📄 Redirect examination of Dr. John Gerdes (afternoon, part 2) — Monday, August 7, 1995
Address:
C:\DEPT103\CRIMINAL\1995\AUG\7\REDIRECT-EXAMINATION-OF-DR-JOH.DOC
TRIAL
▲ Day 130 of 167

Redirect examination of Dr. John Gerdes (afternoon, part 2)

Witness: Dr. John Gerdes
Examiner: Barry Scheck
Called by: Defense • Date: Monday, August 7, 1995 • Utterances: 159
Barry Scheck conducted redirect examination of Dr. John Gerdes, the defense's DNA contamination expert, following cross-examination by George Clarke. Scheck used a series of slides (Defense 1314-A through G) to walk the jury through specific LAPD proficiency test failures showing contamination that caused incorrect DNA typing and was not detected by negative controls. Scheck also rehabilitated Gerdes on his credentials and motivations, rebutting Clarke's attacks on his forensic experience, financial bias, and unusual career path.
1 (Deft's 1314-A through 1314-G for id = slides)
2 MR. SCHECK:

Now, could you please explain to the jury what this data represents?

3 DR. GERDES:

Well, this is the 7-14-93 proficiency samples, and on that particular date, the female reference sample no. 1 was typed by LAPD as a 1.3, 4 and the correct type is a 1.2, 4.

4 MR. SCHECK:

Now, what is the--what does it say? No. 8, negative control, what does that represent?

5 DR. GERDES:

The control that's supposed to be a negative control, it should have no DNA whatsoever, in this case, showed the indication of DNA, and that DNA was typeable as including 1.2 and 4 alleles.

6 MR. SCHECK:

All right. Can we have the next slide, please, which will be 1314-B.

7 MR. SCHECK:

What does this indicate?

8 DR. GERDES:

Well, the type--the LAPD type was a 1.3, 4. The alleles that were found on the negative control included a 1.2, 4, and from that, we can conclude that the 1.3 was not depicted on the negative control.

9 MR. SCHECK:

Now, in other words, you're saying this means that there was contamination that caused an incorrect type here that was not detected by the negative control?

10 DR. GERDES:

That's correct.

11 MR. SCHECK:

Now, in your review of the LAPD lab in your study of contamination of runs and contamination of strips, in how many instances did you detect contamination that was not picked up by the negative control? In other words, the negative control was blank, but you nonetheless saw contamination.

12 DR. GERDES:

28 percent of the times.

KEY QUOTE
13 MR. SCHECK:

Now, let's go to the--then this represents the typing by Erin Riley on 7-14?

14 DR. GERDES:

Correct.

15 MR. SCHECK:

Now, you remember Mr. Clarke asked you questions about what would you--did Erin Riley do the right thing when she typed it again, and you said yes, correct?

16 DR. GERDES:

Yes.

17 MR. SCHECK:

But at that time, you--could you please further explain what--the answer to that question?

18 DR. GERDES:

Certainly. The correct procedure actually would be, the minute you see any indication of contamination, you need to shut down your operation, you need to clean up with bleach, you need to make new reagent, you need to identify the source of contamination, do a large number of negative controls to make sure they're clean and that you've gotten away from whatever the problem is, and only then do you repeat the test and go on.

KEY QUOTE
19 MR. SCHECK:

Now, should those steps, in terms of documenting the contamination and the efforts to correct it, be documented?

20 DR. GERDES:

Yes.

21 MR. SCHECK:

Were those documented in the data you saw from the Los Angeles Police Department?

22 DR. GERDES:

No.

23 MR. SCHECK:

Just where--what is the significance in terms of contamination that these are proficiency test samples that come from an outside source and you see this contamination?

24 DR. GERDES:

It simply means that the laboratory has introduced this contaminant into the specimen.

25 MR. SCHECK:

And the contamination here caused in your judgment an incorrect typing?

26 DR. GERDES:

That's correct.

27 MR. CLARKE:

Objection. Leading. Also calls for speculation.

28 THE COURT:

Sustained. The answer is stricken. Rephrase the question.

29 MR. SCHECK:

Can we have the next slide, please, which would be 1314-C.

30 MR. SCHECK:

Is this the--

31 DR. GERDES:

This is the rerun on 7-15-93 of that same proficiency test. And again, no. 1, female reference sample was once again typed as 1.3, 4, indicating that they did nothing to remove the contaminant. It's still there. It's still causing the same error. The correct type should have been a 1.2, 4, and on this particular occasion, the negative control was once again showing DNA and the DNA that was shown is a 1.2, 1.3 this time.

32 MR. SCHECK:

Next slide, please. 1314-D I believe.

33 DR. GERDES:

So again, there is an incorrect type on the sample itself.

34 MR. SCHECK:

Next slide, please.

35 DR. GERDES:

The contaminating alleles of this particular run were a 1.2 and a 4.

36 MR. SCHECK:

Next--

37 MR. SCHECK:

On 7-14, the contaminating alleles were?

38 DR. GERDES:

A 1.2 and a 4.

39 MR. SCHECK:

All right. And let's--next slide.

40 DR. GERDES:

And the contaminating runs on 7-15 were 1.2 and 1.3.

41 MR. SCHECK:

Next slide.

42 DR. GERDES:

So between those two days, you can see how random this process is. What we have is a 1.3 has now appeared on the negative control strip and the 4 contaminant has disappeared.

43 MR. SCHECK:

Is this any way to run a railroad?

KEY QUOTE
44 MR. CLARKE:

Excuse me. Objection. Argumentative.

45 MR. SCHECK:

Excuse me. Is this any way to run a DNA laboratory?

46 MR. CLARKE:

Same objection, your Honor. Also--

47 THE COURT:

Overruled.

48 DR. GERDES:

No.

49 MR. CLARKE:

It's also beyond the scope of the witness' expertise.

50 THE COURT:

Overruled.

51 MR. SCHECK:

Just briefly, Mr. Clarke asked you about other PCR base techniques. For example, he asked you about laboratories that can detect a single cell. Do you recall those questions?

52 DR. GERDES:

I do.

53 MR. SCHECK:

When laboratories are amplifying up and doing a PCR base technique on a single cell, how many negative controls do they ordinarily use for that application?

54 MR. CLARKE:

Objection. No foundation.

55 THE COURT:

Overruled.

56 DR. GERDES:

They would use generally 10 for each sample.

57 MR. SCHECK:

And why is that?

58 DR. GERDES:

When you're looking at something of that low a concentration, you need to be absolutely sure that you are not getting contamination.

59 MR. SCHECK:

And would it be a fair statement that depending on the application, different controls are necessary?

60 DR. GERDES:

Yes.

61 MR. SCHECK:

Now, you were asked a whole series of questions about not having done forensic samples in your own laboratory and not attending forensic meetings. Do you recall that?

62 DR. GERDES:

I remember those.

63 MR. SCHECK:

And incidentally, you were asked some questions about attending forensic meetings at the FBI. Do you recall those?

64 DR. GERDES:

I remember.

65 MR. SCHECK:

And can anybody go to those FBI meetings?

66 DR. GERDES:

No. You need to be invited.

67 MR. SCHECK:

Did they ever invited you?

68 DR. GERDES:

No.

69 MR. SCHECK:

Now, you can go to other forensic meetings voluntarily; is that correct?

70 DR. GERDES:

Yes, you can.

71 MR. SCHECK:

Now, you have criticized here, have you not, the method that the Los Angeles Police Department personnel used in collecting the blood swatches wet in plastic bags. You recall that?

72 DR. GERDES:

I do.

73 MR. SCHECK:

To evaluate the scientific merits of that procedure, do you believe that you're unable to do so because you have not attended forensic meetings?

74 DR. GERDES:

No.

75 MR. SCHECK:

That you haven't done specifically forensic samples in your laboratory?

76 DR. GERDES:

No.

77 MR. SCHECK:

Upon--is your--what is your opinion based upon?

78 DR. GERDES:

I think the fundamental science here is basically microbiology because that's the science that deals with how to manipulate and handle samples in such a way to prevent cross-contamination and to prevent them from becoming degraded.

79 MR. SCHECK:

And your experience as a DNA laboratory director, does that have relevance here too?

80 DR. GERDES:

Yes.

81 MR. SCHECK:

In terms of the procedures followed on June 13th in taking the swatches out of the plastic bags from Bundy and Rockingham, not changing gloves, not changing papers when put into test tubes, do your criticisms of that depend upon, in your judgment, attendance of forensic meetings or doing forensic samples?

82 DR. GERDES:

No.

83 MR. SCHECK:

What about the methods used for taking those samples out of the test tubes by scraping and creating aerosols? Does your criticisms of that depend upon the attendance of forensic meetings or running forensic samples?

84 DR. GERDES:

No.

85 MR. SCHECK:

What is--what are those criticisms based on?

86 DR. GERDES:

Once again, the fundamental issue here is understanding how those manipulations can cause cross-contamination. That's a microbiology issue.

87 MR. SCHECK:

Is it an issue also as a DN--in terms of--

88 DR. GERDES:

In a DNA or molecular biology PCR lab. Those are molecular biology fundamental science issues.

89 MR. SCHECK:

In terms of handling Mr. Simpson's reference sample in the way that Mr. Yamauchi did along with the Rockingham glove and all the Bundy blood drop swatches between 9:00 and 11:00 o'clock on the morning of June 14th, in terms of your criticisms with that, do you believe that it is necessary to attend forensic meetings?

90 DR. GERDES:

No.

91 MR. CLARKE:

Objection. Calls for speculation.

92 THE COURT:

Overruled.

93 MR. SCHECK:

Do you believe that not having done forensic samples in your laboratory makes you unable to evaluate that?

94 DR. GERDES:

No.

95 MR. SCHECK:

What are your criticisms based on in terms of your background and experience?

96 DR. GERDES:

Once again, it's a fundamental question of basic training in microbiology and molecular biology as to how to handle these items that contain very small amounts of material in such a way so that you don't have the risk of creating error and cross-contamination.

97 MR. SCHECK:

Mr. Clarke asked you about the fact that you once testified for a Prosecutor and on other times testified for Defense lawyers. Do you recall that?

98 DR. GERDES:

Yes.

99 MR. CLARKE:

Objection. Misstates the evidence.

100 THE COURT:

Overruled.

101 MR. SCHECK:

Does it--in terms of--do you--does it matter to you which side you testify for?

102 DR. GERDES:

No.

103 MR. SCHECK:

Upon what do you make your decisions as to--in terms of your testimony?

104 DR. GERDES:

I'm asked to evaluate the science as to whether the science is fundamentally sound and that's what I express an opinion about.

KEY QUOTE
105 MR. SCHECK:

And you testify for either side?

106 DR. GERDES:

Correct.

107 MR. SCHECK:

Now, you were asked some questions about the money that you've been paid in this case and your salary. Do you recall those?

108 DR. GERDES:

Yes.

109 MR. SCHECK:

And do you recall the questions that you're being paid at what, the rate of $100 an hour here?

110 DR. GERDES:

That's correct.

111 MR. SCHECK:

And that your salary at IAD is not at $100 an hour. Do you recall those questions?

112 DR. GERDES:

Yes.

113 MR. SCHECK:

Now, first of all, do you personally receive the money that you get from this case or any others where you testify as a witness?

114 DR. GERDES:

No. All of the lab--all of the charges go directly to my laboratory.

KEY QUOTE
115 MR. SCHECK:

And in terms of the amount of money that--you write grant proposals; is that correct?

116 DR. GERDES:

Yes.

117 MR. SCHECK:

And as part of that, do you have to make an assessment of how much it costs IAD to have you as an employee?

118 DR. GERDES:

Yes. That's part of writing a budget for a grant.

119 MR. SCHECK:

And is the expenditure of money that IAD pays you reflected merely in your salary?

120 DR. GERDES:

No. You have an additional 43 percent in indirects and benefits.

121 MR. SCHECK:

All right. And when you're away from the laboratory, does IAD's--is there an opportunity cost for IAD? Could you explain what that term is?

122 DR. GERDES:

Yes. Well, since I'm not at the laboratory, my function at the laboratory is to promote the work of that laboratory. So my productivity is lost. It's just not my time, but my productivity in terms of working in the lab and getting business for that laboratory is lost to the company.

123 MR. SCHECK:

Now--

124 MR. SCHECK:

This is the last line of questions, your Honor.

125 MR. SCHECK:

Dr. Gerdes, you indicated that over a five-year period, you have testified in court about 23 times?

126 DR. GERDES:

That's correct.

127 MR. SCHECK:

All right. And in those cases, your CV has been put into evidence?

128 DR. GERDES:

Yes.

129 MR. SCHECK:

And you've been questioned extensively about your background?

130 DR. GERDES:

Yes.

131 MR. SCHECK:

And you indicated I think at the very beginning of the cross-examination that there came a period of time--let's see. You indicated you got your Ph.D. in four years at UCLA?

132 DR. GERDES:

Correct.

133 MR. SCHECK:

Then you did post-graduate work for three years?

134 DR. GERDES:

Correct.

135 MR. SCHECK:

Also at UCLA?

136 DR. GERDES:

Correct.

137 MR. SCHECK:

Then you moved to Hawaii?

138 DR. GERDES:

No. Then I went to Denver for--

139 MR. SCHECK:

Denver. I'm sorry.

140 DR. GERDES:

As an assistant professor for four years first.

141 MR. SCHECK:

And then you moved to Hawaii?

142 DR. GERDES:

Then I moved to Hawaii.

143 MR. SCHECK:

All right. And you were asked about that, right?

144 DR. GERDES:

Yes.

145 MR. SCHECK:

Why did you move to Hawaii and sort of get off this track?

146 DR. GERDES:

Well, it was a personal decision. I had a small son, and I decided to play Mr. Mom for a few years, and so we went to Hawaii.

147 MR. SCHECK:

Your wife had an opportunity there?

148 DR. GERDES:

She had an opportunity for a job.

149 MR. SCHECK:

And you indicated--why did you--could you explain a little bit about why you had to be on television when you taught these classes at the community college?

150 DR. GERDES:

Well, in Hawaii, there are a series of islands, and it's just the best way to communicate to remote sites.

151 MR. SCHECK:

And, finally, Dr. Gerdes, you were asked about working for the pineapple factory. Do you recall that?

152 DR. GERDES:

Yes.

153 MR. SCHECK:

All right. Does that have some relevance to the issue of contamination?

154 DR. GERDES:

In fact it does.

155 MR. SCHECK:

Could you please tell this jury what you did for the pineapple company?

156 DR. GERDES:

Well, the pineapple company had a problem with their cans blowing up. In fact, they had--

157 MR. SCHECK:

What do you mean by blowing up?

158 DR. GERDES:

Well, they would swell up and then just explode, and basically they had some of the workers injured in fact from this. So I was called in to track down why those cans were blowing up, and it turned out to be bacterial contamination.

159 MR. SCHECK:

Thank you very much, doctor.

Temperature

procedural

Key Quotes (5)

Dr. John Gerdes
28 percent of the times.
Gerdes stated that in 28% of cases he examined, contamination occurred that was not detected by the negative control — the quality check meant to catch exactly this problem.
Dr. John Gerdes
The correct procedure actually would be, the minute you see any indication of contamination, you need to shut down your operation, you need to clean up with bleach, you need to make new reagent, you need to identify the source of contamination, do a large number of negative controls to make sure they're clean and that you've gotten away from whatever the problem is, and only then do you repeat the test and go on.
Gerdes described the proper protocol that LAPD failed to follow when contamination was detected, and confirmed these corrective steps were never documented.
Barry Scheck
Is this any way to run a railroad?
A memorable (and objected-to) rhetorical flourish that Scheck quickly rephrased; captures the defense's overall contempt for LAPD lab procedures.
Dr. John Gerdes
I'm asked to evaluate the science as to whether the science is fundamentally sound and that's what I express an opinion about.
Gerdes rebutted the implication of bias, asserting his opinions are science-driven regardless of which side retained him.
Dr. John Gerdes
No. All of the lab--all of the charges go directly to my laboratory.
Directly neutralized Clarke's financial bias attack by clarifying Gerdes personally receives none of the expert witness fees.

Evidence (1)

Defense 1314-A through 1314-G
Slides showing LAPD proficiency test results from July 14-15, 1993, documenting contamination in negative controls and incorrect DNA typing
introduced and discussed in detail

Notable Exchanges (2)

Barry ScheckGeorge ClarkeLance A. Ito
Scheck asked 'Is this any way to run a railroad?' — Clarke objected as argumentative — Scheck immediately rephrased to 'Is this any way to run a DNA laboratory?' — Clarke renewed the objection and added a scope objection — Ito overruled both.
theatrical, strategic
Barry ScheckDr. John Gerdes
Scheck methodically walked Gerdes through each of his qualifications and criticisms of LAPD lab procedure, asking whether each critique depended on forensic meeting attendance or forensic lab experience; Gerdes answered 'No' each time, grounding his opinions in fundamental microbiology.
strategic rehabilitation

Light Moments (3)

Dr. John Gerdes
Gerdes explained his career detour to Hawaii by saying 'I had a small son, and I decided to play Mr. Mom for a few years, and so we went to Hawaii.'
Dr. John Gerdes
Gerdes described his work for a pineapple company investigating why cans were 'blowing up' and injuring workers — revealed as a contamination case analogous to the trial's DNA issues.
Barry Scheck
Scheck asked 'Is this any way to run a railroad?' before catching himself and rephrasing for the court record.

Credibility Attacks (2)

⚔ Dr. John Gerdes
rehabilitation after bias attack
Scheck rebutted Clarke's implication that Gerdes was financially motivated by eliciting that all fees go to his laboratory, not to him personally, and that he testifies for prosecution and defense alike.
⚔ Dr. John Gerdes
rehabilitation after expertise attack
Scheck systematically countered Clarke's cross-examination attacks on Gerdes's lack of forensic lab experience and non-attendance at FBI meetings, establishing that Gerdes's opinions rest on fundamental microbiology and molecular biology rather than forensic-specific credentials.

Objections

7 objections (1 sustained, 5 overruled)
Proceeding 7216 • 159 utterances • Defense witness
Criminal Trial
Department 103
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📂 AUG 7, 1995 📄 Redirect examination of Dr. Jo
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