The Virginia Student Threat Assessment Guidelines were developed to help multidisciplinary school-based teams use a decision tree to evaluate student threats and take appropriate preventive action. A main goal of this approach is to allow school-based teams to recognize and respond to the developmental complexities of children and adolescents without resorting to the use of zero tolerance discipline. The model takes a triage approach that involves progressively more extensive assessment and intervention according to the severity of the threat and the student's intentions. The article summarizes two field test studies of the model, a study of training effects on staff attitudes and knowledge about violence prevention, and a quasi-experimental study showing that secondary schools using the model enjoyed a more positive school climate characterized by less bullying and greater willingness among students to seek help for threats of violence. (Contains 1 figure and 22 notes.)