To identify any differences between patients referred by police compared with patients referred from other sources, to a psychiatric hospital in Australia, a retrospective audit of 200 patient files was undertaken. The two most common reasons for the involuntary referral of patients by police were bizarre ideas (33%) and threats of suicide (28%). When 101 patients referred by police were compared with 99 patients from other sources, police referrals were three times more likely to be diagnosed with a mental and behavioural disorder because of psychoactive substance use, less likely to be diagnosed with a mood disorder, and less likely to be diagnosed as psychotic. Police referrals were more likely to have worse functional scores; exhibit aggressive behaviour; spend fewer days in hospital; more likely to be admitted to the psychiatric intensive care unit, and to be secluded. The most important predictor for a police referral was drug or alcohol problems. The study indicates that patients referred by the police were more likely to demonstrate particular characteristics compared with patients referred by other sources.