Expert Witness Qualifications

The qualifications required of an expert witness are governed by Federal Rule of Evidence 702, which states:

Rule 702. Testimony by Expert Witnesses

A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if:

(a) the expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue;

(b) the testimony is based on sufficient facts or data;

(c) the testimony is the product of reliable principles and methods; and

(d) the expert has reliably applied the principles and methods to the facts of the case.

It is important to note the conjunction “or” connecting “knowledge,” “skill,” “experience,” “training,” and “education.”  This means that under Rule 702 only one of the above five are needed, not all of them.  A common misconception is that one needs to have a PhD or to have gone to Harvard or Stanford to testify as an expert witness.  This is not true either legally or practically.  Many expert witnesses have no advanced degree and there are even a good number of expert witnesses who have no college degrees whatsoever (think Marisa Tomei in My Cousin Vinny).

Who is qualified to be an expert witness will ultimately be determined by the trial judge in the case at hand.  The trial judge acts as a gatekeeper in this regard.  The judge’s decision will be based on both the expert witness’s background/experience as well as the specific issues in dispute in the particular case. For more information on expert witness qualifications and how to qualify as an expert witness please see The A-Z Guide to Expert Witnessing.