Predicting and understanding risk of re-offending: the Prisoner Cohort Study

• Risk assessment and risk management are key components of the Government’s proposals to detain and treat individuals with Dangerous and Severe Personality Disorder (DSPD). Accuracy in risk assessment plays a major role in identifi cation of the small group of individuals thought to pose a very high risk of harm to society and in monitoring their level of risk during and after treatment (Douglas et al., 2005). The Prisoner Cohort Study was a research project originally commissioned by the Home Offi ce as part of the DSPD programme to evaluate the predictive accuracy of a range of currently available risk assessment instruments for future violent and sexual reoffending. The main aims of the study were to test the accuracy in a UK population of the risk assessment devices and instruments currently being piloted for use in the DSPD centres in predicting serious re-offending, and to identify the best instruments in terms of their accuracy in prediction. Most risk assessment instruments included in this study were previously validated on US/Canadian male prisoners or forensic patients without further differentiation. The study also examined the prevalence of offenders potentially classifi able as having DSPD on the basis of the currently available risk instruments and personality assessments, and their dangerousness in terms of reoffending after release into the community. This report focuses on male offenders and violent re-offending. Data collection for sexual re-offending and for female offenders was ongoing at the time of the preparation of this report. Findings are therefore presented for men serving determinate sentences for violent or sexual index offences interviewed in the fi rst phase of the study (N=1396). Research Summary 6