The researchers explored ex-offenders’ gambling attitudes and behaviour and whether a brief intervention could be useful for those with probable gambling disorder (GD). The researchers recruited 126 people on probation, parole, or supervised release. Participants completed an online survey. The researchers randomly assigned 102 participants with probable GD to either receive a brief intervention plus treatment referral or just referral. Both groups developed more negative attitudes about gambling, spent less money, and gambled less often at one month after the study. This finding suggests that a brief intervention may be useful in reducing criminals’ gambling behaviour. This study has implications for screening and treating gambling problems within the criminal justice system.