Abstract
Despite the development of programmes to address sexual offending behaviour in offenders with cognitive and social functioning deficits, there is a lack of available psychometric tools specifically designed for this group (W. R. Lindsay, Journal of Intellectual Disability Research, 46, 74–85, 2002). This study firstly examines the psychometric properties of six assessment measures, which were specifically adapted for the lower functioning offender from existing sexual offender assessments. A group of 211 men who had undertaken HM Prison Service's Adapted Sex Offender Treatment Programme (ASOTP) were used in this study. The assessments were found to have reasonable psychometric properties as determined by internal consistency and factor analyses. The second part of the study was an exploration of treatment change. Significant pre- to post-treatment change was found on five of the measures. However, the lack of a comparison group makes it difficult to draw firm conclusions about treatment change. Further evidence is also required to determine the link between self-report assessments and recidivism.