The diversity and nature of offending in people with intellectual disability

Dr Margaret Nixon1, Ms Katie Richardson1, Prof Stuart Thomas2, Prof Michael  Daffern1, Prof James Ogloff1

1Centre for Forensic Behavioural Science, Alphington, Australia, 2RMIT, Melbourne, Australia


Our understanding of offending behaviour by people with intellectual disabilities has, to date, struggled to progress beyond reports of prevalence. Unlike mainstream forensic research, studies of this population have remained largely aetheoretical and narrow in scope. The existing literature has a tendency to treat PWID who offend as a homogenous group, with a focus on singular, high impact offences such as arson and sexual assault. This focus has potentially skewed our understanding of the nature of offending in this population, and limited opportunities for more effective treatment and intervention. This data linkage study uses a large Victorian sample of PWID (n=2220), to examine the nature and diversity of offending behaviours. The study identifies factors that may contribute to specialised and diverse offending trajectories, and provides a framework for a broader and more comprehensive understanding of both the range and  nature of offences perpetrated by PWID, and the risk and protective factors that may contribute to offending behaviours. By comparing these factors in PWID with offending histories, and those without, we can determine more appropriate support for PWID in contact with the criminal justice system.


Dr Nixon is a Lecturer at the Centre for Forensic Behavioural Science, Swinburne University of Technology and Forensicare.  Her research interests include intellectual disability and offending behaviour, dual disability, prison based interventions and the intersection between offending and victimisation.