The first common theme of this volume is that youth violent behavior is complex and there are multiple etiological pathways to delinquent and violent behavior. It is important to approach the problem from multiple perspectives and disciplines because it stems from multiple sources of risk, including neurobiological, individual, family, neighborhood, ecological and social factors. Violence occurs along a developmental continuum, from aggression and conflict to exposure and victimization from violence, to the lethal perpetration of violence. An integrated, systematic, long-term approach that includes multiple disciplines and intercedes at multiple levels is a necessary strategy for sustainable and generalizable change. Implications for prevention include recognizing that violence is learned behavior, that aggression is stable and chronic, that prevention must be multilevel and multifaceted, and that prevention and intervention efforts need to be systematic and long-term. The chapter recommends that communities, States, and the Nation formulate and implement youth policy that is integrated and coherent, policy that includes strengthening support for families, strengthening efforts to control youth access to firearms, increasing efforts to prevent youth from joining gangs, and assisting those who wish to desist from gang involvement. References