Strong associations exist between alcohol consumption and crime, but the extent to which these associations are causal is unclear. One hypothesised explanation is that the pharmacological effects of alcohol reduce cognitive capacity, and risk perception leading to an increased risk of committing a crime while under the influence of alcohol. We propose to examine the extent to which associations detected are causal using data collected at the ALSPAC focus clinic at age 24 years on committing crime while sober (which cannot be due to the situational effects of intoxication) and while under the influence of alcohol. We will examine the effects of alcohol consumption (prevalence, frequency, quantity) on violent and nonviolent crime, compare the association between drinking and engaging in crime while sober to the association between drinking and crime, and investigate whether cognitive factors (such as impulsivity, poor working memory and poor emotion recognition) increase the risk of crime while under the influence of alcohol.