's correct.

109 MR. NEUFELD:

Okay. And in the course of working on those cases, did you have an opportunity to review database autorads produced by a DNA laboratory?

110 DR. SPEED:

I did.

111 MR. NEUFELD:

Which laboratory was that?

112 DR. SPEED:

Well, we made a visit to Quantico, which is where the FBI research, DNA research operation is based.

113 MR. NEUFELD:

Now, in addition to those two cases that you were involved in, have you remained interested in the issue?

114 DR. SPEED:

Yes. I certainly have.

115 MR. NEUFELD:

Have you organized and/or attended any statistics--statistics conference sessions devoted to the forensic issues?

116 DR. SPEED:

Yes, I have.

117 MR. NEUFELD:

By the way, have you ever been approached by law enforcement to become involved in this issue to assist the Prosecution?

118 DR. SPEED:

I have.

119 MR. NEUFELD:

And when was that and where was that, Professor?

120 DR. SPEED:

I think it was about spring 1993, I got a call from the people at the Berkeley lab, which is referred to here as DOJ.

121 MR. NEUFELD:

Would that be the same laboratory that Gary Sims works at?

122 DR. SPEED:

Yes.

123 MR. NEUFELD:

Okay. And could you please tell us what happened?

124 DR. SPEED:

Well, I was just invited to come and look around the lab and chat with people because they had heard, presumably through my involvement with these cases, that I'm interested in the subject. So we--I looked around and we exchanged views.

125 MR. NEUFELD:

And at that time with that meeting at the Department of Justice laboratory, did you share your thoughts and criticisms of the statistical applications being used at the laboratory?

126 DR. SPEED:

Yeah, I did. I got the impression that they would have liked me to--

127 MR. HARMON:

Objection. Nonresponsive.

128 THE COURT:

Sustained.

129 MR. NEUFELD:

Now, aside from that experience you had at the DOJ laboratory when they invited you there to view their laboratory work and then to discuss these issues with them, have you ever on any other occasion assisted law enforcement?

130 DR. SPEED:

Yes.

131 MR. NEUFELD:

And could you please tell us when that was?

132 DR. SPEED:

Uh, I think it was early 1993, I was approached by people from--well, they were based in the Alameda County District Attorney's office, but one of the people was a federal Prosecutor I believe.

133 MR. NEUFELD:

And to your knowledge by the way, Professor Speed, is Mr. Harmon here a member of the Alameda County District Attorney's office?

134 DR. SPEED:

I believe so.

135 MR. NEUFELD:

Okay. Please go ahead, sir.

136 DR. SPEED:

Well, they were working on a case involving the possibility of the sale of contaminated meat in a supermarket chain, that being quite a number of tests proved to be positive for contamination, and I wanted to organize a sampling plan to see if this was systematic and not just occasional contamination.

137 MR. NEUFELD:

And so did law enforcement at that time use your expertise in the field of statistics to help them design the appropriate study for the Prosecution?

138 DR. SPEED:

They did.

139 MR. NEUFELD:

By the way, when you did that work for the Alameda County District Attorney's office back in 1993, did you--were you--did you personally receive any compensation for that work?

140 DR. SPEED:

No.

141 MR. NEUFELD:

Would I be correct in saying, Professor, that this is actually though your first time testifying in a court of law on the forensic application of DNA?

142 DR. SPEED:

That's correct.

143 MR. NEUFELD:

Are you a little bit nervous? No? Okay. Now, you mentioned that in the two times where you assisted the Defense, that you didn't charge any compensation and you mentioned at the time you assisted the Prosecution in their case, that you didn't charge any fee as well. In this case, are you accepting any fee, any money at all in exchange for your time and your expertise and your testimony?

144 DR. SPEED:

No.

145 MR. NEUFELD:

Now, Professor, are you familiar with Dr. Bruce Weir, who testified in this case as a Prosecution witness?

146 DR. SPEED:

I am.

147 MR. NEUFELD:

Has Dr. Weir ever sought your input on his writing on statistical applications of forensic DNA issues?

148 DR. SPEED:

Yeah, he has.

149 MR. NEUFELD:

Now, Dr. Weir testified that he had no background in forensic science and no training in forensic science. Do you have any training at all in that area?

150 DR. SPEED:

No.

151 MR. NEUFELD:

After you became involved in this case, Professor, did you review any of the testimony of different witnesses?

152 DR. SPEED:

I did.

153 MR. NEUFELD:

And which testimony have you reviewed?

154 DR. SPEED:

I've reviewed Dr. Weir's, I've reviewed Mr. Sims', I've reviewed Dr. Cotton's and I've seen some of the testimony from the LAPD of Mr. Yamauchi. So--

155 MR. NEUFELD:

Have you also--are you also familiar with the testimony that Dr. Gerdes gave during the last several days?

156 DR. SPEED:

Yes. I've been watching and I've been present for some of it.

157 MR. NEUFELD:

Have you reviewed any of the open proficiency test data that these laboratories talked about?

158 DR. SPEED:

I have.

159 MR. NEUFELD:

Have you reviewed Dr. Weir's report and the calculations contained therein?

160 DR. SPEED:

Yes.

161 MR. NEUFELD:

By the way, Professor, have you written a report for this case?

162 DR. SPEED:

I have not.

163 MR. NEUFELD:

Have you been asked to make any calculations in regard to this case?

164 DR. SPEED:

No.

165 MR. NEUFELD:

Now, other than reviewing the materials that you described, have you met with the lawyers to discuss these issues?

166 DR. SPEED:

I have.

167 MR. NEUFELD:

On a number of occasions?

168 DR. SPEED:

Yeah. On three occasions I think, three or four over several months.

169 MR. NEUFELD:

And what, if anything else, have you done to prepare yourself for your testimony today?

170 DR. SPEED:

Well, basically read lots and lots of stuff, talk to people and think about it.

171 MR. NEUFELD:

As an expert in the field of statistics, Professor, is it the case that sometimes people misinterpret the meaning of a statistical statement?

172 DR. SPEED:

I think that's very frequent.

173 MR. NEUFELD:

How does it happen or can you give examples of it?

174 DR. SPEED:

Well, I think when people make statements, particularly statements about probabilities or frequencies, it's often unclear just what is the event, the precise event, whose probability or whose frequency is being spoken of. It's also often clear what is the assumptions under which this calculation is being made, and how the calculation is being made is also relevant, and that's very rarely something people know.

175 MR. NEUFELD:

Professor, have you seen small Xerox copies of the various evidence boards that have been prepared by the Prosecution? And I'll just use this as--for illustrative purposes, the--

176 THE COURT:

It's the Bronco result board.

177 MR. NEUFELD:

Yeah. Just put it up for a second. And I put up the People's item no. 260.

178 MR. NEUFELD:

Okay. Have you seen reduced Xerox copies of this board?

179 DR. SPEED:

Yes.

180 MR. NEUFELD:

Okay. And have you also seen reduced Xerox copies of the other boards for Rockingham DNA profiling, Bundy DNA profiling and the glove DNA profiling?

181 DR. SPEED:

Yeah. I have them.

182 MR. NEUFELD:

Now, let me ask you this apropos of what you just said, sir, about the meaning of statistical statements. For instance, are the frequencies reflected on the last column on these evidence boards, are they the probability of Mr. Simpson's guilt or innocence?

183 DR. SPEED:

No, they're not.

184 MR. NEUFELD:

Are the frequencies on these evidence boards the probability that someone other than Mr. Simpson is the source of any particular stain?

185 DR. SPEED:

No, they're not.

186 MR. NEUFELD:

What do these numbers tell the jury about the probability of a false or misleading match being reported due to errors in the collection and handling of samples?

187 DR. SPEED:

Nothing.

188 MR. NEUFELD:

What do these numbers tell us about the probability of a false or misleading--I'm sorry. What do these numbers tell us about the probability of a false or misleading match being reported due to evidence tampering?

189 DR. SPEED:

Nothing.

190 MR. NEUFELD:

Are these numbers on the boards relevant if the matches are determined to be due to cross-contamination?

191 DR. SPEED:

If the match has been determined to be, then no. Not relevant at all.

192 MR. NEUFELD:

Now, are you familiar, sir, with Dr. Robin Cotton's testimony about her reporting of how Cellmark did on the California Association open proficiency testing? Do you recall that?

193 DR. SPEED:

I do.

194 MR. NEUFELD:

And do you recall when she testified that with respect to one of the batches of 50 samples that they received, that--there was a match that she gave as a--gave a frequency for of 1 in 1.8 billion? Do you remember that?

195 DR. SPEED:

I do.

196 MR. NEUFELD:

And do you remember her testimony when she said that later on, the submitting agency told her that they had a false positive? Do you recall that, sir?

197 DR. SPEED:

I do.

198 MR. NEUFELD:

And do you recall her then saying that having learned that it was a false positive, that the statistic of 1 in 1.8 billion was irrelevant? Do you remember that?

199 DR. SPEED:

I do.

200 MR. NEUFELD:

And do you agree with that?

201 DR. SPEED:

I do, yes.

202 MR. NEUFELD:

Now, what, if anything, do these frequencies tell us about the probability that swatches were mixed up at the Los Angeles Police Department?

203 DR. SPEED:

They tell you nothing.

KEY QUOTE
204 MR. NEUFELD:

I can put this down now.

205 THE COURT:

Why don't you let Mr. Harris handle it.

206 MR. NEUFELD:

Thanks. Sorry.

207 MR. NEUFELD:

Now, Professor, Dr. Cotton, Mr. Sims and Dr. Weir have each given their own opinion as to how rare particular DNA profiles are in this case. Are you familiar with their testimony?

208 DR. SPEED:

Yes.

209 MR. NEUFELD:

In order to assess the evidentiary significance of these DNA typings, are there other frequencies that are also important?

210 DR. SPEED:

I believe so.

211 MR. NEUFELD:

And I think you said that you're also familiar with the testimony of Dr. Gerdes regarding the various opportunities to err in this case?

212 DR. SPEED:

I am, yes.

213 MR. NEUFELD:

Now, when you're thinking about the other frequencies which would also be important to consider, is it also too important--I'm sorry--is it also important from a statistical standpoint to consider the chance that the reported matches are the result of error in crime scene collection and packaging?

214 DR. SPEED:

I believe so.

215 MR. NEUFELD:

Is it important to consider from a statistical standpoint the chance that the reported matches are the result of error when the evidence is unpacked at the Los Angeles Police Department?

216 DR. SPEED:

Yes.

217 MR. NEUFELD:

Is it important to consider from a statistical standpoint the chance that the reported matches are the result of error when the evidence is put into bindles on the next morning?

218 DR. SPEED:

Yes.

219 MR. NEUFELD:

Is it important from a statistical standpoint to consider the chance that the reported matches are the result of error when the Bundy drops and Mr. Simpson's reference sample are processed by Mr. Yamauchi?

220 MR. HARMON:

Objection. Leading, argumentative.

221 THE COURT:

Leading.

222 MR. NEUFELD:

What, sir, would be the importance--well, is there any importance at all to--from a statistical standpoint to assessing the chance that reported matches are the result of error when the Bundy drops and Mr. Simpson's reference sample are processed by Mr. Yamauchi at the LAPD?

223 MR. HARMON:

Objection. Leading.

224 THE COURT:

Overruled.

225 DR. SPEED:

Yes. All stages in the process are relevant to assessing this chance.

226 MR. NEUFELD:

Now, again, from a statistical standpoint, is it important to consider the chance that the reported matches are the result of error in the DNA testing laboratory, for instance?

227 DR. SPEED:

Yes.

228 MR. NEUFELD:

Is it also important to consider the chance that a reported match is a true match, but that the source is someone other than Mr. Simpson, but someone who has the same DNA profile of him at the loci that had been studied?

229 MR. HARMON:

Objection. Compound, leading.

230 THE COURT:

Compound. Rephrase the question.

231 MR. NEUFELD:

Okay. From a statistical standpoint, is it important to consider the chance that a reported match is a true match?

232 DR. SPEED:

Yes.

233 MR. NEUFELD:

Okay. And is it important to consider that--from a statistical standpoint, that the source of that match is someone other than Mr. Simpson, but that someone is simply someone who has the same DNA profile as Mr. Simpson?

234 DR. SPEED:

Yes. That's a fact that's true.

235 MR. NEUFELD:

And in fact, Professor, in response to that last question, that the Prosecution experts listed those frequencies in the final column of those various boards?

236 MR. HARMON:

Objection. Leading.

237 THE COURT:

Sustained. Rephrase the question.

238 MR. NEUFELD:

Well, do the frequencies on those boards address that last question?

239 DR. SPEED:

Yes. As far as I can see, that's the only question that those frequencies speak to.

240 MR. NEUFELD:

From a statistical standpoint, Professor, is it important to consider the chance that it may really be Mr. Simpson's blood, but that the drops were left by Mr. Simpson at some earlier date?

241 MR. HARMON:

Objection. That's vague as to which drops.

242 THE COURT:

Sustained.

243 MR. NEUFELD:

Okay. From a statistical standpoint, if you were to consider simply for the purpose of this question, the Bundy--the Bundy drops on the walkway, sir, would it be important to consider the chance that it may really be Mr. Simpson's blood on that walkway, but that those drops were left by Mr. Simpson at an earlier date?

244 MR. HARMON:

Objection. That's calls for speculation, that you can quantify that.

245 THE COURT:

Sustained.

246 MR. NEUFELD:

From a statistical standpoint, is it important to consider the chance of various alternative hypotheses to explain certain data?

247 MR. HARMON:

Objection. Calls for speculation, no foundation.

248 THE COURT:

Overruled.

249 DR. SPEED:

Yes.

250 MR. NEUFELD:

And is that something that is within the field of statistics?

251 DR. SPEED:

I believe so.

252 MR. NEUFELD:

Okay. Are you familiar with Dr. Weir's testimony where he said that all of his calculations assume the validity of all the DNA testing done in this case?

253 DR. SPEED:

Yes.

254 MR. NEUFELD:

From a statistical standpoint, is Dr. Weir's assumption scientifically appropriate in your opinion?

255 DR. SPEED:

I don't believe so.

256 MR. NEUFELD:

And why not?

257 DR. SPEED:

Well, I believe that the possibility of errors can never be ruled out and, therefore, there is an incompleteness in any evaluation that is based on the assumption that no errors could have happened.

258 MR. NEUFELD:

Now, Professor, are these views criticizing Dr. Weir's position just yours or have you considered the opinions of other experts in reaching your conclusions on this point?

259 MR. HARMON:

Objection. Calls for speculation, hearsay, no foundation.

260 THE COURT:

Foundation.

261 MR. NEUFELD:

All right. In reaching your opinion that you just gave about Dr. Weir's conclusion, did you consider the report issued by the national research council of the national academy of science?

262 DR. SPEED:

I did.

263 MR. NEUFELD:

And which portions--

264 MR. NEUFELD:

One moment.

265 (Discussion held off the record between Defense counsel.)
266 MR. NEUFELD:

By the way, Professor, are you aware of the views of other experts in your field on this particular issue that I just addressed?

267 DR. SPEED:

I certainly am, yeah.

268 MR. NEUFELD:

And have you considered the views of other experts in helping to reach your opinion that you're providing this jury with today on the witness stand?

269 DR. SPEED:

I have.

270 MR. NEUFELD:

And I believe you said that one source that you have considered in giving your testimony today are the conclusions of the national research council, the national academy of science; is that correct?

271 DR. SPEED:

That's correct.

272 MR. NEUFELD:

And could you please tell us which portions of this book, of this report that you considered in helping to frame your position on the witness stand today?

273 DR. SPEED:

Well, I've read--you mean the actual pages?

274 MR. NEUFELD:

Well, could you please tell us the first--can you give us a page reference, please?

275 DR. SPEED:

Well, perhaps I'll start with the very first one, which is a page that doesn't actually have a number. That is opposite the contents page. It's a discussion there of errors.

276 THE COURT:

Mr. Neufeld, let's do this by question and answer rather than having the doctor read it from the book.

277 MR. NEUFELD:

Okay.

278 MR. NEUFELD:

All right. Professor, could you turn to page 160 first. In reaching your opinions as an expert on these issues involving the statistical applications to forensic DNA profiling, have you considered the following quote? Reading from the bottom of page 160. Quote--

279 MR. HARMON:

Well, your Honor, I don't think it's appropriate. If he says no, then the content of that's not--

280 THE COURT:

Sustained.

281 MR. NEUFELD:

All right. Would you please look at the paragraph beginning at the bottom of page 160 and ending at the top of 161.

282 DR. SPEED:

Yes.

283 MR. NEUFELD:

Is that one of the quotes that you have considered and taken into account in helping to develop your opinion that you're giving on the witness stand today?

284 DR. SPEED:

It certainly is.

285 MR. NEUFELD:

May I now? Thank you.

286 MR. NEUFELD:

And I'm quoting now from the NRC report at the bottom of page 160. Quote: "Expectations regarding the parallel of DNA typing can lead to overlooking or ignoring sources of error or mistakes in applying the technology. For example, jurors focusing on the probability of correctly identifying a perpetrator might lead them to discount the possibility of laboratory error, whether it stems from incompetence or carelessness of personnel, malfunctioning equipment or unavoidable mistakes." Did I read that accurately?

287 DR. SPEED:

I believe so.

288 MR. NEUFELD:

Okay. Sir, what is the meaning of that quote?

289 DR. SPEED:

Well, I think it says that you should be conscious not just of the frequencies of the particular multilocus genotypes that are quoted, but also be aware of the possibility of errors in the--of the kinds that have been stated and the frequencies with which these errors might occur and contribute to a wrongful result.

290 MR. NEUFELD:

Would you please put up slide 1.

291 MR. NEUFELD:

Now, referring you specifically to different sections of this report, have you considered--I'm sorry. You began to say before that you considered the--a portion of the preface or prefatory language?

292 DR. SPEED:

Yes.

293 MR. NEUFELD:

Now, I call your attention, sir, to the page directly preceding the table of contents.

294 DR. SPEED:

I have it.

295 MR. NEUFELD:

In the third paragraph, did you consider--in helping to develop your own opinion on these matters, consider that first sentence in the third paragraph?

296 DR. SPEED:

I did.

297 MR. NEUFELD:

Would you please put up slide 2.

298 MR. NEUFELD:

Now, sir--and can you see it from where you're sitting?

299 DR. SPEED:

I can.

300 MR. NEUFELD:

Okay.

301 THE COURT:

Excuse me, doctor. If you look, there's a monitor right to your right.

302 DR. SPEED:

Oh, thanks.

303 THE COURT:

Avoid neck strain.

304 MR. NEUFELD:

Now, the report says that, quote: "We regard the accreditation and proficiency testing of DNA typing laboratories as essential to the scientific accuracy, reliability and acceptability of DNA typing evidence in the future." By the way, do you know when the--this report was published?

305 DR. SPEED:

I believe it was April 1992.

306 MR. NEUFELD:

Okay. And, sir, could you please explain what is meant by that statement?

307 DR. SPEED:

Well, that the authors of the report think it important that agencies that do DNA testing get accredited and participate in proficiency testing. Otherwise, the scientific accuracy, reliability and acceptability might be compromised.

308 MR. NEUFELD:

Have you also considered the language that appears on page 88?

309 DR. SPEED:

Yes.

310 MR. NEUFELD:

And the specific portion that I'm referring to--one moment--beginning with the second paragraph on the page.

311 DR. SPEED:

Yep.

312 MR. NEUFELD:

And is that one of the portions of this report that you have considered in reaching your opinions today on the witness stand?

313 DR. SPEED:

I certainly have.

314 MR. NEUFELD:

Could you please put up slide 4.

315 MR. NEUFELD:

Okay. Now, I'm going to ask you if you agree with the following quote from the NRC report. "Interpretation of DNA typing results depends not only on population genetics, but also on laboratory error. Two samples might show the same DNA pattern for two reasons: Two persons have the same genotype at the loci studied or the laboratory has made an error in sample handling procedure or interpretation. Coincidental identity and laboratory error are different phenomena. So the two cannot and should not be combined in a single estimate. However, both should be considered." What are the authors saying at this point, Professor?

316 MR. HARMON:

Objection. Calls for speculation.

317 THE COURT:

Sustained.

318 MR. NEUFELD:

Well, how does this quote affect your own opinion on this particular issue?

319 DR. SPEED:

Well, it states very strongly that in addition to the frequencies that are associated with coincidental match, there should be some estimate of frequency of errors, the different kinds.

320 MR. NEUFELD:

And why is that?

321 DR. SPEED:

Because both can contribute to an incorrect conclusion about the source of a DNA profile or the source of a stain.

322 MR. NEUFELD:

Now, sir, in addition to that paragraph, paragraph on page 88, did you also--can I call your attention to page 89? And I call your attention to the first paragraph. Is that a paragraph or portion of this report that you have considered in the development of your own opinions that you're giving on the witness stand today?

323 DR. SPEED:

Yes.

324 MR. NEUFELD:

Okay.

325 MR. NEUFELD:

Could you please put up slide 5.

326 MR. NEUFELD:

I'm quoting from page 89: "Especially for a technology with high--" I'm sorry. "Especially for a technology with high discriminatory power such as DNA typing, laboratory error rates must be continually estimated in blind proficiency testing and must be disclosed to juries. For example, suppose the spans of a match due to two persons having the same pattern were 1 in 1 million, but the laboratory had made one error in 500 tests. The jury should be told both results. Both facts are relevant to a jury's determination." In your opinion, sir, are both facts relevant to a jury's determination?

327 DR. SPEED:

I believe so.

328 MR. NEUFELD:

And why is that?

329 DR. SPEED:

Because, as I said earlier, there are two different ways in which incorrect conclusions can be reached. One is a chance coincidental match and the other is that the result could be as a result of laboratory error.

330 MR. NEUFELD:

And, sir, again, in helping to develop your opinions of this particular matter, did you also consider page 15?

331 DR. SPEED:

Yes, I did.

332 MR. NEUFELD:

And I'm referring specifically to the second paragraph on the page.

333 DR. SPEED:

Yes.

334 MR. NEUFELD:

Could you please put up slide 3.

335 (Discussion held off the record between Defense counsel.)
336 MR. NEUFELD:

Your Honor, before we go any further, I have been reminded by Mr. Cochran that I did not ask for a number for this for the next in order. It's my recollection that this exhibit was shown to someone else.

337 THE COURT:

You're actually reading this into the record. So it's in the record.

338 MR. HARMON:

May we approach, your Honor, because I think Mr. Neufeld has spoken some interesting words. May we approach, your Honor?

339 THE COURT:

No.

340 MR. HARMON:

Well, I'd like to discuss what he just said and what he told me before we started, your Honor.

341 THE COURT:

At a later point. Proceed.

342 MR. HARMON:

Reading from page--

343 MR. HARMON:

Have these previously been marked, your Honor?

344 THE COURT:

No, they have not. You want to mark it as an exhibit, continuing exhibit?

345 MR. NEUFELD:

We can mark it as an exhibit.

346 MR. HARMON:

Your Honor, may we approach?

347 THE COURT:

No. Proceed.

348 MR. NEUFELD:

Referring you now to page 15, and I quote from the section. It says: "Laboratory error rates should be measured with appropriate proficiency tests and should play a role in the interpretation of results of forensic DNA typing." Do you agree with that statement?

349 DR. SPEED:

I do.

350 MR. NEUFELD:

And what does that statement mean to you?

351 DR. SPEED:

It means that there should be appropriate proficiency tests where appropriate remains to be defined for establishing laboratory error rates which then should be available for interpreting the results of forensic DNA testing.

352 MR. NEUFELD:

And, sir, finally, referring you to page 89--

353 MR. NEUFELD:

One moment.

354 (Brief pause.)
355 MR. NEUFELD:

Referring you now to the third paragraph on the page, have you considered that portion of the report also of the national research counsel in helping you develop your own opinion on these matters?

356 DR. SPEED:

I have.

357 MR. NEUFELD:

And now with the Court's permission, I'll put up slide 6, please.

358 MR. NEUFELD:

And again, Professor, I'm quoting from the national research council's report, page 89, where it states, quote: "Reported error rates should be based on proficiency tests that are truly representative of case materials with respect to sample quality, accompanying description, et cetera." What does that--first of all, do you agree with that?

359 DR. SPEED:

I do.

360 MR. NEUFELD:

And what does it mean to you, sir?

361 DR. SPEED:

Well, it means that the reported or the error rates that should be reported should be based on proficiency tests which are in as many ways as possible similar to actual cases.

362 MR. NEUFELD:

For instance, in this case, have you heard testimony that samples were degraded?

363 DR. SPEED:

I have.

364 MR. NEUFELD:

And you've also reviewed the testimony of Dr. Cotton and Mr. Sims; have you not?

365 DR. SPEED:

I have.

366 MR. NEUFELD:

And also of Collin Yamauchi with respect to proficiency testing that they've had at their three laboratories?

367 DR. SPEED:

I have.

368 MR. NEUFELD:

When they describe the type of proficiency tests that they had, did they state that they were using samples that were representative of casework?

369 DR. SPEED:

No. Not in my opinion.

370 MR. NEUFELD:

Okay. Did they--in any way, did they acknowledge--

371 MR. HARMON:

Objection. No foundation for his opinion on that. Move to strike.

372 THE COURT:

Overruled. Foundation though.

373 MR. NEUFELD:

Are you familiar with the testimony of Dr. Cotton, Mr. Sims and Mr. Yamauchi that they did not have degraded samples in their proficiency tests?

374 DR. SPEED:

I am.

375 MR. HARMON:

Objection. Calls for hearsay, no foundation.

376 THE COURT:

Sustained. Answer is stricken.

377 MR. NEUFELD:

Your Honor, I have the page citations.

378 THE COURT:

Proceed.

379 MR. NEUFELD:

All right.

380 MR. NEUFELD:

Does the NRC report declare elsewhere the necessity of relying on external blind proficiency testing?

381 DR. SPEED:

They do.

382 MR. HARMON:

Objection. That calls for hearsay, your Honor.

383 THE COURT:

Overruled.

384 MR. NEUFELD:

I call your attention to page 106 and 107 of the NRC report.

385 THE COURT:

Aren't we getting redundant at this point?

386 MR. NEUFELD:

This is the last one, your Honor, and I'm out of the report.

387 MR. NEUFELD:

Do you agree, sir, with the statements expressed by the authors of the NRC report contained at the bottom of page 106 and the top of 107?

388 DR. SPEED:

I do.

389 MR. NEUFELD:

And in those statements, sir, does it talk about the necessity of external blind proficiency testing?

390 DR. SPEED:

It does.

391 MR. NEUFELD:

Oh, by the way, from a statistical standpoint, Professor, why is it necessary that laboratory error rates be calculated on the basis of external blind proficiency tests administered on a continuing basis?

392 MR. HARMON:

Objection. Calls for speculation, no foundation.

393 THE COURT:

Overruled.

394 MR. NEUFELD:

Well, let's start at the beginning. Why is it--I'm sorry. Why is it essential that they be external proficiency tests?

395 DR. SPEED:

Well, I think that's so that the tests will have credibility, so that there will be uniformity in their application, so that the results can be widely disseminated and also, in fact, so that they can be fully blind. It's rather hard to imagine blind in the sense that we're talking about, tests which are internal.

396 MR. NEUFELD:

Okay. And by the way, does the NRC report define what they mean by "Blind external proficiency testing"?

397 DR. SPEED:

They do.

398 MR. NEUFELD:

And what is the definition given?

399 DR. SPEED:

Well, external--

400 MR. HARMON:

Objection. No foundation.

401 THE COURT:

Sustained.

402 MR. NEUFELD:

Do you agree with the definition given by the national research council in their report?

403 MR. HARMON:

Objection. No foundation.

404 THE COURT:

Overruled.

405 DR. SPEED:

I do agree with the definition.

406 MR. NEUFELD:

And what is the definition that they give?

407 DR. SPEED:

Well, "External" means, of course, that the agency doing the proficiency testing is separate from the body that's being tested. "Blind" means that the people in the organization being tested are not aware that the samples they are processing, the test samples, are any different from any other samples that they are processing in their normal casework.

408 THE COURT:

Are we about to wind this up? I mean, this is the fifth witness who's told us about the difference between blind and open proficiency testing.

KEY QUOTE
409 MR. NEUFELD:

Moving on from blind and external, why is it essential that the testing be done on a continual basis?

410 DR. SPEED:

Well, for a start, if people make errors, then they should obviously take steps to correct them so such errors don't occur in the future. So that you need a continuing program of testing so that you see that the corrective measures you took are actually working. And also, of course, your error rate may be going down if things are getting better. So you want the most readable, up to date estimate of your error rate.

411 MR. NEUFELD:

Can you give examples of external blind proficiency testing to calculate laboratory error rates in other applications?

412 DR. SPEED:

Yes, I can. I mean, they use--

413 MR. NEUFELD:

All right. Are you familiar with Dr. Gerdes' testimony regarding the national marrow donor program in which his laboratory participates?

414 DR. SPEED:

Yes, I am.

415 MR. NEUFELD:

Is the kind of external blind proficiency testing that they do one example?

416 DR. SPEED:

It is.

417 MR. NEUFELD:

Are you familiar with the use of external blinds in urine testing for the presence of illegal drugs by any governmental agency in this country?

418 DR. SPEED:

Yes, I am.

419 MR. NEUFELD:

And what agency does that to your knowledge?

420 DR. SPEED:

Well, the federal highway administration does it and I think a number of others do. They certainly do.

421 MR. NEUFELD:

And do you know how it's accomplished?

422 DR. SPEED:

Well, the urine samples are tested for illegal drugs by accredited testing organizations, and the samples should be sent to them by the people, you know, by the employers of the drivers, and they're instructed how many samples that they should include that will be blind to the testing agency, which will either have no drugs or there will be some that are spiked to have specific drugs; and then the test will be whether the testing agency actually detects the ones that have no blood--no drugs and finds the appropriate drugs in the ones that have been spiked with drugs.

423 MR. NEUFELD:

By the way, even outside the fields of chemical analysis, are there other examples that you can think of where external blind proficiency testing is utilized in a similar way?

424 DR. SPEED:

Yes. I've made it in the mining area where if you go out and do some prospecting and you have some samples that you think contain valuable ore, you're going to send them off to a chemical laboratory for analysis to say, for example, gold or silver or copper, then you're very interested in whether you got accurate determinations of the concentrations of these samples. So it's very, very common in that area to include samples with known concentrations out of a whole variety of levels so that you can have a check with your unknown samples on the laboratory doing the work. And the laboratory, of course, doesn't know which are the new samples and which are the known samples. This is quite routine in the mining industry.

425 MR. NEUFELD:

In this particular case, are you aware that Dr. Weir testified that he rejects the notion of an error rate, page 33--

426 MR. HARMON:

Misstates the testimony, calls for hearsay, speculation.

427 THE COURT:

Sustained.

428 MR. NEUFELD:

Have you--

429 MR. NEUFELD:

One moment.

430 (Discussion held off the record between Defense counsel.)
431 MR. NEUFELD:

Sir, are you familiar with Dr. Bruce Weir's testimony in this case?

432 DR. SPEED:

I have read it.

433 MR. NEUFELD:

Did you review that portion of Dr. Weir's testimony where he gave his--I'm sorry--where he gave his opinion on the relevance of error rates in forensic DNA profiling?

434 DR. SPEED:

I saw it, yes.

435 MR. NEUFELD:

And what was the opinion that he gave?

436 MR. HARMON:

Objection. Calls for hearsay.

437 THE COURT:

Overruled.

438 DR. SPEED:

Well, I believe he stated that he rejects the notion of an error rate.

KEY QUOTE
439 MR. NEUFELD:

And, sir, did you also read--review Dr. Cotton's testimony on the same subject?

440 DR. SPEED:

I did.

441 MR. NEUFELD:

And what was Dr. Cotton's opinion as best you can recall on the same question?

442 DR. SPEED:

This is not as I precisely recall, but I believe she said, "I made errors in the past and I don't make them anymore."

KEY QUOTE
443 MR. NEUFELD:

Let me--

444 MR. HARMON:

Your Honor, I object. That calls for speculation. That's not what she said. That misstates the testimony.

445 THE COURT:

Overruled. The jury heard what Dr. Cotton said as with Dr. Weir.

446 MR. HARMON:

Move to strike the answer.

447 THE COURT:

Overruled. The jury can compare the two and see if there's a difference that's significant.

448 MR. NEUFELD:

One moment.

449 (Brief pause.)
450 MR. NEUFELD:

May I approach the witness to show him a portion of testimony?

451 THE COURT:

Proceed.

452 MR. NEUFELD:

Thank you.

453 MR. HARMON:

Excuse me. May I please see that?

454 MR. NEUFELD:

Sure.

455 MR. HARMON:

Can I see it over here?

456 (Brief pause.)
457 MR. NEUFELD:

It's 27471.

458 MR. NEUFELD:

Are you familiar with the opinion that Dr. Cotton gave on the role of laboratory error rates in evaluating the weight of DNA evidence?

459 DR. SPEED:

Yes.

460 MR. NEUFELD:

And what was her opinion?

461 DR. SPEED:

That it should play no role.

462 MR. NEUFELD:

Now, sir, do you agree with that opinion of Dr. Cotton?

463 DR. SPEED:

I don't, no.

464 MR. NEUFELD:

Do you agree with that opinion of Dr. Weir?

465 DR. SPEED:

No.

466 MR. NEUFELD:

Now, in your opinion, sir, does the NRC report also disagree with the opinions of Dr. Weir and Dr. Cotton on that point?

467 MR. HARMON:

Objection. Calls for a conclusion, speculation, no foundation.

468 THE COURT:

Sustained.

469 MR. NEUFELD:

Well, as an expert who is asked to interpret those portions of the report that deal with statistical issues, what is your opinion as to whether the NRC report rejects or disagrees with the opinions of Bruce Weir and Robin Cotton?

470 MR. HARMON:

That misstates the sections that--

471 THE COURT:

Sustained.

472 MR. NEUFELD:

Well, does the NRC report endorse the use of error rates based on external blind proficiency testing as a necessity for interpreting forensic DNA profiling?

473 DR. SPEED:

That's how I read the report.

474 MR. NEUFELD:

Are there other experts besides the NRC report whose opinions you have considered as well?

475 MR. HARMON:

Objection. Calls for hearsay, no foundation.

476 THE COURT:

Overruled.

477 DR. SPEED:

Yes, there are.

478 MR. NEUFELD:

Maybe we should approach at this moment, your Honor.

479 THE COURT:

Proceed.

480 MR. NEUFELD:

Okay. In the field of statistics as opposed to--I'm sorry--withdrawn. In the field of statistics as applied to genetics, who would those other experts be whose opinions on this matter you have listened to?

481 MR. HARMON:

Objection. The names, your Honor--it's clear where we're going. This calls for hearsay, no foundation.

482 THE COURT:

Overruled.

483 DR. SPEED:

Well, a number of professors of statistics that I know who are interested in or knowledgeable about genetics.

484 MR. NEUFELD:

And could you please tell us the names of those people whose opinions you considered?

485 MR. HARMON:

Your Honor, objection. This is where we discussed before we--

486 THE COURT:

Are those notes you're referring to, doctor?

487 DR. SPEED:

Well, I have them. I can cite them without referring to the notes.

488 MR. HARMON:

I have not been provided a copy of those despite my repeated request, your Honor.

489 THE COURT:

Proceed.

490 MR. HARMON:

May I have a copy of those notes? I've never seen them, your Honor.

491 THE COURT:

Have a seat. We'll take that up shortly.

492 MR. NEUFELD:

Would you please tell us the names of the experts in the field of statistics as applied to genetics whose opinions you have considered on this particular question?

493 DR. SPEED:

Dr. David Balding, the Queen Mary College in London.

494 MR. HARMON:

I'm sorry?

495 DR. SPEED:

Dr. David Balding, B-A-L-D-I-N-G, Professor Peter Donnelly of the University of Chicago, D-O-N-N-E-L-L-Y, Professor Elizabeth Thompson of the University of Washington in Seattle.

496 THE COURT:

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

Temperature

procedural

Key Quotes (5)

Dr. Terence Speed
Nothing.
Speed's repeated one-word answer to what the prosecution's DNA frequency statistics tell us about the probability of false matches due to errors, contamination, or tampering — devastating in its simplicity
Dr. Terence Speed
I believe he stated that he rejects the notion of an error rate.
Speed characterizing Weir's position, setting up his rebuttal that this view contradicts the NRC report and statistical best practices
Dr. Terence Speed
This is not as I precisely recall, but I believe she said, 'I made errors in the past and I don't make them anymore.'
Speed's characterization of Cotton's position on error rates — Harmon objected strenuously but was overruled, and Ito noted the jury could compare the two accounts
Peter Neufeld
Especially for a technology with high discriminatory power such as DNA typing, laboratory error rates must be continually estimated in blind proficiency testing and must be disclosed to juries.
NRC report quote read into the record, forming the backbone of Speed's testimony that prosecution experts violated accepted standards
Lance A. Ito
Are we about to wind this up? I mean, this is the fifth witness who's told us about the difference between blind and open proficiency testing.
Ito's visible impatience with the defense's repetitive proficiency-testing testimony

Evidence (4)

People's 260
Bronco DNA result board showing DNA frequencies in final column
displayed and discussed to illustrate what the statistics do and do not prove
Informal
Prosecution DNA evidence boards for Rockingham, Bundy, and glove DNA profiling
discussed; Speed testified the frequency columns address only coincidental match probability, nothing else
Informal
NRC (National Research Council) report, pages cited: preface, 15, 88, 89, 106-107, 160-161
extensively quoted; introduced as slides; formed the primary basis for Speed's opinions on error rates and proficiency testing requirements
Informal
California Association open proficiency test data from Cellmark, LAPD, and DOJ laboratories
discussed in context of whether labs used degraded or case-representative samples

Notable Exchanges (4)

Peter NeufeldDr. Terence Speed
Series of rapid-fire questions about what the DNA frequency statistics do NOT tell the jury — errors, tampering, contamination, mix-ups — each answered 'Nothing' or 'Not relevant at all'
strategic
Rockne HarmonLance A. Ito
Harmon repeatedly sought sidebar on NRC report exhibits, was denied each time; Ito twice told him 'No' and to proceed, then later allowed it 'at a later point'
tense
Lance A. ItoPeter Neufeld
Ito interrupted to note this was 'the fifth witness' to explain blind versus open proficiency testing, signaling court fatigue with the defense's repeated expert testimony on this point
procedural
Rockne HarmonLance A. Ito
Harmon moved to strike Speed's characterization of Cotton's testimony; Ito overruled and told jury they could compare the two accounts themselves
revealing

Light Moments (3)

Peter Neufeld
Neufeld asked Speed if he was nervous testifying for the first time in court; Speed apparently shook his head or looked unperturbed, prompting Neufeld to move on: 'No? Okay.'
Lance A. Ito
Ito advised Speed to use the monitor to his right rather than crane his neck at the projection screen: 'Avoid neck strain.'
Dr. Terence Speed
Speed deflected Neufeld's question about whether to call his employer 'Cal' or 'Berkeley': 'UC Berkeley. It's pretty brief.'

Credibility Attacks (2)

⚔ Dr. Bruce Weir
expert opinion rebuttal
Speed testified that Weir's assumption of zero error probability is statistically inappropriate and contradicted by the NRC report; directly quoted Weir as having 'rejected the notion of an error rate'
⚔ Dr. Robin Cotton
expert opinion rebuttal
Speed testified Cotton's position that error rates 'should play no role' in evaluating DNA evidence weight is one he disagrees with, and she herself acknowledged a prior false positive at 1 in 1.8 billion that rendered the statistic irrelevant

Objections

22 objections (11 sustained, 11 overruled)
Proceeding 7201 • 496 utterances • Defense witness
Criminal Trial
Department 103
⚖️ Start
📂 AUG 7, 1995 📄 Direct examination of Dr. Tere
AUG 7, 1995 KRT DvH TD