Dan Small: Expert witnesses pose a wide range of challenges. Let's answer just a few questions about them.
Question one: If your opponent offers to stipulate to your expert's qualifications, should you agree and move on?
Answer: generally no.
If your expert has great qualifications, let the jury hear them, even if only in summary. A cold printed resumé may look impressive, but it may not mean much to a jury and certainly won't have as much impact as testimony about everything that went into it.
For example: Have you won any prizes or rewards?
Answer: Yes.
Can you give us an example?
Well, I won the Nobel Prize for medicine.
The resume stops there. But you want more?
What did you do to win that prize?
Well, according to the Nobel Prize Committee, it was for my research on certain types of cancer. They believe that it's life-saving for many patients.
Qualifications testimony gives the jury a chance to get to know the witness and understand why their qualifications matter. And why their testimony is worth listening to.
Number two: Should you prepare your expert witness for testimony?
Answer: Absolutely yes. Extensively.
Lawyers too often fail to prepare their witnesses adequately because they fall into one of two common traps. Trap number one: Well, my expert has testified many times before. He doesn't need my help. Or trap number two: My expert knows more about the subject than I do, so I don't need to prepare her. As to the first, you are trial counsel. It's your case. If your expert has testified before, does that mean that he or she is a great witness who needs no instruction, or that they've developed bad habits over the years, and you need to break those habits? Find out. As to the second, it's your responsibility to make sure you understand what your expert has to say and help her find the best ways to communicate to the jury. You're in charge, not the expert.
In my recent ABA book, Lessons Learned from a Life on Trial, I talk about a case I prosecuted involving an export grain elevator that exploded, killing 18 people. The defense put up an expert who gave a nice, short, polished presentation on direct. Very good. But on cross, it became apparent that defense counsel had not prepared and practiced enough. When I started asking substantive questions, the witness could just repeat parts of his short presentation until it became clear that it was a sham. His expertise was only as deep as that short, well-prepared presentation. There was nothing of value behind the curtain.
Number three: Should you pose your opinion questions to the expert in the form of hypothetical questions?
Generally, no, unless the law of the jurisdiction requires it.
Hypothetical questions to experts are often tangled, and often incomprehensible. They're also fraught with opportunities for mistakes and for being turned around by the other side. Keep it as clear, simple and direct as possible.
Number four: Should your expert use visual aids?
Absolutely, yes.
Expert testimony is often complicated, but it's almost always important. Visual aids can help jurors focus and understand the testimony. They also may give the expert a chance to get the heck off the witness stand and really present to the jury and hopefully really connect with the jury.
Number five: Should your expert express their disagreement with the opposing expert's opinion?
Answer: Yes, if the rules of court permit it
It's much easier to understand the differences between experts if they can freely talk about their disagreements. An expert cannot opine on the credibility of another witness or another expert or normally criticize another expert's qualifications. But, for example, whether the opposing expert used the correct methodology, or interpreted the data correctly, all that ought to be fair game. You can say that the other side's expert is wrong in your closing, but your expert can say it more professionally and more credibly.
