Cross-examination of prosecution witnesses for the Prosecution
Cross-examination of prosecution witnesses
The techniques of cross-examination of prosecution witnesses in a computer crime case are basically the same as in any other type of criminal case. The first decision the defense counsel must make is the general trial strategy.FN40 Where the strength of the defense case is reasonable doubt, any cross-examination that reduces the certainty of facts testified to by the prosecution's witnesses is helpful. Where the facts are not substantially in dispute, except for one key element upon which the defense will rest, it may often be desirable to leave the prosecution testimony unchallenged. Sometimes, it is easier to focus if the defense limits its thrust to a sole issue or a few issues.
In general, the major issues likely to arise in a computer crime case are: Identity of the defendant; Proof of how the crime actually occurred; Proof that the act complained of violates the definitions in the statutes; Proof that the defendant had the requisite intent; and Proof that a computer or computer system was involved.
In determining the type of cross-examination likely to produce the desired results, counsel must determine if the witness is neutral, against the defense, or, in the rare case, for the defense. More specifically, counsel will want to determine if the witness will admit that his or her testimony on direct examination can be qualified. Most reasonable unbiased people will at least agree to the possibility that their observations might have been faulty or limited in accuracy by any number of environmental, temporal, or other factors. It is assumed that the prosecution will present all the facts that support its version of the computer crime. It will seldom encourage qualification on the part of its witnesses. Therefore, it is appropriate to ask traditional questions; those relating to the witness's opportunity to observe, any notes the witness took at the time of the occurrence, and any changes in the version of the testimony between prior statements and the witness's testimony.
Where it appears to the defense attorney that the witness is a hostile witness, it is frequently useful to attempt to get the witness to intensify his or her commitment to the version of facts testified to on direct examination. This technique can be particularly effective if counsel can lead the witness to argue for a position that is inconceivable to a rational person. For instance, a prosecution witness testifies that she observed the defendant at a point of sale terminal for six seconds, and she is sure that there was more than enough time to observe what he or she was doing. The comment that three seconds would have been enough, or even two or even one, may be more damaging than the witness's admission that perhaps with a bit more time he or she would be surer that it was the defendant who made an entry to the computer at that time.FN41