Alcohol intoxication is a common feature in crime, yet jurors often possess little understanding of how alcohol affects eyewitness memory. Furthermore, jurors are often blind to biases about different crimes that affect their interpretation of eyewitness evidence.Accordingly, the current study investigated the impact of (1) a victim's intoxication status during a crime and (2) the type of crime committed on mock jury decision-making.Undergraduate students (N = 228) read a trial transcript describing a rape or robbery committed against a woman who was either sober or intoxicated to a low, moderate, or severe degree when the crime occurred. They also completed questionnaires assessing trial-related judgements, alcohol beliefs, behaviours and familiarity, and sexist attitudes towards women.Mock jurors incorrectly perceived alcohol as detrimental to the victim's credibility at any dose. However, the victim's intoxication status failed to influence verdict decisions. Verdicts were instead better accounted for by extra-legal factors such as gender, ethnicity, and alcohol-related beliefs. Variance in jury decision-making according to crime type was not observed. These null findings may be the product of methodological constraints rather than genuine non-effects, and thus further research is required. The current study asserts the need for jury education to correct misconceptions about the effects of alcohol on eyewitness memory, and continued exploration of the role of extra-legal factors in intoxication-related cases.

This online survey study explored how Australian laypeople (N = 147) define alcohol intoxication using language, standard drinks, blood alcohol concentration (BAC), and symptoms. Participants used an extensive vocabulary to describe intoxication and better understood intoxication in terms of standard drinks and symptoms compared to BAC. Lay intoxication definitions and perceived alcohol-induced impairment thresholds (memory and capacity for consent) were influenced by individual differences (e.g., age, personal alcohol consumption). Participants rated symptom-based evidence as most useful when evaluating a person’s intoxication status in a legal setting and welcomed expert evidence. Findings can inform litigation and educational strategies that facilitate accurate engagement with alcohol intoxication in the courtroom.