Accuracy of evidence from drunk sex assault victims not affected by intoxication – study

The accuracy of evidence given by victims of sexual assault is not affected by alcohol intoxication, according to a British study.

Researchers at the University of Leicester found that participants who were drunk, reported fewer pieces of information about an assault but the information provided was as accurate as that of those who were sober.

Results from the research by the university’s Department of Neuroscience, Psychology and Behaviour are now being applied in Britain in conjunction with the Crown Prosecution Service and Leicestershire police to develop national guidelines about the conduct of police interviews with intoxicated victims of sexual assault.

Eighty eight women aged between 18 and 31 were involved in the study after responding to an advertisement for “female social drinkers”.

According to the researchers the rate of sexual assault on women aged between 16 and 24 is four times higher than on any other age group

The study “Alcohol and remembering a hypothetical sexual assault: Can people who were under the influence of alcohol during the event provide accurate testimony?” was published in the journal Memory.

The research involved a placebo controlled trial to investigate the effects of alcohol on memory.

Drinks were labelled either “vodka and tonic” or “tonic water” and participants were not told the amount of alcohol they received.

A hypothetical rape scenario was described and participants read introductory information about the male portrayed including a physical description and photograph, and details about his occupation and possessions.

Participants were then presented with 24 sentences which appeared one at a time on a computer screen and they responded each based on whether or not they wished to remain in the hypothetical encounter.

The research team examined the influence of alcohol on remembering the interactive hypothetical sexual assault scenario in a laboratory setting.

All the participants completed an online memory test 24 hours later and four months later 73 per cent completed a recognition test.

Sober participants

The study indicated that participants reported less information if they were “under the influence” compared to women who were not.

But researchers found the accuracy of information from those who had been drinking did not differ from that of sober participants.

Study leader Dr Heather Flowe said "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.”

Dr Flowe said a crime was unlikely to be solved without victim testimony.

“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.”

The study was funded by Britain’s Economic and Social Research Council.