That's right, intoxicated eyewitnesses are just as reliable as ones who are sober as a church mouse.
In arriving at this ground-breaking conclusion, researchers in Sweden -- oh, those crazy Swedish scientists -- served screwdrivers to two groups of no-doubt willing volunteers. One group had enough vodka in their OJ to reach a .04 blood alcohol concentration, the other 07. Then the participants, along with an alcohol-free control group, were shown a five-minute video of man kidnapping two women at a bus stop. Close-up views of the man's face was shown for 31 seconds during the film.
A week later the volunteers were invited back and asked to pick the kidnappers out of a lineup. And here's what happened, as reported in Research Digest ...
A week later, the participants were invited back and completed a surprise identification task. In a sober state, they saw an 8-man line-up on a computer screen that either did, or did not, feature the kidnapper who they'd seen in the film. The test administrator didn't know which condition participants were in, nor whether the culprit was present. Each participant had to say whether the culprit was in the line-up, answering either "yes", "no the culprit is not present" or "do not remember.
Amazingly, the participants with the highest blood alcohol level actually scored higher than either of the other two groups (though not significantly).
Still, none of the scores were particularly good; even the best group was only slightly better than chance.
The reason for the study is that, as police know well, it is very common for witnesses to crimes to be intoxicated, and there's been scant research on how alcohol affects eyewitness performance.