A BU cancer epidemiologist talks about being an expert witness in court cases, why he gets involved in lawsuits, and his recent battle with IBM.

Corie Lok

Richard Clapp has been in and out of court for the last 17 years…as an expert witness, that is. The cancer epidemiologist and Boston University environmental health professor has testified on average once a year during this period, typically in lawsuits where community residents or factory workers were trying to prove that their exposure to a chemical gave them an illness, like cancer.

Because of Clapp’s research on the health effects of dioxin and other toxins and his work directing the Massachusetts Cancer Registry during the 1980s, he’s been regularly called on by lawyers—most often the ones representing workers or residents—to give his opinion on the relevant scientific literature.

Through his involvement, Clapp has become familiar with the way science can play out in the courtroom. He’s also experienced the difficulties. Earlier this month, after a two-year legal battle, he succeeded in publishing a paper showing higher cancer death rates among IBM workers.

This paper was controversial because to do this analysis, Clapp used employee data collected by IBM made available to him through a lawsuit filed by two former IBM employees. They argued that working in IBM factories harmed their health and commissioned Clapp to analyze the data and be an expert witness in the case.

After the judge prevented Clapp’s analysis from being presented as evidence to the jury, and the plaintiffs lost their case, Clapp wanted to publish his work. He said that the data were now part of the public court record as a result of the lawsuit, but IBM argued that the data were still confidential.

Earlier this spring, a judge ruled that the data were public, allowing Clapp to publish. He will present his paper next week at the meeting of the American Public Health Association at the Boston Convention Center.

Clapp sat down with Nature Network Boston to talk about whether science can be presented and used fairly in court.

What did you do as an expert witness?

The work involves a general review of the literature and giving an opinion of whether the exposure causes the disease that is at issue in the trial. It’s called a general causation opinion.

Juries, lawyers, and judges are looking for simple, straight answers, but in science, there often aren’t simple, straight answers. How difficult is it to be an expert witness in court, where most people aren’t scientists?

It requires a different style of presentation. The science is the same, but it’s really in how you summarize it and how you say what you think it means. In science, the usual thing is to be very skeptical, to point out weaknesses in studies.

But the court doesn’t want to hear that and juries get confused by it. So they want you to boil it down and explain what it all means. That’s the main difference: that final interpretation that you tend to give in court of what it all means.

Do you ever feel uncomfortable giving that bottom-line conclusion?

Not anymore. When I first got into this, I thought, the lawyers are just going to want me to say what they want. But I don’t do that. I say what I believe. If it helps the attorneys for the plaintiffs, so be it.

And what if it doesn’t?

Then usually, the lawyers don’t come to me, or they don’t put me in front of a jury. I’m not in a position of having to change what I would say in order to be a witness.

Why do you agree to testify? It must be a lot of extra work.

It is a lot of extra work. I don’t get paid extra for it. But someone has to level the playing field. It seems like defendants are almost always able to get chairs of departments and other scientists to work for them. Plaintiffs have a much harder time. I feel like in order to level the playing field, I need to get involved.

How have you seen science used and interpreted in the courtroom?

I find that the defense attorneys spend most of their time trying to whittle away at the basis for my opinion in depositions and in a trial. They try to undermine or somehow diminish your credibility. It’s almost always nitpicking, things that have nothing to do with your opinion. I suspect that experts for the defendants feel the same about how they’re treated by plaintiffs’ lawyers.

It’s suspicious when the science is used or undermined in that way. But that is what the adversarial system is like.

And how have judges and juries dealt with the science, in your experience?

Federal judges are bound by the Supreme Court Daubert decision [the 1993 U.S. Supreme Court decision in Daubert v. Merrell Dow Pharmaceuticals] to use specific rules to decide whether to allow scientific testimony in court. I’m part of the Scientific Knowledge and Public Policy project. We call it SKAPP. It’s about revisiting this Daubert decision about how judges are being asked to interpret the scientific literature. We think it’s wrong.

In my experience though, some judges are quite good and knowledgeable. But they may not have much science background. The ones who don’t, if they’re wise, let the cross-examination process sort it out and based on that, the jury makes its decision.

As for juries, I’m a big believer of the jury system. In the end, it works. Juries vary and the skill of the attorneys in eliciting your opinion varies. But in my experience, most of the time, I felt that what I was trying to say did get across to the jury.

Do you feel that justice was served in the cases you were involved with, that the decisions made were in line with the scientific evidence at the time?

In my experience, yes. Now that’s not to say that the plaintiffs always won, though.

Do you often run into trouble like you did in the IBM case?

No, that was the first time.

What was that two-year battle like?

There was a lot of back and forth, writing and responding to affidavits. But it worked.

How do you maintain scientific objectivity in a system that’s so inherently adversarial?

I don’t find it difficult at all. I give my opinion and I don’t have to color it one way or the other. I don’t succumb to any pressure to do that.

I actually think it’s a responsibility of scientists to give their opinion in court and to do it honestly. If your opinion is different from what someone else believes, that’s fine. That’ll come out in cross-examination. Which opinion is more valid, let the jury decide that. That’s the way it’s supposed to work and I think it does work.

Do you feel that your credibility as a scientist is hurt in any way by the fact that you’ve testified mainly for the plaintiffs’ side? You’ve been called an “advocate” before, haven’t you?

I don’t think my credibility as a scientist has been hurt by the fact that I testify mainly for the plaintiffs’ side. My publications still get accepted in peer-reviewed scientific journals, and I get asked to consult by government agencies and speak at other universities. I am an advocate for public health and I try to teach my students to be advocates for public health, as well.