Legal Issues : Testifying as an Expert

Qualifications of an Expert Witness

Before allowing a medical professional to testify as an expert, the judge will determine whether the individual possesses the requisite knowledge, skill, experience, training, and/or education to assist the jury.

You must always resist testifying beyond the limits of your expertise. An attorney, even a judge, may ask you questions related to your testimony but about which you are truly not an expert. Testifying is stressful. It is difficult for many to say, "I don't know" or "That is beyond my area of expertise." Giving a professional opinion beyond one's area of expertise is a clear violation of professional ethics.

Purpose and Scope of Expert Testimony

The purpose of expert testimony is typically to educate the court about a complex medical issue. Experts are allowed to testify on a variety of matters to "assist the trier of fact to understand the evidence or determine a fact in issue" (Federal Rules of Evidence §702).

Medical experts do not replace the judge or jury's determination regarding guilt. In criminal cases, experts are not allowed to testify, for example, that a victim or witness is telling the truth. A medical expert may give an opinion that a child's injuries could not have resulted from a fall, for instance, but may not give an opinion that a mother who stated a child fell, in fact, abused the child. Courts may vary in their determination of when an expert witness has gone too far. In preparing to testify, clarify this issue with counsel.

Forms of Expert Testimony

Medical expert witnesses are characteristically asked if their opinions are based on a "reasonable degree of medical certainty." Expert witnesses may rely on their observations and experiences in their clinical practice, medical literature, training, medical records and the like to formulate their opinions. Hypothetical questions may also be posed to an expert.

Expert testimony is often used to educate the judge and jury on principles that may be unknown to them. For example, many people are not aware that in cases of child sexual abuse, normal physical findings do not rule out the possibility of abuse. A medical expert, even if they did not examine the child in question, may be called to testify on the meaning of normal physical findings in an examination of a child who discloses sexual abuse.

Experts may be asked to testify in the direct offer of proof as when a prosecutor presents expert testimony as part of the direct presentation of his or her case. Expert testimony can also be used in rebuttal. For instance, after the treating physician's testimony and cross examination in a child sexual abuse case that a child's examination was normal, a medical expert might be called to clarify that normal physical findings do not rule out the possibility of sexual abuse. 

Preparing to Go to Court

There is no substitute for thorough preparation before testifying as an expert witness. The following steps will help you to testify in an effective, professional manner:

Be prepared to testify on your qualifications

Maintain a current, accurate curriculum vitae. Be prepared to articulate areas of expertise, educational background, specialized training received or provided, publications and experience.

Assemble information about:

• Educational background information
• Approximate number of children you have evaluated in your career
• Approximate number of similar cases you have seen
• Which journals you subscribe to and regularly read
• How many times you have testified
• If you have ever been declared an expert witness
• Approximate number of times you have testified for the prosecution and for the defense

Be familiar with relevant and current literature

Effective attorneys will be prepared to cross-examine you on current medical literature. While no one can be familiar with an entire body of literature, you should be familiar with well-known and well-accepted publications pertinent to the case. You should be able to clarify or correct the attorney's characterization of the literature and to apply or distinguish it from the case in question.

Know the case

If you are testifying about a case in which you were not involved, request that a complete medical record be provided for your review. The file should contain all the material necessary to form a reliable opinion. If you are the treating physician, be completely familiar with the medical record. You should also be familiar with any prior statements you have made, such as during grand jury testimony. You can ask for a transcript of your testimony to review prior to trial. You may request to use the file to refresh your memory while testifying.

Consult with the attorney who calls you as a witness

It is appropriate to meet with the attorney presenting the testimony before the court appearance. If the attorney does not initiate the meeting, you should do so. You should know whether you are being called as witness of fact or as an expert. You should be candid about your opinion, based on the evidence, and you should have basic knowledge about the attorney's theory of the case.

You may also educate the attorney about the issues to help them prepare. You and the attorney should discuss any exhibits that might be used. The attorney can assist you to anticipate questions posed upon cross-examination. You can also assist the attorney to recognize potential issues that may be raised. Clarify all questions about testifying before going to court.

Medical professionals should confirm they have the appropriate insurance (malpractice and/or errors and omissions policies) prior to testifying as an expert witness.