What Makes a Person an Expert Witness in the Eyes of the Law?

An expert witness is someone acknowledged as possessing expertise in a certain area who relays facts, or, in some cases, opinions, and/or helps the jury understand them. Individuals may only serve in this function in federal legal cases if they meet the criteria laid out in the Federal Rules of Evidence, specifically Rule 702. This holds whether the person is an expert witness finance or an expert witness in automotive function.

Expert Witnesses Must Possess Suitable Qualifications

They must work in a field related to the issue they are brought in to testify about. They also need to be skilled in their chosen profession. However, simply saying their job is “such-and-such” is not enough. They must also be shown to have specialized knowledge by virtue of training, skill, experience, education or some combination thereof.

Expert Witnesses Must Add Value to the Case

If the person’s testimony does not contribute new, not immediately obvious information, then there is no point to it. The witness must provide reliable, helpful assumptions that somehow further the case.

Expert Witnesses Must Offer Proof

This includes non-ambiguous data and facts. Principles and methods used to gather these must be generally accepted by the community of experts. They must also be utilized correctly. Any opinion offered must be derived from accurate, pertinent information and a foundation agreed upon by professionals in the field. If a particular scientific issue is controversial, courts have to decide whether tests used are reliable. If they do not pass scrutiny, the testimony is inadmissible. There must also be a certain amount of data, though how much counts as “enough” is not judged by a set standard.

While expert witnesses in federal courts are dictated by the aforementioned Federal Rule of Evidence 702, in non-federal instances, regulations vary by jurisdiction. Some states, like Arizona, choose to apply the federal one. This is a simplified overview. Whether an individual can serve as an expert witness in court can get quite complicated, especially as relates to admissibility.