Blue Line

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Memory, recovered memory and false memory in sexual assault and homicide investigations: Part 2

April 13, 2023  By Peter Collins

In the last edition of Blue Line, we discussed the topic of false memories. Memory is malleable; details can be distorted, and wholly false memories can be implanted. Just because a memory report is detailed, confidently expressed and emotional, does not mean that it reflects a true experience.

Research has shown that certain individuals may be more susceptible to false memories, and they can be produced in a laboratory setting.1 The factors that make people more susceptible to imagination inflation are memory problems, difficulties with reality monitoring and the ability to produce vivid imagery. Individuals who are susceptible to false memories may have a “source monitoring deficit” – incorrect judgements about the origin or source of information. A false memory is highly dependent on the individual being able to create or retrieve misinformation.

Case one

Patricia, and her older sister, were sexually assaulted by a friend of the family when they were in elementary school. As an adult, she went to the police to report the abuse. The abuse consisted of several episodes of the family friend rubbing her vagina. On one occasion he allegedly placed her hand on his exposed erect penis. Independently, her older sister confirmed that this same friend of the family, who was now deceased, abused her in a similar manner.

Patricia decided to seek out counselling to address her victimization and entered therapy with a counsellor who was said to be an expert in sexual “ritual” abuse. With the assistance of this “therapist”, Patricia started to recover memories of being a victim of ritual abuse and that her parents were members of a cult. The ritual abuse was said to take place at the cottage of her perpetrator. Patricia started to remember that, in addition to being sexually abused, she was forced to kill same aged friends – and classmates – with a knife, ordered to disembowel animals and was “programmed” to kill herself if she disclosed information about the cult. She stated that these recollections were a result of body memories from before the age of three.


When Patricia returned to the police with this newly remembered information, she truly believed that 21 of her schoolmates and neighbourhood friends had been murdered by the satanic cult involving her parents. During the police investigation, Patricia could only remember the name of one of the 21 victims: Rosemary. Her older sister, who denied any knowledge of a satanic cult, recalled a family trip through the United States, with a visit to their former neighbours—and Rosemary was alive and well. In their thorough investigation, the police could not substantiate any of Patricia’s allegations.

Just because a memory report is detailed, confidently and emotionally expressed, it does not mean that it reflects a true experience.

Case two

In the early 1980s, a teen girl was last seen getting into an older model car. She had been hitchhiking. Three days later her body was discovered in an adjacent jurisdiction, sexually assaulted and murdered. Three decades later, Eddie came forward to the police because he began to recall that not only was he a backseat passenger of the car that picked up the hitchhiker, but he also witnessed her sexual assault and murder. Eddie was six years old at the time and his four-year-old brother was also in the vehicle. Eddie admitted that he had been a problem drinker and these memories started to return after he became sober, and after seeing a former neighbour who, by coincidence, had a previous conviction for sexual assault.

Aided by researching the case – which remains unsolved and an open investigation – and by seeing a religious counsellor, he presented these “facts” to the police who spent 16 months investigating these claims. Eddie even named the perpetrator: his former neighbour. His account was inconsistent with the crime scene findings and the hold-back evidence. Eddie would remember more and more details as time went on. When informed that his claims were unsubstantiated, he went to the local media who eagerly championed his claims and then retained a local psychiatrist who said Eddie was the “real deal”. A Facebook page was created to support his claims and to criticize the investigation.

In May 2016, the police announced that through resubmitting the original DNA from the scene, due to the advancements of the science, the murder was committed by a still unknown male subject, but it was not the individual who Eddie insisted was responsible. The case remains unsolved and still is an active investigation.


Individuals who suddenly remember previously forgotten or “repressed” memories may come to believe these memories to be true. They may be confusing an internally generated thought with a genuine memory. This subtle interaction between intrinsic source monitoring difficulties and suggestive therapeutic techniques can result in the development of false memory.

Every case of a violent crime must be investigated on its own merit but in some cases, just because a memory report is detailed, confidently and emotionally expressed, it does not mean that it reflects a true experience. Details can be distorted and wholly false memories can be implanted.

Many abuse survivors claim that they forgot their abuse for a time, but this does not mean that they repressed their memory of it. Many abuse survivors will not mention their abuse when asked, but this is not proof of repression.

In the Netherlands, many cases involving potential false memories don’t make their way to court. Instead, they are frequently evaluated by the Netherlands Expert Committee for Equivocal Sexual Abuse Allegations. This committee consists of different experts (e.g., investigative psychologists, cognitive psychologists and clinical psychologists) who evaluate potential false memory cases and provide advice to the public prosecutor about whether an investigation should be continued in these cases. Recent data from this committee revealed between 2008 and 2020, 17 per cent (n = 88) of the evaluated cases involved possible false recovered memories.


  1. The Deese-Roediger-McDermott (DRM) Paradigm, the Misinformation – Suggestive Pressure Paradigm and the False Memory Implantation Paradigm.
  2. Loftus, E. & Davis, D. (2006). Recovered memories. Annual Review of Clinical Psychology, 2, 469–498.
  3. Otgaar, H. et al (2022) A court ruled case on therapy-induced false memories. American Journal of Forensic Sciences. DOI: 10.1111/1556-4029.15073
  4. Otgaar, H. et al (2019). The Return of the Repressed: the persistent and problematic claims of long-forgotten trauma. Perspectives on Psychological Science Vol. 14(6) 1072–1095.
  5. Radvansky, G. (2021). Human Memory – 4th edition. New York: Routledge.
  6. Pardilla-Delgado E. & Payne J. (2017) The Deese-Roediger-McDermott (DRM) Task: A Simple Cognitive Paradigm to Investigate False Memories in the Laboratory. J Vis Exp. 2017 Jan 31;(119):54793. doi: 10.3791/54793.

Peter Collins is the operational forensic psychiatrist with the Ontario Provincial Police’s Criminal Behaviour Analysis Section. He is also a member of the crisis/hostage negotiation team of the Toronto Police Service Emergency Task Force. Dr. Collins’ opinions are his own. Contact him at

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