Hypnotized Witnesses Spark Legal Dilemmas

At first the woman remembered nothing of what had happened just before she woke up in a pool of blood. But six weeks later, under hypnosis, she told a dramatic story.

Her male companion had told her to get on the bed and strip, she said. Then he pulled out his switch-blade, threatened to kill her, and stabbed her repeatedly to “get even with you for running out on me.”

After undergoing the hypnosis, the woman submitted her story in an affidavit. She recalled for the first time that she had once danced with the man and then indeed had run out on him. On the basis of the woman’s story, police arrested a suspect.

But the tale was riddled with inaccuracies. Repeated stabbings wouldn’t have left her with only a single wound. She described the defendant’s maroon Triumph motorcycle, on which she had ridden, as a black Yamaha. She reported eating pizza at a restaurant that didn’t serve it. And it turned out the man she danced with was not the defendant.

Court Faced Question

That case made the Minnesota Supreme Court in 1980 face a question that has split state courts and mental health professionals: Is memory that emerges under hypnosis reliable enough to be used in court?

Minnesota’s high court was among the first of 13 to say no, but courts in 13 other states have ruled to admit such testimony, usually with procedural safeguards, according to Roy E. Greenwood, an Austin, Tex., attorney. Oregon state law permits it as well.

In December, the American Medical Assn. declared that recollections under hypnosis are too shaky for the witness stand. An AMA committee reported that it found “no evidence to indicate that there is an increase of only accurate memory during hypnosis.” Further, the committee’s report said, “there is no way for either subject or hypnotist to distinguish between those recollections which may be accurate and those which may be pseudomemories.”

Nationwide Ban Possible

Dr. Martin Orne, chairman of the AMA committee and longtime critic of such testimony, believes it will eventually be banned across the country as dangerously inaccurate. If so, that would “help, not hinder, the enforcement of law,” says Orne, psychiatry professor at the University of Pennsylvania and director of the unit for experimental psychiatry at the Institute of Pennsylvania Hospital in Philadelphia.

But Martin Reiser, director of behavioral science services for the Los Angeles Police Department and a supporter of the technique, says hypnosis is a natural human ability a witness can use to improve memory. He says the Minnesota case was an unfair example since it involved an intoxicated witness and a self-taught hypnotist.

Hypnosis has produced remarkable successes for police. A famous example is the 1976 kidnaping near Chowchilla, Calif., of 26 children in a school bus. Under hypnosis, the bus driver recalled most of the license plate number of a Dodge van he saw, which helped break the case.

Hypnosis also has helped rape victims provide “rather exquisite detail,” Reiser says, and has aided other witnesses in describing faces for police artists.

Dispute Over Accuracy

Such tips can lead investigators to new evidence. The controversy isn’t about that. The dispute is whether the overall story a hypnotized person tells is likely to be accurate enough to be used in court.

Any witness can lie or remember wrong and think he’s right. People can lie under hypnosis too. But a hypnotized person runs a greater risk of using imagination to fill in gaps in memory say opponents of hypnotism for testimony.

The problem, they say, is that hypnotism heightens the imagination. A mesmerized witness “sees” beliefs and suggestions in his mind. During and after the trance, they say, nobody can distinguish such imagined scenes from actual memories. The witness, convinced his phony memories are true, in turn becomes convincing about them in court, they say.

The imagined memories can be shaped by news reports about the crime and suspects, leading questions and even unconscious cues from the hypnotist or others, they say.

If a bystander at a hypnotic session clears his throat at a crucial point, “you’re giving messages to the subject” about how his tale is being received, says Helen Joan Crawford, president of the division on psychological hypnosis of the American Psychological Assn.

Increases in Memory

In all, Orne says, scientific studies show that hypnosis can increase the amount of material a person describes about an incident. It may produce new facts. But “if you get increases in memory, that means you get increased wrong and right memory, and typically more wrong than right.”

Some experts, however, are wary of laboratory results.

“Laboratory experiments do not address real life situations,” says Dr. Charles Mutter, a Miami psychiatrist who served on the AMA panel. They do not recreate the emotional charge of a crime, which may imprint memory more strongly and make it more accessible to hypnosis, he says.

Reiser, the Los Angeles police psychologist, says his department found that hypnosis elicited “somewhat to extremely accurate” information in more than 80% of the cases in which it could be checked. Police were able to follow up about 45% of the cases in which hypnosis was used, he says.

But scientifically, that measure of accuracy “means nothing,” says Donald Rossi, a psychologist who directs the behavioral science section of the Michigan State Police. The crucial question is what percentage of the statements from hypnotized witnesses is true. If hypnosis makes even 30% of the data from a witness accurate, “you’re doing really good,” Rossi says. “That’s why we look at it as only an investigative lead.”

High Percentage of Accuracy

Patrick J. Brady, a detective who directs the Boston Police Hypnosis Unit, says his experience shows hypnosis produces “a high percentage of very accurate information.” But he declined to estimate a percentage, saying statistics can be misleading.

As for hypnotism giving witnesses undue confidence in their stories, he finds “there’s nothing solidified in their memory” and they continue to show degrees of uncertainty. He also says he prevents leading questions or cues to the hypnotized person by knowing only the crime and its date when he begins a hypnotic session.

Mutter, the Miami psychiatrist, takes an additional precaution against phony memories by telling subjects that it’s OK not to remember everything. Otherwise, he says, “You’re saying they’ve got to come up with something” when a gap in memory appears, and imagination might fill it in, he said.

Others say a hypnotized person can still manufacture memories, simply from the belief that what he appears to recall is true memory.

Research on Recall

Research is finding other ways to improve recall. Studies at the University of California at Los Angeles, for example, show that memory can be improved by recalling the physical and emotional context of an incident, reporting even unimportant aspects, recalling events in different orders and imagining the scene from different perspectives.

In fact, those techniques and hypnosis were about equally effective in improving memory of crimes portrayed on film, says UCLA researcher R. Edward Geiselman. Both approaches increased memory without adding inaccuracy, he says. Geiselman says he doesn’t know if the non-hypnotic techniques could replace hypnosis. They are simpler and faster, but they may not overcome memory blocks in traumatized witnesses, he says.

Orne sees some promise in memory-jogging techniques if they avoid the drawbacks he finds in hypnosis.

Development of memory aids is “a legitimate request by law enforcement people,” Orne says. “It’s just that hypnosis is not the right tool for it.”