The role of expert witness provides opportunities for public service and professional development, but it has its dangers. Many people regard expert witnesses as charlatans whose testimony is bought, and who will say anything to get their extraordinarily high fee. The spectacle of two supposed experts vehemently disagreeing on an issue in court only fuels that image. Certain areas of litigation tend to produce "professional" witnesses, but too-frequent testimony from a particular bias can make such an expert appear self-serving.
It is vital that scientists improve their effectiveness as witnesses to make the most out of the experience professionally and personally and to bring their best to the judicial process of which they are a part.
There is much discussion of how well any one expert's testimony represents the mainstream of thought in a given field. You must decide where you fit in the range of opinion in your field and tell your attorney in terms he or she can understand. Several professional societies and state boards—although not all— provide accreditation, but this certification is not for the purpose of creating an expert witness per se. This has sparked controversy about the extent to which boards and societies may be responsible for policing the pronouncements of those so certified, the identification of policy positions within the body of a profession, and the resources needed to promote and carry out the accreditation itself.
In addition to these formal and informal professional responsibilities, the expert may be subject to criminal and civil penalties for committing perjury, fraud, malfeasance or conspiracy in the course of testimony.
Setting the Fee
If you donate your services, be careful not to compromise your credibility through too close an association with the cause. Remember that you are a disinterested expert witness, not a crusader. Also, be sure to consult with a tax expert to find out whether your donated services (including expenses you incur) are deductible.
Preparing the Testimony
The gathering and review of evidence (called "discovery" in the legal process) is a critical step and is the joint responsibility of lawyer and expert. The latter is particularly responsible for the chain-of-possession of evidence (the physical handling of samples and their subsequent analysis), the quality of the work performed, including the appropriate use of controls and methods, and the professional interpretation of its meaning. Often, because litigation may begin long after the incident or action involved, the expert cannot obtain evidence of optimal quality and in the desired form. Describing the principles of evaluation to the attorney (who may not be informed about professional standards in this area) is an important part of being an expert.
At times, you must analyze or draw conclusions from the work of others. In such cases, you are not only free to point out any flaws, but are also professionally obligated to reject any evidence you cannot or are not willing to defend. That is the essence of the expert's role.
You may also need to examine articles published in the peer-reviewed scientific literature. In general, the courts place high value on these articles. However, you may also have to examine the "grey literature" of talks, presentations at meetings, informational pamphlets, and similar materials that lack the standing of peer-reviewed documents. These sources can contribute legitimately to your professional opinion in the same manner as other evidence that does not meet the highest professional standards. Remember, however, that if you represent your expertise as based on that material, your professional opinion will be on the line.
The affidavit is usually the first step in contributing as an expert witness. It is essentially a statement of your professional opinion about the facts of the case, but may include the evidence and other materials you have prepared. Since the affidavit is used by your attorney in litigation, he or she must have a say in its direction and contents. On the other hand, it is a statement of your expertise.
A deposition is a statement under oath, usually done at the request of the opposition, in which you outline your qualifications and the basis for the affidavit. You may be asked to give your professional opinion about the evidence you have prepared and about the interpretation of that evidence both in the context of the litigation and in terms of the whole body of relevant scientific knowledge. The deposition will be used by the attorneys in conference with the judge in pretrial proceeding. Opposition attorneys will have access to it and any related documents you provide your attorney (including correspondence). It may or may not be referred to in a trial or hearing, but it creates part of the basis for the trial.
Part of the preparation for being an expert witness consists of "woodshed drills" by your attorney. These simply prepare you to say what you know (and don't know) in a manner that is understandable to the court and jury simple, with you answering just one or two questions. Your attorney will review your appearance, voice modulation and vocabulary.
They are not designed to put words into your mouth or to train you to say only what your attorney wants the court to know. These drills also let you practice responding under cross-examination.
The attorney may plan for your testimony to be elaborate, with professionally designed exhibits, or with you at this time. He or she may also review your curriculum vitae with you, to eliminate areas that might cause you and the case problems (for example, associations indicating probable bias, overreaching claims of expertise, and so forth).
Testifying Under Oath
After you have been sworn in and have taken the stand, your attorney will briefly review with you your qualifications, usually taken from your curriculum vitae. This portion of testimony gives you a chance to settle down to the task before you.
The tactics used by your attorney and the opposition during courtroom examination will obviously vary depending on circumstances. You will be best prepared if you have listened to your attorney's opinion of the merits and strengths of your testimony during your woodshed sessions. Remember, also, to apply the K.I.S.S. principle ("Keep It Simple, Stupid"). You don't need to impress the court with your knowledge. If you are confident in your knowledge of the material at hand, you can set aside any irritations and challenges and frame your responses as simple propositions. The best model for an expert witness under examination is that of a teacher of adult pupils.
Knowledge is might, but might does not always make right. You may not be on the winning side, even if you are technically correct, judiciously responsive and thoroughly convincing. On the other hand, your side may prevail, perhaps largely through, or even in spite of, your efforts. Most litigation is settled out of court and you may not be informed of the result if you are not a party to the dispute. The expert witness is, after all, essentially a servant of the court system and should take professional pride in doing his or her best.
Little has been published on the role of the scientist as expert witness, but the following four resources offer more detailed information.