Acting as an expert witness in a legal matter can be a nice way to compliment your practice. However, it is important to understand the role of experts, as well as their duties and obligations. Expert witnesses are called to testify on the basis of their specialized knowledge, not necessarily their direct knowledge of events and issues in the case.
Medical experts often play an important role in the evaluation, development, and preparation of a case long before it ever goes to trial. In some states, to even file a medical malpractice complaint a plaintiff is required to have the case evaluated by an expert and obtain a written report outlining why the plaintiff has a reasonable and meritorious cause for filing such an action.
There are different types of expert witness testimony. Experts can give opinion testimony as a physician who provided treatment to the plaintiff and whose conduct is not at issue. The second type of expert witness is a retained or controlled expert witness. This is a person giving opinion testimony after being retained by a lawyer on behalf of one of the parties to the lawsuit.
Before you give deposition or trial testimony, your opinions must be disclosed in writing and provided to the other parties in the case. In federal court, this is governed by Federal Rule of Civil Procedure 26. If the case is pending in state court, your written opinions are governed by local court rules. In both cases, the written opinions should be thorough and complete because you will not be allowed to testify to new opinions at the time of trial but will generally be allowed to expand upon those disclosed in writing at your deposition trial.
In order for a jury to hear your opinions at trial, your opinions must be reliable. In federal court, expert testimony is governed by Federal Rule of Evidence 702, which states:
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.
This means, that if a fact or evidence at issue involves scientific, technical, or specialized knowledge that is outside the scope of an ordinary layman’s experience, or involves complex issues challenging a layman’s comprehension, expert testimony is required. The scientific evidence must not just be relevant but also reliable. Expert opinions will be scrutinized to see if they are based on scientific testing or review of scientific data rather than just assumptions or speculation. Additionally, the experts must be qualified by their knowledge, skill, experience, training, or education. Given these parameters, it should come as no surprise that expert trial testimony is required for all medical malpractice cases.
Some states follow the “new or novel rule” which dictates that expert testimony is only admissible if the methodology or scientific principal on which the opinion is based is sufficiently established to have gained general acceptance in the particular field in which it belongs. This means that the evidence must be generally accepted as reliable in the relevant scientific community. New or novel techniques will be placed under the scrutiny of this standard. Courts will look at papers, books, journals, and case law to make a determination as to the reliability and general acceptance. Failure to meet the requisite standards may render a physician ineligible to testify.