The following article appears in the journal JOM, 46 (9) (1994), p. 72. JOM is a publication of The Minerals, Metals & Materials Society

So You've Been Asked to Be an Expert Witness

Individuals often become involved in litigation either by initiating litigation against someone or having litigation brought against them. Aside from being in the legal profession, however, there are other ways to become involved—for example, the person could be a fact or expert witness. Fact witnesses are involved in trials as a result of their having direct knowledge relevant to the issues in a case. For example, an inventor may be called upon in patent infringement litigation to testify regarding facts involved in the creation of the invention. Fact witnesses may testify either because they have volunteered to do so or because they have been required to testify through the serving of a subpoena.

An expert witness is not called to testify because of prior involvement in activities that precipitated the litigation. The expert testifies because he or she has knowledge, skill, experience, training, or education, and has expertise that may be meaningful to a party in attempting to prove its side of the case. An expert testifies voluntarily by agreement with one of the parties or the court.

A key distinction between fact witnesses and expert witnesses is that an expert witness may provide an opinion. Fact witnesses must limit their testimony to facts, except for opinions that are either rationally based on an actual perception of the witness or might otherwise be helpful to an understanding of their testimony.

Before one can testify as an expert witness, the qualifications of the individual as an expert must be established. No single credential provides a universal basis to qualify one as an expert. One looks at many factors, such as the area of educational specialization and whether any graduate degrees were obtained. Also, extensive, meaningful work experience is considered.

Work experience may be of many types. For example, if one were looking for someone knowledgeable in the properties of aluminum castings, an expert might be one who has worked in research and development in the field, or has industrial plant experience in the field, or has been a professor of metallurgy. In addition, publications, patents, honors and awards, positions in professional associations (including relevant committee work), as well as all other factors that support the person's status as an expert are also considered.

From an attorney's standpoint, an expert is also evaluated on his or her skill as a witness. An attorney would evaluate the expert's ability to use good judgment in analyzing facts, express him- or herself clearly, express complex material in a fashion that readily can be understood by those who do not have expertise in the field, and handle intense cross-examination by opposing counsel.

Assuming that one has the credentials to serve as an expert and has been asked to become involved in a case, counsel will wish to meet with the potential expert and review the case and areas of testimony to ensure that the expert agrees with the attorney's theory of the case and conclusions. If not, the expert obviously cannot honestly and effectively function in that role in that case.

Assuming that one has agreed to serve as an expert and has been engaged by counsel to do so, the expert will generally review extensive materials relevant to the case. Meetings will be held with counsel to discuss areas of contemplated interrogation and possible cross-examination as well as the need for possible physical tests or research that will be performed by the expert or under his or her guidance and control. Also, the selection of exhibits that will be used at trial will be considered and documents will be reviewed. The positions of the opposing side will also be evaluated.

At some point in the early stages of the proceedings, the expert will provide a report outlining the areas of the expert testimony. Also, during the pretrial period known as "discovery," opposing counsel will generally wish to take the deposition of the expert. A deposition involves a series of oral questions asked of the expert. The expert's testimony is taken under oath and will be recorded by a court reporter who will generate a transcript of the testimony that may be reviewed by the expert. Counsel for the party who has engaged the expert will have an opportunity to cross-examine the expert at the deposition to clarify points or elicit additional information.

At the trial, the expert will be asked by counsel, on behalf of the party that has engaged the expert, to recite his or her qualifications as an expert in a particular field. This is followed by the testimony. The testimony may consist of the expert responding to questions providing facts or opinion or both. For example, if the expert is asked to define the term "stress corrosion" or to state the melting point of a particular alloy, these are questions that request factual information. On the other hand, the expert might be asked if, in his or her opinion, the failure of a given part was due to stress corrosion. In addition to the expert's principal role in providing testimony, an expert frequently may consult with counsel as to various theories of a case and whether the theories are sound in respect of the expert's area of skill.

An expert may be asked to sit in and observe the trial in order to gain a better understanding of the case and also to provide ongoing assistance to counsel.

In a given case, there may be a number of experts involved. For example, in a patent infringement trial, the patentee may engage a technical expert to provide expert testimony on the technology involved in the invention, the prior art, and the product alleged to infringe. There may also be a patent expert engaged by the patentee to provide testimony regarding the patent law standards to be applied in the case and opinions regarding the applicability of the laws to the facts of the case. Also, the patentee might have a financial expert to provide testimony regarding the amount of compensation to which the patentee would be entitled if the patent is found to be infringed. Opposing counsel frequently will seek to provide opposing expert testimony for each of these categories.

Unlike a fact witness, an expert is entitled to compensation for participation in the case.

A word of caution is appropriate. With the nature of court schedules being what they are, one cannot with great certainty tell an expert well in advance of the trial that the trial will definitely be held on certain dates. Also, even during the trial, there may be some shifting of the precise time period during which the expert will testify. It is also fairly common to set dates for depositions and to have those dates rescheduled because of conflicts.