False Memories in Historical Sexual Allegations: What the Science Says and How Courts Deal With It

Historical sexual offence allegations often depend almost entirely on memory: what someone recalls about events that may have happened 10, 20 or 40 years ago. Memory research shows that recollections can change over time, and that a person can sincerely remember something that did not happen as they recall it. This guide explains what the science says, how it arises in court, and how a defence approaches it.

How memory works

Memory is not a recording that can be replayed. Each time a memory is recalled, it is reconstructed, and it can be influenced by later information, conversations, expectations and emotions. Psychologists have shown in controlled studies that people can come to remember details, and sometimes whole events, that did not occur, and can be confident in those memories.

In 2023 the Psychology and Law Sections of the British Academy published Legal aspects of memory, a summary of the scientific evidence for legal professionals, which the British Psychological Society has endorsed. It covers topics including the effects of suggestion and misinformation, the effect of trauma on recall and childhood amnesia. A widely accepted finding in this research is that the confidence with which a memory is held does not, on its own, show that it is accurate.

False memory, mistake and fabrication

It helps to separate three different things:

• Mistaken detail: the core event may have happened, but dates, places, people present or the sequence of events are wrong. This is very common after a long delay.
• False or contaminated memory: the person genuinely believes in a memory of an event that did not happen, or did not happen in the way they recall, often because of outside influence.
• Fabrication: a deliberately false account.

These are very different defences, and choosing the right one matters. Our guide to defending false allegations covers cases where fabrication is alleged.

How memories can be influenced

Factors that research and case experience suggest can affect memory include:

• Suggestive questioning, whether by family, friends, professionals or investigators, especially leading or repeated questions.
• Therapeutic techniques aimed at recovering memories, such as hypnosis or guided imagery, which professional bodies have warned can create or distort memories.
• Media coverage and online material about similar allegations or about the accused.
• Discussion between complainants, which can lead to accounts becoming more alike over time, whether innocently or not.
• The passage of time, with gaps filled in by what seems likely rather than what is actually remembered.

How the courts deal with memory and delay

In England and Wales there is no time limit for prosecuting serious sexual offences, and juries regularly convict on the basis of historical allegations. The courts deal with the risks of delay in several ways:

• Jury directions on delay: the judge should explain to the jury the difficulties that delay can cause, including the defendant's difficulty in answering the allegation and the loss of records and witnesses.
• Directions on avoiding assumptions: judges also warn juries against assuming that a late complaint must be untrue, because there are many reasons people do not report straight away.
• Abuse of process: in rare cases a prosecution can be stopped if delay makes a fair trial impossible.
• Expert evidence: admitted only where it deals with matters outside a jury's ordinary experience, which may include recovered memories or suggestive influences.

Offences are charged under the law in force at the time, which for allegations before May 2004 usually means the Sexual Offences Act 1956. See our guide to historical sexual offence allegations.

How the defence tests memory evidence

Rather than simply disputing the account, a strong defence usually builds an evidential picture:

• Tracing how the account developed: the first disclosure, to whom and in what words, and how the account has changed through later statements and the video-recorded interview.
• Testing details against records: school, medical, employment, housing and travel records, photographs and diaries can show whether places, people and dates fit.
• Investigating outside influences: therapy, contact with other complainants, media coverage, social media groups or civil compensation claims.
• Disclosure: pressing the prosecution to obtain and review relevant third-party material, such as social services and counselling records, and applying to the court where necessary.
• Expert input: in suitable cases, a report from a memory expert to assess whether the account shows features associated with contamination or reconstruction.

Lessons from past investigations

High-profile failures have shown the risks of investigators accepting accounts without testing them. Sir Richard Henriques's independent review of the Metropolitan Police's Operation Midland, carried out in 2016 and published more fully in 2019, identified serious failings, including a failure to test the complainant's account properly. The complainant in that case was later convicted of perverting the course of justice. That case involved deliberate lies rather than false memory, but it shows why careful testing of every account matters.

What to do if you face a historical allegation

• Do not attend a police interview without a solicitor. Advice at the police station is free.
• Start gathering documents from the relevant period, such as addresses, jobs, diaries and photographs, and give them to your solicitor rather than the police.
• Do not contact the complainant or anyone you think may be a witness about the allegation.

See our guide to police interviews, and our pages on being released under investigation and sexual offences involving children, which many historical cases involve.

Frequently asked questions

This article is general information about the law in England and Wales, not legal advice.