The use of structured risk assessment instruments in offenders with intellectual disabilities: A field validity study

The current dominant paradigm for offender rehabilitation is the Risk Need Responsivity (RNR) model. This model states that the treatment of offenders is based on the (baseline) recidivism risk of the offender (Risk), tackles dynamic criminogenic needs (Need) and takes into account responsivity issues (Responsivity). Following these principles, risk assessment is of particular relevance, both in determining the baseline risk level and dynamic risk factors. Risk assessment studies in “mainstream” offender populations are widespread, but this is not the case for offenders with intellectual disabilities (OIDs). Two recent reviews suggest that “mainstream” instruments, developed in non-ID offender samples, have equal validity in OIDs. However, the presence of an intellectual disability is an important responsivity factor. Therefore, it seems appropriate to include unique characteristics of OIDs and their environment, which are addressed in ID-specific tools. Evidence regarding the added value and validity of these tools is however perhaps even more preliminar. This doctoral study aims to contribute to the field by validating several risk assessment instruments in this particular population. It does so by focusing on both static (risk principle) and dynamic risk factors (need principle).