Research suggests that there is no single factor at the root of violence in schools. Rather, it suggests that there are multiple, potentially compounding factors at play. This Report to Congress describes a framework that the National Institute of Justice (NIJ) developed to address the many manifestations of violence in schools. The framework has three major components: physical safety, school climate, and student behavior. The framework aligns with the other school safety frameworks found in the research literature and the findings to date from NIJ's Comprehensive School Safety Initiative, which funded 100 projects in K-12 schools aimed at preventing school violence.