The admissibility of hypnotic evidence in U.S. Courts

For the past two decades, the American judiciary has confronted the admissibility of hypnotic evidence in criminal prosecutions. These courts have uniformly rejected the admissibility of out-of-court statements made while an individual is in hypnosis. In contrast, the courts divided sharply over the admissibility of hypnotically refreshed testimony. Some courts adopted a per se rule of exclusion; these courts, however, also carved out exceptions for testimony based on prehypnotic memory and testimony of the accused. Courts admitting hypnotically refreshed testimony adopted three different positions: (a) a "credibility" approach, which left the reliability issue to the jury; (b) a "discretionary admission" approach, which left the reliability issue to the trial judge; and (c) a "procedural safeguards" approach. In addition, constitutional concerns played an influential role in some of these cases. This diversity in the case law often resulted from a judicial failure to understand the scientific research on hypnosis. Courts have also considered the use of hypnosis as a basis for expert testimony about an accused's mental state. Unless the advantages of hypnotically refreshed testimony are significant, why add more problems?