Accuracy of sexual assault testimonies not affected by alcohol intoxication, study finds
People are often concerned about the accuracy of testimony given by victims who were intoxicated during a sexual assault– but a new study by University of Leicester researchers has found that while alcohol intoxicated participants report fewer pieces of information about an assault, the information that they do provide is just as accurate as sober participants.
The research suggests that victims of sexual assault who were intoxicated during the crime can still report accurate information when interviewed by the police despite being intoxicated at the time of the offense.
The paper entitled 'Alcohol and remembering a hypothetical sexual assault: Can people who were under the influence of alcohol during the event provide accurate testimony?', published in the journal Memory, is one of the first studies to use a placebo controlled trial that investigates the effects of alcohol on memory within the context of sexual assault.
The team examined the influence of alcohol on remembering an interactive hypothetical sexual assault scenario in a laboratory setting using a balanced placebo design.
Female participants completed a memory test 24 hours and four months later.
Participants reported less information - by responding 'don't know' more often to questions - if they were under the influence of alcohol during the scenario than those who were not.
However, the accuracy of the information intoxicated participants reported did not differ compared to sober participants, suggesting intoxicated participants could accurately retain information from the event as well as those who were sober.
Dr Heather Flowe from the University of Leicester's Department of Neuroscience, Psychology and Behaviour who led the project said: "Serious violent offenses often involve intoxicated witnesses and victims. In particular, in sexual assault and rape cases, victims and perpetrators are likely to have been under the influence of alcohol during the crime.
"When a victim is intoxicated during the crime, questions about the accuracy of testimony are raised in the minds of criminal investigators. Out of these concerns, the police might forgo interviewing victims who were intoxicated during the offence. On the other hand, almost always in sexual offences, the victim is the only one who can provide information about the crime to investigators.
"Consequently, it is not likely that a crime will be solved without victim testimony. Bearing this in mind, we wondered whether intoxicated victims take their mental state during the crime into account when rendering their testimony to investigators. If they take into account that their memory has been impaired by alcohol, they should report information only when they believe it is likely to be accurate.
"Accordingly, intoxicated victims should report less information overall, but the accuracy of the information they do report might not be different from sober victims."
Together with the Crown Prosecution Service and Leicestershire Police, the research findings are being applied to develop National Guidelines regarding how the police should interview sexual assault victims who were intoxicated during the crime.
Detective Inspector Reme Gibson from Leicestershire Police's Rape Investigation Unit said: "Working alongside the University has been of huge benefit to our understanding of the effects alcohol has on memory.
"It has been a long held misconception that victims and witnesses who are intoxicated are not able to give as good an account as they would when they are sober. The delays in speaking with victims accounts sometimes for loss of potential evidence, although alcohol is not the only factor that would influence whether or not an Officer would interview a victim.
"I hope these findings better support future investigations, particularly in the sexual violence arena which is already often complex and not without challenges."
The team working on the guidelines also includes University of Leicester researchers Dr Anna Carline (School of Law), Dr Clare Gunby (Department of Criminology), Professor Graham Davies (School of Psychology), Professor Mandy Burton (School of Law), and Professor Vanessa Munro (School of Law).
The British Academy and Leverhulme Trust have funded a series of workshops to develop the National Guidelines.
Dr Flowe added: "It's fantastic to see the University of Leicester and the Police leading on this important topic. We are working to improve the quality of how testimony is gathered from victims."
More information: "Alcohol and remembering a hypothetical sexual assault: Can people who were under the influence of alcohol during the event provide accurate testimony?" DOI: 10.1080/09658211.2015.1064536