Risk Assessment and Management of Group-Based Violence

Group-based violence (GBV) may be defined as actual, attempted, or threatened physical injury that is deliberate and nonconsensual, perpetrated by one or more individuals whose decisions and behaviour are influenced by a group to which they currently belong or with which they are affiliated. Although GBV represents a serious challenge to professionals around the world tasked with protecting public safety, there is lack of systematic, evidence-based procedures to aid decision-making. This dissertation reports the development and evaluation of a new set of structured professional judgment (SPJ) guidelines for assessing and managing GBV, called the Multi-level Guidelines (MLG; Cook, Hart, & Kropp, 2013). The first part of the dissertation describes the development of the MLG based on a Campbell Collaboration review and expert feedback. The MLG was structured according to an ecological model of GBV comprising 20 risk factors in four nested domains: Individual, Individual-Group, Group, and Group-Societal. The second part of the dissertation reports on an evaluation of the MLG in two samples of criminal justice and mental health professionals who completed training and rated case studies. Consistent with predictions, the results of the evaluation indicated that professionals who completed the training: (1) reported significant increases in their confidence, competence, and knowledge concerning the assessment and management of GBV significantly: (2) appraised the MLG to be useful for their practice; and (3) made judgments concerning the presence of risk factors, as well as the nature and level of risks posed, with a degree of reliability comparable to that reported in evaluations of other SPJ guidelines. The professionals also provided feedback for improving the MLG. Overall, the findings suggest the MLG may aid decisions about GBV made by professionals working with diverse problems in a wide range of settings.