The program is based on research revealing that a small proportion of offenders commit most of the serious and violent juvenile crimes and that specific behavioral pathways and factors contribute to serious, violent, and chronic juvenile crime. These factors include delinquent peer groups, poor school performance, high-crime neighborhoods, weak family attachments, lack of consistent discipline, and physical or sexual abuse. Effective intervention strategies and programs for these delinquents have also been documented. These programs use the social development model to enhance protective factors against delinquent behaviors. Basic principles include strengthening the family, supporting core social institutions, promoting delinquency prevention, intervening immediately and effectively when delinquent behavior occurs, and identifying and controlling the small group of serious juvenile offenders. Figures, table, and appended background information