The problem of violence in schools has not gone away despite radical reductions in violent crimes throughout the country over the last decade. Students continue to harrass, haze, and harm each other in a variety of ways, disrupting classrooms and whole schools. In the wake of the Columbine massacre, many focused on the worst kind of school violence: deadly assaults with dangerous weapons. But other forms of violence are more persistent, common, and just as destructive in many ways: fighting, sexual abuse, carrying weapons to school, vandalism, and assorted other crimes that happen behind the closed doors of elementary, middle, and high schools across the country. The consequences range from violent victimization and death, to the disruption of learning and fear among student bodies and teaching staffs. Here, Thomas provides a foundation for understanding why the violence occurs, preventing it from happening, and treating both offenders and victims after it happens.