Some reluctance exists among disability staff to report to police potentially criminal behaviour by people with intellectual disabilities. Both the nature and frequency of these behaviours and decision-making processes of staff concerning police involvement remain poorly understood. This study sought to explore potentially criminal behaviour by people living in disability services and the frequency of police involvement. A broad spectrum of potentially criminal behaviours was reported, most frequently involving acts of physical aggression. Police were contacted in 101/370 (27%) of the incidents reported; two-thirds involved acts where there was an identifiable victim; incidents reported to police were most likely to occur outside the disability service. A more detailed understanding of disability staff decision-making as it relates to initiating contact with the police, and the immediate and long-term issues and benefits concerning police contact and intervention, is required so as to more effectively prevent and manage potentially criminal behaviour.