Prime Time Replay:


David A. Kalman, Ph.D.
on the use of expert witnesses in the courtroom



MsgId: *breakthrough(1)
Date: Wed Apr 23 20:40:03 PDT 1997
From: moderator At: 206.80.182.179

Hello, and welcome to Breakthrough Medicine. I'm Madeleine Lebwohl, and tonight I'll be speaking with David Kalman, Ph.D, on the skills and issues that help professionals testify as expert witnesses in court. Dr. Kalman is a chemist who has been actively involved pesticide exposures, exposures to arsenic, exposures to organic solvents, ambient air quality and urban combustion sources, landfills and solid waste management, and interindividual variation in exposure/biomarker relationships.

Dr. Kalman is in the Department of Environmental Health, School of Public Health and Community Medicine, at the University of Washington, Seattle.

MsgId: *breakthrough(3)
Date: Wed Apr 23 20:53:36 PDT 1997
From: Dave_Kalman At: 128.95.23.29

Good evening, Madeleine. I'm now with you.
MsgId: *breakthrough(4)
Date: Wed Apr 23 20:57:30 PDT 1997
From: moderator At: 206.80.182.179

Nice to have you here. Let's start by talking about some of the basic ground rules that scientists have to remember when they're asked to be expert witnesses for a trial.
MsgId: *breakthrough(5)
Date: Wed Apr 23 20:58:47 PDT 1997
From: Dave_Kalman At: 128.95.23.29

The first thing I'd tell a colleague who had no experience with expert testimony is that the process and rules are different from what he/she is used to. Therefore, it is important to learn what's going on ahead of time.
MsgId: *breakthrough(6)
Date: Wed Apr 23 20:59:55 PDT 1997
From: moderator At: 206.80.182.179

How is the legal process different from the scientific process?
MsgId: *breakthrough(7)
Date: Wed Apr 23 21:01:11 PDT 1997
From: Dave_Kalman At: 128.95.23.29

First, the legal process is adversarial and scientists are used to consensual or collegial fact-finding. In a court proceeding, two highly biased advocates are trying to sway a hopefully neutral party (the jury or judge).
MsgId: *breakthrough(8)
Date: Wed Apr 23 21:01:58 PDT 1997
From: moderator At: 206.80.182.179

So how does the scientist proceed?
MsgId: *breakthrough(9)
Date: Wed Apr 23 21:04:00 PDT 1997
From: Dave_Kalman At: 128.95.23.29

A second important difference, before I answer your last question, is that the standard of certainty to reach a conclusion is much lower, especially in civil litigation. Scientists don't like to consider an opinion valid unless the level of confidence in very high, greater than 95% in most cases. In a lawsuit, 51% or "more probable than not" is the standard for reaching a finding.
MsgId: *breakthrough(10)
Date: Wed Apr 23 21:06:05 PDT 1997
From: moderator At: 206.80.182.179

Well, that's certainly a different standard. Not the level of proof generally accepted in science. How do you account for this difference?
MsgId: *breakthrough(11)
Date: Wed Apr 23 21:06:37 PDT 1997
From: Dave_Kalman At: 128.95.23.29

One reason for the difference is that science can afford to label a problem as unresolved or awaiting further study. Legal proceedings HAVE to reach a resolution whenever possible, or nothing would ever be settled. So the law forces us to get off of the fence.
MsgId: *breakthrough(12)
Date: Wed Apr 23 21:08:12 PDT 1997
From: moderator At: 206.80.182.179

Is this where how your lawyer interprets what the expert witness is saying becomes a crucial part of how the trial goes?
MsgId: *breakthrough(14)
Date: Wed Apr 23 21:10:06 PDT 1997
From: Dave_Kalman At: 128.95.23.29

Right. The lawyer can interpret the expert in closing argument, but before that, the lawyer will want to package the expert's views in a way that makes his case most strongly. So the lawyer will want the expert to phrase things in a certain way, and avoid other statements.
MsgId: *breakthrough(15)
Date: Wed Apr 23 21:12:29 PDT 1997
From: moderator At: 206.80.182.179

It seems that a scientist is faced with giving testimony that can be interpreted in different ways. How can you protect what you're saying from interpretations that you would really dislike?
MsgId: *breakthrough(16)
Date: Wed Apr 23 21:14:50 PDT 1997
From: Dave_Kalman At: 128.95.23.29

This is a key challenge for scientists in courtroom settings. The goals of the lawyer are to win the case. The goals of the scientist are to: 1. not be humiliated and 2. not to have his/her views distorted. There are lots of techniques to use, but the first one is to be choosy whom you work for and resist manipulation.

One point is to find out about a case and the attornety before agreeing to serve as an expert. A second point is to clearly communicate the limits of your expertise. A third point is to form your opinions carefully and stick to them except as you have scientific reasons to change your mind.

MsgId: *breakthrough(18)
Date: Wed Apr 23 21:19:01 PDT 1997
From: moderator At: 206.80.182.179

In your own experience, how have you been treated in the courtroom? Did you feel your testimony was used effectively?
MsgId: *breakthrough(19)
Date: Wed Apr 23 21:20:46 PDT 1997
From: Dave_Kalman At: 128.95.23.29

I've actually been fairly pleased with my experiences. The highly dramatic upset of an expert becuase of impeachment or surprise on cross examination is not all that common, although it happens. It's hard for an expert to know what role his/her testimony played ina verdict, but you do get a sense of whether the jury (or judge in some situations) followed you and believed you.

I should add that I don't do this every month or even every year. I've given trial terstimnony a few times, in state and federal court. I've given written testimony by deposition or affidavit more often.

MsgId: *breakthrough(21)
Date: Wed Apr 23 21:22:57 PDT 1997
From: moderator At: 206.80.182.179

What was your day in court like?
MsgId: *breakthrough(22)
Date: Wed Apr 23 21:24:06 PDT 1997
From: Dave_Kalman At: 128.95.23.29

You spend a lot of time waiting to be called, because the timing of completion of the previous witnesses is uncertain, and you need to be on hand. In many proceedings, testifiers are excluded, so you sit in a waiting room tapping your toes.

Once you get called and sworn, you usually spend 15 minutes to hours going over your pedigree (education, publications, etc) to establish that you're an expert. Then the attorney you work for will ask you questions to give you an opportunity to state your expert opinions, followed by cross examination by the opposing attorney.

MsgId: *breakthrough(24)
Date: Wed Apr 23 21:26:55 PDT 1997
From: moderator At: 206.80.182.179

What was the last subject you testified about?
MsgId: *breakthrough(25)
Date: Wed Apr 23 21:28:53 PDT 1997
From: Dave_Kalman At: 128.95.23.29

The last time I gave courtroom testimony was in a case involving toxic chemicals at a landfill. This kind of case is known as a "toxics tort". In my case, a manufacturer had sold a byproduct of their operations as a harmless soil additive, and their clients then discovered that they had major liability for releases of toxic chemicals from this material. The amended soils were taken to a local landfill which subsequently became a Superfund site. The cleanup costs are running to the tens of millions of dollars, so there is a lot at stake in terms of liability.
MsgId: *breakthrough(27)
Date: Wed Apr 23 21:31:45 PDT 1997
From: moderator At: 206.80.182.179

Which side did you testify for?
MsgId: *breakthrough(28)
Date: Wed Apr 23 21:33:12 PDT 1997
From: Dave_Kalman At: 128.95.23.29

There were three groups of parties in the matter: the primary plaintiffs (the landfill owners and operators who were being held accountable by EPA), the companies who bought the byproduct and sent it to the landfill, and the company that originated the hazardous materials in the first place. I was retained by the middle group.
MsgId: *breakthrough(29)
Date: Wed Apr 23 21:34:40 PDT 1997
From: moderator At: 206.80.182.179

Are many experts called for cases like this?
MsgId: *breakthrough(30)
Date: Wed Apr 23 21:36:13 PDT 1997
From: Dave_Kalman At: 128.95.23.29

In cases like this one (especially considering the amount of money on the table) huge numbers of experts are involved: experts in the manufacturing processes, in site assessment, in remedation technology, in toxicity and risk to the public, in economic issues, etc. I testified as to the chemical behavior of the toxic components in the materials that were used.
MsgId: *breakthrough(31)
Date: Wed Apr 23 21:37:42 PDT 1997
From: moderator At: 206.80.182.179

Have you coordinated your testimony with other experts?
MsgId: *breakthrough(32)
Date: Wed Apr 23 21:39:56 PDT 1997
From: Dave_Kalman At: 128.95.23.29

In many cases, yes. One reason is that the main questions being decided at trial go beyond one expert's field. So one expert will rely on the opinion of another expert as a basis for her own evaluation. For example, a paint chemist might conclude that a certain chemical was probably in a given paint. An occupational health specialist might use that to estimate what exposures to that chemical could have taken place. A physician might rely on that to conclude that the paint caused an illness, etc.
MsgId: *breakthrough(33)
Date: Wed Apr 23 21:41:22 PDT 1997
From: moderator At: 206.80.182.179

Has anyone tried to shake your credibility? What do you do when that happens?
MsgId: *breakthrough(34)
Date: Wed Apr 23 21:43:17 PDT 1997
From: Dave_Kalman At: 128.95.23.29

I've had only a few occasions when I thought that I was being asked questions aimed at my credibility. There are a few ways this can be done. The most common is to get an expert to give contradictory opinions. This pretty well nullifies that the expert has to say. A less common but sometimes used approach is to show that the expert is biased - for example by having a financial tie to the side he represents or for other prejudicial reasons.

The best defense it to avoid putting yourself at risk. Don't give contradictory opinions, and be prepared to explain any apparent inconsistencies. Don't get into a conflict of interest situation. Don't wed yourself to a point of view or agenda that prevents you from reaching an impartial weighing of the facts in each case.

One key rule is to assume that anything you've said "on the record" -- in scientific papers, in other trials or depositions, or even in public meetings -- could be brought into your courtroom. If you go around calling the auto industry a bunch of irresponsible crooks, you'd be wise to not offer yourself as an unbiased expert in matters pertaining to them.

There was an example from a recent court case where an expert was asked under oath if he had referred to plaintiffs in a certain type of issue as "turkeys" and suggested that they were out to "screw the system". Needless to say, he was both embarrassed and nullified as an expert.

The folks who are most at risk for this kind of trap are frequent testifiers. I don't like to do a lot of legal testimony, partly so I don't have to keep remembering everything I've ever said on a subject.

MsgId: *breakthrough(39)
Date: Wed Apr 23 21:57:42 PDT 1997
From: moderator At: 206.80.164.8

Considering all that can go on, why do scientists agree to be expert witnesses? Is it the money?
MsgId: *breakthrough(40)
Date: Wed Apr 23 21:57:55 PDT 1997
From: Dave_Kalman At: 128.95.23.29

The most obvious reason is money. Experts who spend most of their time testifying can generate incomes in 6 figures without much trouble. Even occasional forrays into legal matters can be very remunerative. However I have several other reasons for doing this type of work, and I think that most of my colleagues do as well. Some of my other reasons are: (1) to support and explain my other professional work. If I've published papers or other scientific reports that are being cited in a matter, or (in the case of a physican) my professional activities are pertinent to a court proceeding, then I feel obligated to present and support my own non-legal work. (2) It is a public service to provide my expertise to help resolve a legal question in a manner that respects the scientific issues and truths that might apply. If no good scientists will take part, then court proceedings will be swayed by bad science and hidden agendas. (3) There are actual benefits to me as a scientist from taking part in some court cases. Presenting your own work under the glare of cross examination will cause you to think differently about how you reach conclusions and document your activities. ( A little of this goes a long way . . . . ) (4) I actually blush a little to admit this, but I kind of enjoy (a little of) it, in a perverse way. It's kind of a cross between being in a debating society and "Quincy".
MsgId: *breakthrough(45)
Date: Wed Apr 23 22:07:37 PDT 1997
From: moderator At: 206.80.164.8

So you enjoy the entering the legal arena?
MsgId: *breakthrough(46)
Date: Wed Apr 23 22:08:57 PDT 1997
From: Dave_Kalman At: 128.95.23.29

It's an interesting place to visit, but I wouldn't want to live there. I am more of a tourist in the legal world. And my takehome message is " its best to be an informed tourist" as a testifying expert.
MsgId: *breakthrough(47)
Date: Wed Apr 23 22:10:14 PDT 1997
From: moderator At: 206.80.164.8

Dr. Kalman, thank you for taking us through the skills the experts use. Great to have had you here!
MsgId: *breakthrough(48)
Date: Wed Apr 23 22:10:33 PDT 1997
From: Dave_Kalman At: 128.95.23.29

Thank you -- this was fun. Good night!


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