This document reports on a systematic review that assessed the effectiveness of interventions with adult male violent offenders, conducted by Cambridge University researchers between January and June 2006.
This report presents the results of a systematic review of research to assess the effectiveness of interventions with adult male violent offenders, conducted in the U.K. and internationally between January and June 2006. The goals of the research review were: to assess the evidence on the effectiveness of interventions with adult male violent offenders; to identify the potential mediators and moderators of the relationship identified in the first goal; and to make recommendations about future research. The authors excluded domestic violence, sexual offending, and offending by persons with a personality or a mental disorder. Key findings suggested that interventions with violent offenders were effective both at reducing general and violent re-offending, with a difference in percentage reconvicted of about eight to eleven percent for general re-offending measures and seven to eight percent for violent re-offending measures; violent offenders had extensive criminal histories and were more likely to re-offend than general offenders, and tended to be more difficult to engage in treatment; and interventions which addressed cognitive skills, anger control, used role play and relapse prevention, and had offenders complete homework, were more effective than interventions that did not. The authors also noted that the effectiveness of interventions varied depending on the features of the study, the content and delivery of the intervention, and the methodology of the study. A limitation reported by the authors was that only a total of 11 reports could be analyzed due to the quality requirements for inclusion in the meta-analysis, which restricts ability to generalize results.