Intellectual disability, criminal offending and victimisation

There is considerable evidence that people with intellectual disability (PWID) are at an increased risk of offending and are overrepresented in correctional settings. There is also widespread concern, despite the lack of a robust evidence base, that PWID are more likely to be victims of crime, and that victimisation of PWID is underreported. To date, much of the extant research has employed methodologies that are unable to quantify the risk of both offending and victimisation for PWID compared to the community, and/or use samples inclusive of the Borderline range of intellectual disability (ID). In order to address these concerns, epidemiological research is required, using a population-based, well-defined sample of PWID, and measures of offending and victimisation derived from official criminal records. This research study utilised a large sample of PWID (n=2220) from a database held by the Department of Human Services in Victoria, Australia, and matched these with contact-based records from Victoria Police and the Department of Health to quantify the risk for offending and victimisation, and consider any impact of dual disability on this risk. Data was then compared to a community sample derived from the Australian Electoral Commission (AEC), to determine the differences in risk between PWID and the general population. Results indicated increased risk for offending in PWID when compared to the community sample, particularly for violent and sexual offence types. Results also showed that PWID were less likely to have been a victim of crime overall, but their risk for being a victim of violent or sexual offences was far greater than people without an ID. Dual disability increased risk for offending and victimisation over and above ID; however the nature of this relationship remains complex. This suggests a lack of specialised services necessary to support and protect these individuals. Providing training to employees in justice, health and disability services to identify and treat the mental health issues of PWID may go a long way to redressing the balance.