Two-Tiered Violence Risk Estimates: A Validation Study of an Integrated-Actuarial Risk Assessment Instrument

This study is an initial validation study of the Two-Tiered Violence Risk Estimates instrument (TTV), a violence risk appraisal instrument designed to support an integrated-actuarial approach to violence risk assessment. The TTV was scored retrospectively from file information on a sample of violent offenders. Construct validity was examined by comparing the TTV with instruments that have shown utility to predict violence that were prospectively scored: The Historical-Clinical-Risk Management-20 (HCR-20) and Lifestyle Criminality Screening Form (LCSF). Predictive validity was examined through a long-term follow-up of 12.4 years with a sample of 78 incarcerated offenders. Results show the TTV to be highly correlated with the HCR-20 and LCSF. The base rate for violence over the follow-up period was 47.4%, and the TTV was equally predictive of violent recidivism relative to the HCR-20 and LCSF. Discussion centers on the advantages of an integrated-actuarial approach to the assessment of violence risk.