The technique of hypnosis may be useful in criminal investigations and under circumstances involving functional memory loss. Hypnosis cannot be used, however, to ensure the truthfulness of statements, particularly in a forensic context, because subjects may simulate hypnosis and are able to wilfully lie even under deep hypnosis. The most troublesome problem is the impossibility of distinguishing between actual memories and confabulations, either by the subject or by the hypnotist. While potentially useful to refresh witnesses' and victims' memories to facilitate eyewitness identification, hypnosis is relatively safe and appropriate only when the subject, the authorities, and the hypnotist do not hold any preconceptions and the identity of the criminal. If such preconceptions do exist -- either based on information acquired before the hypnotic procedure or on information subtly communicated during the procedure -- hypnosis may readily cause subjects to confabulate the persons suspected into their hypnotically enhanced memories. These pseudomemories, originally developed in hypnosis, may come to be accepted by subjects as their actual recall of the original events; the memories are then remembered with great subjective certainty and reported with conviction. Such circumstances can create convincing, apparently objective eyewitnesses, rather than facilitate actual recall. To reduce the likelihood of such an eventuality and other serious potential abuses of hypnosis, minimal safeguards should include allowing only a psychiatrist or psychologist with special training in hypnosis to conduct the sessions. A total of 60 references and German, French, and Spanish abstracts are appended. (Author abstract modified)