Although the term “voir dire” is generally associated with the examination of prospective jurors, it’s also used to describe questioning of opposing experts to determine whether they should be allowed to testify. Voir dire of the expert takes place after opposing counsel attempts to qualify the expert (see Evid C §§720(b), 721), either in or out of the jury’s presence (see Evid C §402).
Voir dire of experts can be used to
- Show that the expert is unqualified to testify. Experts are infrequently found to be unqualified to give testimony, but they may be found qualified to testify in one field, e.g., accident reconstruction, but unqualified to testify in another field, e.g., suitability of an automobile design.
- Block opinions based on improper matter. Expert testimony is inadmissible if the expert’s assumptions aren’t supported by the factual evidence in the case, or if they’re otherwise based on insufficient or inadmissible matter.
But even if one of these purposes arise, use voir dire of experts very selectively because it can hurt your case by (1) irritating the judge and jury by taking up time, and (2) giving the witness and opposing counsel a preview of things to come on cross-examination.
If you decide to conduct voir dire of an expert, you’ll need to decide whether it should be in or out of jury’s presence (either is allowed under Evid C §402). It’s generally better to do voir dire of an expert outside of the jury’s presence, because the purpose of the voir dire is to keep the jury from hearing certain evidence. If you question the expert in the jury’s presence, it will be obvious to them that you’re trying to keep the opinion out, and the subject matter may be unduly emphasized. And if the judge ultimately admits the testimony, the jury may interpret that ruling as an implied endorsement of the expert and his or her opinion.
But in some cases you may want to use voir dire to discredit the expert before the jurors, even though you know the judge will allow the expert to testify. For example, you may choose to attack an expert by questioning him or her about classes failed in college, or misleading and incorrect entries on a resume.
For more on voir dire examination of an expert check out CEB’s California Expert Witness Guide §§14.4-14.7. And get step-by-step guidance on handling an opponent’s expert at trial in CEB’s Handling Expert Witnesses in California Courts (Action Guide).
Other CEBblog™ posts you may find useful:
- 5 Areas for Questioning an Expert at Deposition
- The Best Way to Attack an Opposing Expert
- 4 Ways to Attack Expert Testimony
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