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Monday, October 8, 2018

Forensic Hypnosis: Investigative Tool or Junk Science?

     Advocates of forensic hypnosis claim that crime victims and witnesses, under an hypnotic state, can remember events they have forgotten, and sharpen memories that are still with them. Forensic hypnotists are often brought into cases to help, for example, a witness or victim recall a license plate number, or an odometer reading. Investigators also use the technique to retrieve more detailed descriptions of suspects.

     Supporters of forensic hypnosis point to cases where its use has solve crimes. Detractors (myself included) can point to instances where hypnotically induced information turned out to be inaccurate, and even harmful.

     In the 1970s I was tangentially involved in an arson-murder case where a forensically hypnotized witness/victim identified an innocent man as the fire setter. In one of my own cold case murder investigations, a witness I had someone forensically hypnotize, produced information that led me on a wild goose chase. In Pennsylvania and several other states, hypnotically induced testimony, because it is unreliable, is not admissible in court.

     A lot can go wrong when a victim or a witness is questioned while in an hypnotic state. The hypnotist can unwittingly suggest information to the subject that taints the results. Under hypnosis, the personal beliefs and prejudices of the interviewee can seep into remembered accounts and descriptions.

     Researchers have found that people under hypnosis are fully capable of lying, and the process can bring to the surface a subject's false beliefs. Because of these and other problems with this investigative technique, I am not a fan of forensic hypnosis, particularly when practiced by psychologists who make their livings putting clients under to help them stop smoking, lose weight, stop taking drugs, or get off booze. In my opinion, composite sketches based on the memories of hypnotized eyewitnesses are, at best, useless. In the practice of criminal investigation, forensic hypnotists should be placed in the same category as fortune tellers, astrologists, and psychic detectives.  


  1. Hypnosis may help investigators gather evidence but, I agree, the subject should never be placed on the stand as a witness. I feel the same was about so-called "unchained memories" in which a person supposedly represses the memory of a crime because it was traumatic, and latter recovers "memory" of the incident. Here in PA, a quack named Alan Pass, PhD had a man convicted of murder by testifying to the validity of unrepressed memories. Apparently, Pass walked away from this with no consequences even though it was later discovered that he mislead the court about his credentials.

  2. Hypnotherapy can help you to escape from problem patterns of response and behavior to achieve greater flexibility and choice in your life. Hypnotherapy or hypnosis therapy works by allowing you to relax really deeply.

  3. Beware of persons who call themselves life coaches or use hypnotherapy to seize what they may call evidence from afar but is really private propery.

  4. The 1988 Texas Court of Criminal Appeals opinion in the Zani vs. State case, addressing the use of hypnotically enhanced testimony and establishing ten procedural safeguards, is arguably the most significant case related to the use of forensic hypnosis, other than the Rock case. In simple terms, the Rock case firmly established, under careful guidelines, the potential admissibility of information obtained using forensic hypnosis, and the Zani case more or less codified the guidelines, or protocols. The guidelines established by the Zani case are the foundation upon which all forensic hypnosis investigation is conducted. The guidelines are:

    • The level of training in the clinical uses and forensic applications of hypnosis by the person performing the hypnosis.

    • The hypnotist’s independence from law enforcement investigators, prosecution, and defense.

    • The existence of a record of any information given or known by the hypnotist concerning the case prior to the hypnosis session.

    • The existence of a written or recorded account of the facts as the hypnosis subject remembers them prior to undergoing hypnosis.

    • The creation of recordings of all contacts between the hypnotist and the subject.

    • The presence of persons other than the hypnotist and the subject during any phase of the hypnosis session, as well as the location of the session.

    • The appropriateness of the induction and memory retrieval techniques used.

    • The appropriateness of using hypnosis for the kind of memory loss involved.

    • The existence of any kind of evidence to corroborate the hypnotically enhanced testimony.

    • The presence or absence of overt or subtle cuing or suggestion of answers during the hypnotic session.

    Assuming these guidelines are adhered to, if the trial court finds by clear and convincing evidence that the hypnosis neither rendered the witness’ post-hypnotic memory untrustworthy, nor substantially impaired the ability of the opponent fairly to test the witness recall by cross-examination, the testimony may be admitted.

  5. In Pennsylvania it seems we have a situation that can almost be described as a “vacuum” in regards to hypnotically refreshed testimony. Almost no case law exists. Of course defendants may use hypnotically refreshed testimony, due to the Supreme Court ruling in the Rock case. Once you look outside of the parameters of hypnotically refreshed memory which was granted to defendants in Rock, the pickings are very slim.

    What little there is in the Pennsylvania code related to hypnotically refreshed memory is contained under Rule 601 – Competency. And in actuality the issue of hypnotically refreshed memory is addressed because of a clarification that Rule Pa.R.E. 601(b) does not address the admissibility of hypnotically refreshed recollection. Instead, the “clarification” it cites is Commonwealth v. Nazarovitch, 496 Pa. 97, 436 A.2d 170 (1981), in which the Supreme Court rejected hypnotically refreshed testimony, where the witness had no prior independent recollection. Of course if a witness does indeed have absolutely no prior recollection at all, then it’s difficult, even maintaining the standards set up by the Zani case, to get anything subsequently remembered to be entered into evidence.

    The clarification of Pa.R.E. 601(b) continues by citing the application of the test of Frye v. United States, 293 F. 1013 (D.C. Cir. 1923) for scientific testimony, wherein the Court was not convinced that the process of hypnosis as a means of restoring forgotten or repressed memory had gained sufficient acceptance in its field. However, the Frye per se exclusion has more or less been replaced by the rulings in the Rock and Zani cases, with Zani setting the new standards for collecting admissible evidence.

    The clarification of Pa.R.E. 601(b) continues by citing Commonwealth v. Nazarovitch, supra; see also Commonwealth v. Romanelli, 522 Pa. 222, 560 A.2d 1384 (1989) (when witness has been hypnotized, he or she may testify concerning matters recollected prior to hypnosis, but not about matters recalled only during or after hypnosis); Commonwealth v. Smoyer, 505 Pa. 83, 476 A.2d 1304 (1984) (same). Pa.R.E. 601(b) is not intended to change these results. Based on a growing national body of case law regarding the admission of hypnotically enhanced memories when properly collected/recorded using the Zani guidelines, it would seem that Pennsylvania law is ripe for change in this area, as it’s been over 20 years since any real “new” Pennsylvania case law has been written on the subject.