Data from a longitudinal study of 294 African American and Latino adolescent boys and their caregivers living in poor urban communities were used to test a developmental-ecological model of violence. Six annual waves of data were applied to evaluate the relations between microsystem influences of parenting and peer deviance (peer violence and gang membership), macrosystem influences of community structural characteristics and neighborhood social organization, and individual involvement in violence (level and growth). Structural equation modeling analyses showed that community structural characteristics significantly predicted neighborhood social processes. Parenting practices partially mediated the relation between neighborhood social processes and gang membership. Parenting practices was fully mediated in its relation to peer violence by gang membership. Gang membership was partially mediated by peer violence level in its relation to individual violence level. Although the overall set of relations does not satisfy mediation requirements fully in all instances, the model was validated for the most part, supporting a focus on a multilevel ecological model of influences on risk development.