A brief primer on forensic hypnosis

In the November Reasonably Suspicious podcast, my colleague Amanda Marzullo and I discussed a capital case out of Dallas - Ex Parte Flores - in which the Dallas PD used hypnosis on the primary witness, who ultimately switched her story. She at first said a long-haired white man was the perpetrator before identifying a short-haired Hispanic man (Mr. Flores) at trial.

On the podcast, we marveled that DPD had access to an on-staff hypnotist, wondering whether DPD might also consult Tarot card experts or palm readers? But Grits underestimated the level of official status that "forensic hypnosis" has achieved in Texas, by quite a bit! I'm putting these links up mostly for my own purposes, but thought Grits readers may also be interested, so here you go:

For starters, to be clear, most states (28) do not allow hypnosis-influenced testimony to be admitted into evidence at all. Of the states that do, Texas has over the years had one of the more robust programs. The Texas Court of Criminal Appeals approved the use of hypnosis in a case called Zani v. State from 1988, the year after  the Texas Legislature via SB 992 ordered what was then the Texas Commission on Law Enforcement Officer Standards and Education (TCLEOSE) to create an "Investigative Hypnosis certificate." (See a 2015 synopsis of their 50-hour training course, and here's the relevant section of the Occupations Code.)

The CCA reaffirmed the use of hypnotically induced testimony in a 2004 case, State v. Medrano.

The best journalism on this topic that your correspondent has seen came from Andy East at Reporting Texas in December 2014, in a story I'd missed when it came out. According to Mr. East:

Texas and 21 other states allow court testimony by witnesses who previously were hypnotized to enhance their memories, according to a study by Steven Lynn, a professor of psychology at Binghamton University in New York. The Texas Rangers have used hypnosis 66 times since 2009, according to the state Department of Public Safety. Most law enforcement agencies in Texas don’t keep statistics on hypnosis.

Further:

Investigative hypnotists in Texas must be certified by the Texas Commission on Law Enforcement. That requires taking a 50-hour course and passing an exam. Since licensing was mandated in 1987, commission records show that 858 law enforcement officers have been certified . Four officers have been certified in the past two years. In October 2013, the commission began requiring licensed investigative hypnotists to take a refresher course every two years.

According to an article by a former DPS trooper and prominent forensic hypnotist (touting the "Texas model" and outlining a "Road Map to Admissibility" for hypnotically enhanced witness testimony), some 80 police officers participated in the first TCLEOSE training once the official certification was created.

There is actually a Texas Association of Investigative Hypnosis, and regrettably we just missed their annual conference! That would have been a hoot. Here's a website of a prominent practitioner and former DPS trooper.

American Public Media in 2016 took on the story from a national perspective. They warned that:

Especially if done poorly, the process - basically a means of trying to induce a more focused state of mind — can plant memories or skew existing memories. It can also make witnesses or victims more certain of what they saw, even if the recollections turn out to be false. Today, hypnosis is a rare feature in police work and even rarer in the courtroom, partly because so many courts have ruled "hypnotically induced" testimony inadmissible. The process is viewed as roughly on par with another quasi-scientific investigative tool, the polygraph test.

They noted that, "Minnesota was one of the first to restrict such testimony when the state Supreme Court ruled in State v. Mack, in 1980, to bar testimony recalled for the first time under hypnosis." Here's a Candadian case from 2007 declaring post-hypnosis witness identifications inadmissible.

Over the years, scientific support for the technique has eroded significantly. These days, a 2016 academic analysis concluded, "Scientific research ... suggests, fairly overwhelmingly, that hypnosis does not reliably increase the accuracy of eyewitness recall and recognition; rather, the research shows that when effects do occur, hypnosis can produce an increase in false, distorted, or manufactured memories."

Further, said the same source: "it is not only the distortion of memory which is at issue, but also the sincerity with which people believe their distorted memories to be accurate. Because hypnotically recovered memories are remembered in such detail and with such emotion, subjects often develop false confidence in it."

According to this academic analysis (FN 35), there are at least five DNA exonerees who were convicted after information about hypnosis-induced testimony was concealed from their juries!

A DOJ manual for US Attorneys informs practitioners, "The information obtained from a person while in a hypnotic trance cannot be assumed to be accurate."

Memory expert Elizabeth Loftus has shown that hypnosis can be used to implant memories of things that never occurred.

Most academic papers I've found on forensic hypnosis are behind paywalls. The abstract to this 2015 academic paper suggests that hypnosis poses more risks of error than other memory recall methods. Another academic paper suggested more errors occur from hypnosis when the contents of memories are very emotional.

As far as Grits can tell, this is junk science at its worst. In Zani, ironically, the CCA already understood that proponent's claims had been seriously challenged: The majority opinion observed that:

Proponents of the use of hypnosis to restore a crime victim's memory to facilitate his trial testimony, most notable of whom is Dr. Martin Reiser, a psychologist and forensic hypnotist with the Los Angeles Police Department, advocate a "videotape recorder" theory of human memory. By this theory the human mind is thought to receive and store in the subconscious every bit of data taken in by the senses. Hypnosis is regarded as a legitimate vehicle for tapping the subconscious to retrieve data recorded therein which has proven to be inaccessible to the subject's conscious memory. "The assumption, however, that a process analogous to a multichannel videotape recorder inside the head records all sensory impressions and stores them in their pristine form indefinitely is not consistent with research findings or with current theories of memory." 

Today, thanks to research with fMRIs and other modern neuroscience advancements, we know conclusively that the "videotape recorder" theory is hoakum. It can't even be said to be a disputed question anymore. And that's the main basis upon which proponents rested their arguments for using hypnosis on witnesses.

It's hard to understand how "forensic hypnosis" is still a thing in 2017. Further evidence, if any were needed, that judges in general make rotten forensic gatekeepers. This is just embarrassing.