The witness wore beer goggles

Research suggests those viewing a crime can protect a memory of an incident by drinking alcohol. Police Professional looks at how people’s recollection can be altered by moderate drinking. According to the most recent Crime Survey of England and Wales, 53 per cent of all violent incidents are alcohol-related and most occur in pubs, clubs or bars where witnesses – and offenders – are likely to be under the influence. Given how common it is for witnesses to crimes to be intoxicated, there has been surprisingly little research on how alcohol affects eyewitness performance. Common sense suggests that ‘drunk’ witnesses will be less reliable than sober ones, but new research has found that this is not always the case, and in some circumstances alcohol can actually improve eyewitness recall. A study led by Julie Gawrylowicz, a lecturer in psychology at Glasgow Caledonian University, together with Anne Ridley and Ian Albery of London South Bank University, and published in the journal Psychopharmacology, shows that if alcohol is consumed after witnessing a crime it can ‘protect’ the memory from misleading information. Eighty-three participants in the study watched a four-minute video depicting a staged distraction burglary in a house. After watching the film, they were split into three groups. The first group was given alcohol. The second group was told they would be drinking non-alcoholic beer, but were in fact also given alcohol. This was to ensure that, as far as possible, it was the effect of the alcohol itself and not expectations about the effect of alcohol that would cause any effects. The third group did not drink at all. On average, participants did not exceed the current drink-drive limit of 80mg of alcohol per 100ml of blood. All participants were then given fake information about the crime video. For example, it was suggested that the victim’s jumper was green instead of blue, and that the thief’s hair was brown instead of black. The following day, they returned when sober and their memory about the crime was tested. “Contrary to the general belief and empirical finding that alcohol impairs eyewitness memory, we found that individuals who consumed alcohol (alcohol and reverse placebo group) after the observed event, but prior to encountering misleading information, reported significantly fewer misinformation items on a subsequent memory test compared to the control group (which did not receive any alcohol),” wrote the authors of the report. “We think this is because alcohol blocks new incoming information, including misinformation, so it is less likely to have a negative impact on what was witnessed. Worryingly, not only were our sober witnesses more suggestible to misinformation than our alcohol consumers, but, when they were asked, they also expressed greater willingness to testify these incorrect responses in a court of law. “Our research challenges the intuitive view that alcohol is bad for eyewitness memory recall by showing that, in fact, it can be the timing of alcohol consumption that is important when it comes to determining how accurate and reliable inebriated witnesses are.” Earlier studies support this. Research conducted by Angelica Hagsand of the University of Gothenburg, Sweden, in 2013 found drunk witnesses performed just as reliably as sober witnesses at recognising a criminal in a line-up. In that study, 123 students were split into three groups. The first group drank orange juice for 15 minutes; the second spent the same time drinking enough orange juice mixed with vodka to reach a blood alcohol concentration (BAC) level of 0.04 per cent; and the final group drank enough vodka and orange to reach a BAC level of 0.07 per cent – just below the legal drink-drive limit in the UK and US, and approximately equivalent to an average-sized man drinking two or three shots of vodka in that time. Five minutes after they had finished drinking, the participants watched a five-minute video of a man kidnapping two women at a bus stop, filmed from the perspective of