You don’t want jurors thinking your expert is a “hired gun” or otherwise nurturing thoughts to decrease the effectiveness of expert’s testimony. Yet, it commonly happens. An old literature review (Devine et al., 2001) and a newer research study (Boudreau and McCubbins, 2009) shed light on best practices to avoid juror dismissal of your expert’s testimony.

Devine et al. (2001) describe the 1997 Capital Jury Project’s findings on juror reactions to three kinds of witnesses: professional experts, lay experts and families and friends of the defendant.

Perhaps not surprisingly, professional experts were most likely to be seen negatively, as often damaging the case for their side, and as having little credibility.

Those experts that were seen positively did two specific things: 1) they integrated their testimony with the specific facts of the case and 2) they explained how their general points applied to the case at hand.   In other words, they stopped being expert witnesses, and became expert teachers.  The jurors stopped focusing on whether they were a hired gun, and started focusing on what was being provided to them for their use in solving a problem.

Devine et al. (2001) conclude that expert witness testimony should have “novel and useful” information for the jury and should be tailored to the specific case being tried. They caution that jurors do not simply accept the testimony of expert witnesses as factual—but rather that jurors tend to scrutinize experts and even view them somewhat cynically.

Boudreau and McCubbins (2009) address the thorny issue of competing expert testimony. What they find is that competing/conflicting expert testimony is very difficult for “unsophisticated subjects” (aka jurors) to sort through and then make accurate decisions. And the more difficult the facts, the worse decisions are made. (This is not generally good.) But when experts are told to testify with the threat of fact verification and the competing experts exchange ideas as to why their interpretation should be seen as accurate, “unsophisticated subjects” do just as well at sorting through the testimony as “sophisticated subjects”.

We often hear mock jurors complaining about dueling experts. They don’t like it. They don’t like feeling ‘talked down to’ and ‘not very bright’ because they can’t ascertain the truth between opposing experts in fields in which the jurors have little to no expertise/education/experience. Devine et al. shares the descriptive reality for jurors while Boudreau and McCubbins tell us what to do about it.

• Structure your expert’s testimony around the facts of the case. Have the expert explain their testimony in relation to the case facts.

• On cross-examination, ask them to explain how their explanation is more correct than the other side’s expert testimony.

• Make sure your expert’s testimony is factually accurate and examine the opposing witness’ testimony for factual accuracy. Showing jurors how a portion of an expert’s testimony is self-serving will kick in their tendency to doubt the expert’s credibility in total.

And as ridiculous as it might sound, during preparation emphasize to the witness the need to be nice.  Expert witnesses are the worst when it comes to arrogance and gamesmanship.  Getting them to be friendly, useful, and charmingly geeky is often quite a challenge.

Boudreau, C. and McCubbins, M. (2009). Competition in the Courtroom: When does expert testimony improve jurors’ decisions? Download from SSRN.

Devine, D., Clayton, L., Dunford, B., Seying, R. and Pryce, J. (2001). Jury Decision Making: 45 years of empirical research on deliberating groups. Psychology, Public Policy and Law, 7(3), 622-727.

Related posts:

1. Simple Jury Persuasion: The Alpha Strategies
2. Simple Jury Persuasion: She reminds me of my Grandmother…
3. Simple Jury Persuasion: Beware what the other side will tell you…
4. Simple Jury Persuasion: The ‘attitude alignment’ effect & persuasion
5. Simple Jury Persuasion: When it comes to litigation persuasion–hard sell, soft sell, or no sell?

1. Doug Keene says:

   March 12, 2010 at 10:49 AM

   Tim, Thanks for your comment. As I re-read the blog post I wish I had written it more artfully, so we might be discussing a different nuance. My point is that willingness to respectfully disagree and express mastery over the opposition expert material is crucial. You are right, that your expert isn’t likely to achieve that during cross, but more likely in your direct or re-direct. They can either do that by commenting on prior testimony or by commenting on expert reports. But I agree with you completely; experts who try to score while on defense (during cross) usually look argumentative, elicit non-responsiveness objections, are viewed as improper advocates, and are not liked as much.
2. Timothy R. Hughes says:

   March 12, 2010 at 7:57 AM

   It is not ridiculous at all on the be nice comment – likeability is critical.

   Great post, although I do have a question about this:
   “On cross-examination, ask them to explain how their explanation is more correct than the other side’s expert testimony.”

   I assume this is you coaching your expert on how to deal with the other side’s cross? Good advice, but a good lawyer on the other side will make this difficult or impossible. I tend to ask very tight, very leading questions on cross and not permit much wiggle to avoid having the opposing expert try to turn the tables on me.