Judges GavelAs a trial lawyer, I spend time reflecting on expert witnesses from various subject matter disciplines to trends to core strategies.  For this four-part series, I thought I would share some thoughts about the tougher challenges litigation attorneys face in the presentation of expert witnesses at trial.  This blog post, Part One, considers the impact of expert witness testimony on a jury.  Part Two, on eliciting persuasive testimony.  Part Three, on doing conflict check with the right expert witness.  And Part Four, being outspent by the opposition.  In each, I’ll raise questions and look at them from several, different angles.


“Persuasive testimony.”  If only it were a word we could look up in a math book and have a formula for each element that leads to satisfaction of each variation on the burden of proof.  The very notion of expert testimony being “persuasive” implies a subjective element of swaying someone’s opinion to a desired conclusion.

What becomes particularly interesting about an expert witness testimony relative to winning a case is a question of proportion: relative to all the evidence that will be put forth, how much impact will the expert witness produce?  For example, if your case involves care of an elderly patient at a hospital, and your expert witness in medical malpractice is just one of ten witnesses with more than qualified credentials, does the expert witness only account for one-tenth of the desired outcome? Instinct and experience accounts for ‘more than one-tenth,’ but just how much more?

We forget who we are as lawyers, just how much more impact the expert carries to a lay jury.  The fact is, trial lawyers who engage in litigation have a certain self-confidence, along with a capability to master and present various subject areas outside of just the legal parameters.  We neither prepare for, nor process the impact the expert witnesses will have on the jury.

It should be no surprise that in post-trial jury interviews, it is often the expert witness testimony on one or both sides that is the first thing discussed.  While any one witness, including those with similar credentials but not designated as an “expert witness,” contributes one piece, the expert witness is the witness who ties it all together.  In other words, if there are nine medical witnesses and one expert witness, we might be able to say that the expert witness testimony could be ten times more important than any other single witness you present.

When we think of the expert witness in these terms, it allows the trial lawyer to strategically allocate preparation time going into the trial.  The lawyer must be conscious of and ready to go with every witness, but needs to spend that much more time with the expert witness to fight for every bit of persuasive impact.  When we are conscious of the potential impact of our actions, we can more thoughtfully prepare.

By: Paloma A. Capanna, Attorney at Law, Policy Analyst