The Unreliability of Confessions: Implanted Memories

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Police confessions

For many, a confession is indisputable evidence of a person’s guilt.

However, a significant body of scientific research has found that people can easily be persuaded to confess to serious crimes that they did not commit.

Wrongful convictions

In 2014, a team of lawyers and statisticians asserted that 14.1% of people who were sentenced to death in the US were falsely convicted.

In a nation with over 2 million behind bars, a comparable rate of false convictions for non-capital punishments would amount to tens of thousands of innocent lives ruined.

The National Registry of Exonerations cites 1,625 exonerations since 1989. The average prison time served for these people was more than nine years.

Almost 20 percent of exonerations in 2015 were for convictions based on false confessions. Those cases were mainly for homicides involving defendants under the age of 18 and intellectually disabled persons.

In a separate analysis by the Innocence Project of hundreds of cases since 1989, false confessions were found to be the leading cause of wrongful convictions. Overall, about 31 percent of wrongful convictions included a false confession. For homicides, that number ballooned to 63 percent.

Confession in three hours

Research undertaken by Julia Shaw from the University of Bedfordshire found that a ‘false memory’ is relatively easy to implant.

“Our findings show that false memories of committing crime with police contact can be surprisingly easy to generate, and can have all the same kinds of complex details as real memories,” Shaw’s research found.

“All participants need to generate a richly detailed false memory is three hours in a friendly interview environment, where the interviewer introduces a few wrong details and uses poor memory-retrieval techniques.”

The research found that the person’s belief in this false memory can be overwhelming and the details intricate, so much so that the person maintains that belief well into the future.

The study

Ms Shaw and her colleague, forensic psychologist Stephen Porter from the University of British Columbia in Canada, recruited 60 university test students who had never been involved in a crime.

These students underwent three 40-minute interviews over a three-week period. Unknown to them, the researchers asked their primary caregivers to fill out a questionnaire about the experience of the students when they were aged 11 to 14.

During the first interview, researchers outlined two incidents that had actually occurred during the interviewee’s life, plus at least ‘false event’.

Half of these false events involved a serious crime. The other half involved another traumatic event which did not involve a crime, such as being injured or losing a lot of money. For these false events, students were encouraged to ‘remember’ as much as they could.


The study found that 71% of the students developed a ‘memory’ of the ‘false crime’ and 76.6% of developed a memory of the ‘false traumatic event’.

“We suspect that if we added more interviews, we kept going, we may have gotten close to 100 per cent,” Stephen Porter remarked, adding that the methods employed during the study were similar to those used by police – including asking leading questions and suggesting there was evidence linking them to the incident.

“Inherently fallible and reconstructive memory processes can quite readily generate false recollections with astonishing realism,” Shaw stated. “This research speaks to the distinct possibility that most of us are likely able to generate rich false memories of emotional and criminal events.”

Despite the memories being verifiably false, the students created extremely vivid false stories, and were confident of their truth.

Criminal law

The unreliability of confessions has led to changes in police practices and the laws of evidence.

Part 3.4 of the Evidence Act 1995 imposes restrictions on the use of ‘admissions’, and section 165 categorises admissions as ‘unreliable evidence’ which requires judges to:

  • Warn the jury that the evidence may be unreliable, and
  • Inform the jury of matters that may cause it to be unreliable, and
  • Warn the jury of the need for caution in determining whether to accept the evidence and the weight to be given to it.

The research of Shaw and Porter adds to a large body of evidence which suggests that confessions are indeed far from reliable.

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Zeb Holmes

Zeb Holmes

Zeb Holmes is a lawyer with a passion for social justice who advocates criminal law reform, and a member of the content team at Sydney Criminal Lawyers®.

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