Violence risk assessment: the use of the PCL-SV, HCR-20, and VRAG to predict violence in mentally disordered offenders discharged from a medium secure unit in Scotland

Abstract

Risk assessment tools are increasingly used in the management of mentally disordered offenders in Scotland, but there has been limited research into their validity among this population. The aim of this study was to examine the validity of risk assessment tools in predicting violence following discharge from a Scottish medium secure unit. The PCL-SV, the VRAG, and the historical subset of the HCR-20 were completed on 96 patients. Follow-up information regarding post-discharge violence and clinical factors was collected for two years. Four (4.2%) patients from the sample committed five serious violent offences, while 38 (40.6%) patients committed more than 100 minor violent offences. The risk assessment tools were found to have moderate predictive accuracy for violent outcomes. Thus this study provides useful evidence supporting the validity of risk assessment tools in Scotland. Individual clinical factors such as substance abuse, personality disorder, treatment non-compliance, and symptom relapse are also relevant in risk assessment and management.