This proposal rests on recognition that adolescents and young adults in the United States are at high risk for interpersonal violence. The risk is particularly high for black youths. The proposed approach focuses on St. Louis and uses multiple methods in multiple settings. It involves coordinated responses from many groups and organizations, directed at specific risk groups, with social supports for individual change. Its behavioral change objectives are to reduce injuries and deaths from assaults, to reduce the availability of guns and other weapons, and to reduce the overall level of assaultive violence in the target group. The basic intervention agent is the Assault Crisis Team, a group of 8-10 trained violence prevention specialists. Each team will be composed of medical, social service, educational, and criminal justice professionals, as well as community residents who have received training in violence intervention skills. The teams will operate in four settings: an emergency room that treats persons at high risk for violence, a juvenile detention center, an adult jail, and a high-risk neighborhood. The project outcomes would be evaluated at both the individual and aggregate levels. Tables and 73 references