Witness preparation—Expert witnesses

Witness preparation—Expert witnesses

In preparing expert witnesses, it is important to keep in mind that counsel should learn the basics, but not consider himself or herself an expert; that counsel should be clear on the limitations of his or her expert's expertise and make sure that his or her expert can be understood.

Before attempting to present expert testimony, the defense attorney should become well versed in computer crime. This information is likely to include an understanding of the typical kinds of computer crime cases,FN75 the most publicized computer crime cases,FN76 the meaning of a systems approach and the associated techniques of flow charting and systems analysis,FN77 and how the documents the prosecution will attempt to have admitted into evidence are produced in the computer system involved in the case.FN78

As in other types of trial preparation, defense counsel must be wary of overestimating the value of his or her education. It is better to appear totally ignorant and ask questions that will educate the jury as to the keypoints in the defense rather than to testify through the expert. Experts are usually quite content to be the source of all information, and will suffer counsel's ignorance with great patience.

Computer crime involves not only computers, but accounting, security, and other areas of expertise. Counsel runs the risk of embarrassing cross-examination by the prosecution if he or she allows an expert witness to stray into areas where the witness is not expert. Therefore, at the initial meeting with the expert, it is important to understand the limits of the expert's testimony.

The greatest liability of an expert is the possibility that the expert will not be understood. In order for the jury to find the testimony of the expert convincing they must understand it. If counsel has "over-prepared," and cannot appreciate the difficulty that the jurors experience in listening to the expert, it is a good idea to have a secretary, wife, husband, or other uninterested party who is not expert in computer matters listen to the expert. If they are confused, it is predictable that the jury will be confused as well.