In many cases the expert is the linchpin, the cleanup hitter.  And jurors really do want to trust and rely on them to guide their decisions.

So if opposing experts are giving conflicting information, your case may hinge on whoever jurors feel came out ahead on credibility and performance.  When it’s their expert vs. your expert, not just any expert will do; yours needs to be approachable, clear, and persuasive.

Your mediocre expert can lose to their convincing one. Or, as we’ve seen frequently with jurors, two experts of equal appeal just cancel each other out; and unfortunately, the defense case is usually at a disadvantage in that situation.

Finally, of course, a bad expert can actively damage your case.  We’ve worked with witnesses who are proud of being hostile during cross.  We’ve worked with a revered orthopedic surgeon who was so condescending and sarcastic he made even basic prep a nightmare.  Let’s just say that jurors don’t like these qualities.

How to Weed Out Bad Witnesses

If you’ve already hired a less-than-ideal expert, don’t worry; problem witnesses can still be salvaged (and even great experts can improve) through witness prep.  As always, though, the best way to ensure a good product is to start with the right raw materials. Moving forward, you’ll want to weed out bad experts first thing.

That means expanding your interview process:

Your Expert Interview Guideline

1.  Initial Interview.  This includes the standard questions. Gauge how well your experts know their field and how much relevant experience they have, and try to pick up on initial body language and demeanor cues.

2.  Check References – Thoroughly.  Beyond backing up what your experts told you in their initial interview, you’ll need to get a sense of how they’ll be as actual witnesses and as people you’ll be working with closely.  We recommend contacting the trial teams from their last few cases.  Be sure to ask references the following kinds of questions:

  • How easy were they to work with?
  • Did they do the preparation work themselves, or tend to hand it off to associates?
  • Were they responsive to feedback?
  • Could they learn quickly and remember the details and talking points?
  • What was their demeanor like on the stand? Did they come across as arrogant, condescending, rude, nervous, slick? Approachable, knowledgeable?
  • Were they a teacher to the jury? Were they able to explain complex ideas in ways a jury could understand, or did they fall back on technical jargon?  Did they incorporate case themes and advice into their testimony? Were they successful in creating, or directing a graphics designer to develop, pedagogical demonstratives that helped the jury understand these complex concepts?
  • Important:  Are there any deposition videos (or at least transcripts) available so we can see their performance and/or how they answer questions?

3.  Practical Interview.

If steps #1 and #2 go well, you’re on the right track.  But with something this significant, we highly recommend inviting your experts back to test them in action:  How will they handle being your actual witness?  Not enough teams incorporate real Q&A practice into their interviews because they don’t want to offend the expert.  Believe me, it is a lot more difficult to explain to your client why you have to fire an expert when a lot of money has been spent on him than it is to regain the expert’s trust, if he was indeed offended.

Here are a few ideas for eliciting sample testimony:

  • Give your experts a document and have them try to come up with some rough testimony.
  • Explain to them a major case theme or two and see if they can smoothly and convincingly work it into their response.
  • Present them with a complex idea or process and see how well they translate it into layman’s terms.

Now, some witnesses balk at this idea.  And guess what? That tells you something. If your expert turns her nose up at the thought of a test run, then her pride has announced itself to be more important than your case.  This attitude could signal other problematic behaviors down the line.  Throughout the process, be on the lookout for warning signs in experts’ tone, language, and demeanor.


Expert testimony is not a special favor to the trial team; your witnesses are being paid handsomely for their time.  So don’t you deserve the best fit for your case?

If there’s one thing we’ve learned about working with experts, it’s never to be lulled into confidence simply in the face of a long, illustrious career.  Your case is best served not only by their expansive knowledge but by their ability to be jury-friendly teachers of your key scientific points and themes.  Before you hire, make sure your great expert is also a great witness.

About the Author
Dr. Pitera presented this paper at the SEAK National Expert Witness Conference April 27-28, 2019 in Clearwater Beach, Florida.