The psychologist’s role as expert witness

At times, a psychologist will be called upon to be an “expert” witness in a case that may proceed to a court trial. Today in the United States, although the figures vary greatly from jurisdiction to jurisdiction, about 10 percent of cases started in a court actually proceed to a completed trial.

In any given court case, the psychologist could take on many roles. In addition to participation as an expert, a psychologist could be the therapist for a patient and be asked or required to testify in that capacity. As a therapist, the issues of patient privilege and waiver of patient privilege will be important. A psychologist may be asked to serve as a consultant to an attorney or to a testifying psychologist. Consultants have been used to help select jurors or to help prepare witnesses as to dress, demeanor or phraseology for trial or to review the presentation of psychological theories, practices and legal defenses.

Psychologists can also be appointed by a court to make either a diagnosis or a recommendation at the judge’s request. This column will focus on the role of psychologist as expert witness.

An expert should have special knowledge. For psychologists, this is usually evidenced by academic credentials, training, employment history, publications and licensure. In other fields, there are other ways to become an expert, e.g. life experience. The expectation is that an expert opinion will carry more weight, particularly with a jury. Often, however, both sides will employ an expert, so a jury may be left trying to decide which expert is more credible. Or they may discount both experts because they may not have a basis to believe one expert over another.

An attorney should not trust the expert to prepare alone. The attorney and expert should find time to work together to prepare for trial. They shouldn’t surmise that when the expert testifies, everything will be believed.

An expert is a teacher in that he/she does have specialized knowledge that a jury needs to accept and understand. This means that the testimony and expertise needs to be explained in terms that are clear and comprehensible to the jurors. The expert could consider using visual aids to instruct the jury in order to give the jury an imprinted message to remember. Things that are put into writing tend to be considered more important than words alone.

The expert also needs to be prepared for cross-examination. While on the witness stand, the attorney who hired the expert asks questions that are called the direct examination. Direct examination is usually limited to who, what, where, when, describe or explain. Do not be concerned with limitations or the types of questions if the attorney and psychologist have practiced enough before hand and understand their goals. The attorney and the expert should know before trial what testimony is expected at trial.

The questions asked by the attorney for an opposing party to the same witness are called cross-examination. These questions can be far ranging including going into a person’s credentials, prior testimony in the case (depositions), testimony in other cases, different theories, alternatives and other areas. Cross examination can include leading questions and can make assumptions. The expert will probably be asked about meeting with the attorney or attorneys before the trial and there will probably be questions regarding how much the expert is being paid. These questions are an attempt to put the ideas into the jury’s mind that the expert is biased or self-interested in the outcome. The directing attorney and the expert should discuss these issues before trial so the jury sees an honest and acceptable response to all questions.

Experts are important. They do not get to decide the ultimate issues of fact in a case; that’s the jury’s job. However, an expert can discuss a case with elements of this case and give an expert opinion within a degree of certainty within his/her field of expertise. Psychologists could have such expertise in many areas, including but not limited to: the ability of a defendant to work with an attorney to aid in the defendant’s own defense, issues of insanity, intellectual abilities and deficiencies, memory function, degrees of depression, diagnoses, mental capacity, incompetence and others. These issues can arise in criminal cases, civil cases, custody disputes, juvenile proceedings, commitment hearings and other types of cases.