Clients often ask whether retaining an expert witness is necessary in their case.  And they are wise to ask, because experts are a critical part of many cases, but not all. As attorneys, we often retain an expert “because we can” or “because that’s how we always litigate this type of case.”  But often we fail to ask ourselves the only question that matters: will retaining this expert improve my client’s chance of winning?  And let's face it, it’s comforting heading into trial with the added support of an expert, but it may be to your client’s detriment.

Generally, experts are needed when the subject matter of the case is more complex than the average juror would be expected to understand.  Under those circumstances, expert testimony is needed to explain the subject matter to the jury (or the judge, if the judge is the fact finder) to help them determine a fact at issue. An example is in a medical malpractice case where the jury might be tasked with determining whether the defendant-surgeon did—or did not—breach the standard of care when operating on the plaintiff.  The jurors are not likely surgeons, and therefore are not able to determine standard of care without expert testimony. In fact, in Arizona, expert testimony is generally required to prove standard of care in medical malpractice cases, except in the most egregious of circumstances.

If, however, the subject matter is “within the purview of the jury”—meaning that the average lay juror can understand the evidence and determine a fact at issue without the aid of expert testimony—such testimony is not only disfavored, it also may not be permitted by Rule of Evidence 702.  For example, we would all agree (or at least we should) that under most circumstances expert testimony on the color of a traffic light at the time of an accident does not help the jury and therefore is unnecessary.

The difficult circumstances are those where expert testimony is permissible, but disfavored (at least in this author’s opinion).  An example from a colleague’s recent case involved a pedestrian’s fall on the edge of a sidewalk in broad daylight, in an area frequently traveled by the plaintiff, and thus familiar to her.  Expert testimony on the issue of safety of the sidewalk was available (i.e., grading of the sidewalk, coefficient of friction, human factors associated with pedestrian walking patterns), but the strategic defense question became: did the jury want to hear an expert tell them whether the sidewalk was safe?  Would the jury view such expert testimony as condescending or belittling?  Ultimately, the defense strategy—rightly so—was to forego expert testimony, and instead encourage jurors to use their common sense in assessing the alleged dangerousness of the condition; and they did, returning a full defense verdict.

Turning to expert costs, everyone agrees that experts are expensive, often one of the most expensive components of the case.  And, frankly, if the expert is good enough to significantly impact the outcome of a case, he or she can command a higher rate.  Nevertheless, the retaining attorney can manage expert costs with a few simple steps:

1. Informally and briefly interview the expert about the case before formally retaining the expert. And as the attorney, I recommend not delegating this task—do it yourself.  This forces you to learn the case at an early stage.  Most experts will spend a few minutes discussing the issues with you and sharing their preliminary impressions.  This can save significant time and money by avoiding having to retain a new expert months into the case after learning for the first time that the expert is unsupportive.

2. Once retained, give the expert clear instructions on the issues you want the expert to focus on.  If the only issue is a discreet damages issue, avoid sending the expert voluminous documents on an unrelated issue and then be surprised when the big bill comes.  The attorney is obligated to provide the expert with pertinent information limited to that expert’s particular issue.  Moreover, experts have offices too, and they don’t want to be inundated with more material than is necessary.  Of course, if the expert asks for additional information for contextual purposes, you’re wise to provide it. 

3. Maintain effective and regular communication with the expert.  As with most aspects of litigation, picking up the phone to check in is usually beneficial.  And because written materials exchanged with a testifying expert are usually discoverable, the attorney is best-served by minimizing written communication.

The takeaway is that experts are often a necessary part of a persuasive, winning defense.  But if you can’t clearly articulate why the expert improves your odds of winning, do yourself and your client a favor: resist the temptation of retaining one.  And if you decide to bring an expert on board, remember to thoroughly vet the expert, because he or she could be a part of your life for years to come.