Forensic Hypnosis: More Cons than Pros?

For courts, trance induction in eyewitnesses is a controversial tool.

Posted Sep 17, 2018

K. Ramsland
Source: K. Ramsland

In 1986, a woman in New Jersey was raped. Because it was dark, she couldn’t recall many details but she believed her attacker was black. She was hypnotized to try to improve her memory. Although she said she had not seen his face, she picked out a photo of Clarence Moore, a married father of three who owned a business and had an alibi. He was nevertheless convicted.

During legal wrangling in this case in 2005, three experts debated over the use of hypnosis. The state’s expert acknowledged problems with hypnosis but said the key issues were about memory, not the tool. One of two defense experts testified that hypnotically induced testimony was not reliable and that hypnosis adversely affects accuracy. The other called for a ban on hypnotically enhanced testimony.

In 2006, the trial court ruled that hypnotically enhanced testimony should be inadmissible. Two weeks later, the New Jersey Supreme Court agreed and issued an order barring this practice in criminal cases. On August 10, 2006, the prosecutor dismissed the charges against Moore. However, his life had been ruined.

He’s not the only one.

Having used hypnosis in therapy, I once believed that the guidelines debated in the Moore case and described below were sufficient safeguards. The more I've learned about research on human memory and cognition, the more I, too, resist the forensic use of eyewitness memory enhancement, especially by non-professionals trained in weekend certification seminars.

The US Justice Department offers a statement about using hypnosis in a legal context, i.e., that “in certain limited cases, the use of forensic hypnosis can be an aid in the investigative process.” Yet memory enhancement for eyewitnesses “is subject to serious objections and should be used only on rare occasions.” The information obtained “must be thoroughly checked as to its ultimate accuracy, and corroborated.”

The convoluted history of forensic hypnosis is partly due to inaccurate assumptions about human memory, i.e., that, like a video recorder, memory stores our experiences exactly as they occurred. Guided hypnotic enhancement can, therefore, retrieve those memories that seem to have been forgotten or repressed. Sounds sensible, right? But it's not that simple.

The courts are divided over the admissibility of hypnotically enhanced memories. Twenty-eight states have adopted a per se rule of exclusion, but some make exceptions. Courts that do admit it have adopted one of three basic positions: a) let the jury sort out its reliability, b) let the trial judge determine its reliability, and c) adopt "procedural safeguards" for its use.

Precedent-setting cases highlight its history. In Harding v. State (1968), the victim of a shooting and attempted rape identified her assailant only after she was hypnotized. The Maryland Supreme Court decided that hypnosis was like any memory aid device and allowed it.

Later, some courts took a more restrictive approach. In 1978 in New Jersey, someone wielding a knife attacked Jane Sell. She escaped but could recall no details. When psychiatrist Herbert Spiegel hypnotized her, she identified her attacker as her former husband, Paul Hurd, the father of her two children. The evening before the assault, Jane’s current husband, David Sell, had argued with Hurd. It seemed to logically add up.

But Jane wasn’t so sure. The detective encouraged her to accept her identification to protect her children, so Hurd was arrested and charged. His defense attorney argued that psychiatric suggestion during hypnosis had tainted Jane Sell’s testimony. The New Jersey Supreme Court decided not to allow her testimony. Their debate resulted in restrictive guidelines for the use of hypnosis to refresh eyewitness memory.

Accordingly, hypnotic sessions must involve a psychiatrist or psychologist trained and experienced in its use, and this professional had to be independent of all parties. Information given to the hypnotist should be written or recorded, and the interviews and hypnotic session(s) had to be video- or audio-taped. Only the expert and witness should be present during hypnosis, and the subject’s pre-hypnosis memories should be recorded before the procedure is used.

Some states view these safeguards as too weak. (In the Moore case above, the guidelines from the Hurd case were found to be insufficient.)

Problems with hypnotically enhanced memory include the possibility that a "recovered" memory is incomplete, inaccurate, or based on a leading suggestion. There also might be hypermnesia or confabulation—filling in the gaps with false material that supports the subject’s self-interest. Also, personal beliefs and prejudices can influence how an event was initially encoded and/or how the subject interpreted it during recall. More alarming is “memory hardening,” which occurs when a hypnotically induced false memory seems so real to the subject that he or she develops false confidence in its accuracy. It cannot be distinguished from genuine memories.

Today, the consensus among memory researchers is that memory is not recorded. Rather, it's constructed from many sources, such as experience, beliefs, and personal schemata. Therefore, hypnosis will not necessarily restore "forgotten" parts. Over the years, scientific support for the technique has eroded significantly, especially after many cases of hypnotically refreshed memory of "repressed" sexual abuse during the 1980s and 1990s were proven to be fabricated (Paterline, 2016).

Yet, some courts have not shifted along with professional consensus. In 1987, the U. S. Supreme Court reviewed a case from Arkansas in which hypnotically refreshed testimony had been rejected per se, in accordance with state law. Vickie Lorene Rock had shot her husband in 1983 during a fight. She claimed it was an accident, but she could not recall the details. She'd tried to leave their apartment, but her husband had begun to choke her. She'd picked up a gun, and while he hit her, she shot him. She thought her finger was on the hammer, not the trigger, but the gun had gone off anyway.

Rock twice underwent hypnosis by a trained neuropsychologist, who first interviewed her for an hour in recorded sessions. Rock recalled that her gun had misfired during the scuffle. A gun expert affirmed the possibility. However, the judge barred the refreshed memory, so Rock was convicted of manslaughter. Enter the U.S. Supreme Court, which found that a wholesale ban restricted Rock’s Sixth and Fourteenth Amendment rights. Hypnosis has its weaknesses, the Court stated, but to totally exclude it was arbitrary.

Thus, despite scientific research that highlights more cons than pros, some jurisdictions continue to accept hypnotically enhanced memory as viable testimony.


Paterline, B. A. (2016). Forensic hypnosis and the courts. Journal of Law and Criminal Justice, 4 (2), 1-7.