Juvenile offending and anti-social behaviour are enormous societal concerns. This broad-reaching volume summarizes the current evidence on prevention, diversion, causes, and rates of delinquency, as well as assessment of risk and intervention needs. A distinguished cast of contributors from law, psychology, and psychiatry describe what we know about interventions in school, community, and residential contexts, focusing particularly on interventions that are risk reducing and cost effective. Equally important, each chapter comments on what is not well supported through research, distinguishing aspects of current practice that are likely to be effective from those that are not and mapping new directions for research, policy, and practice. Finally, the volume provides a description of a model curriculum for training legal and mental health professionals on conducting relevant assessments of adolescents for the courts.