Estimating the risk of crime and victimisation in people with intellectual disability: a data-linkage study

Purpose: People with intellectual disability (PWID) appear more likely to be victims and perpetrators of crime. However, extant evidence pertaining to these risks is limited by methodological weaknesses and the absence of consistent operational definitions. This research aimed to estimate the prevalence of criminal histories and victimisation using a large, well-defined sample of PWID. Methods: A case-linkage study was conducted comprising 2220 PWID registered with disability services in Victoria, Australia, whose personal details were linked with a state-wide police database. Criminal charges and reports of victimisation were compared to a non-disabled community comparison sample (n = 2085). Results: PWID were at increased risk of having a history of criminal charges, particularly for violent and sexual offences. Although the non-disabled comparison group had a greater risk of criminal victimisation overall, PWID had a greatly increased risk of sexual and violent crime victimisation. Conclusions: PWID are at increased risk of victimisation and perpetration of violent and sexual crimes. Risk of sex offending and victimisation is particularly elevated, and signalling the need for specialised interventions to prevent offending and to ensure victims is assisted with access to justice, support, and treatment