Hypnosis, while prevalent in popular culture, is a widely misunderstood process. Although portrayed as a sort of mind control through sleep, in actuality it is a trance state with an increased susceptibility to suggestion. It has also been used to recall memories that the subject had thought had been forgotten.
Hypnosis, while effective in memory recall, is also prone to false memories.
While many individuals have successfully recalled memories they thought had been forgotten, false memories are also common. Because of this, in 1984 the American Medical Association stated that hypnosis does not produce reliable recall. Even though the hypnosis can help a person remember additional details, there is no way of determining what is and is not accurate. Hypnosis expert, Tom Mauriello, was able to hypnotize students in in his criminal justice class and have them remember the names of their first grade teachers, which before hypnosis they had forgotten. He does admit that occasionally participants recall false information.
There are no clear guidelines for hypnotically obtained testimony and evidence in court.
Currently, the admissibility of testimony and evidence retrieved through hypnosis varies by jurisdiction. There is no universal decision on whether or not hypnosis is acceptable method for uncovering the truth. In jurisdictions where it is allowed but questioned, there are many criteria for reliability that the process must meet. In three states, it is completely inadmissible, and in four states it is completely admissible. The rest of the states have varying degrees of regulations, which shows just how divided an issue it is.
Hypnosis has been an productive aid in criminal investigations.
While it may not admissible in court, most agree that hypnosis is helpful in investigations by hypnotizing both victims and witnesses. Hypnosis allows for the participant to recall traumatic events without emotional interference. Famous cases where hypnosis has been used are that of Ted Bundy, Sam Sheppard, and the Boston Strangler.