The vast majority of the nation's students will complete their schooling without ever being touched by peer violence. Nevertheless, recent school attacks carried out by students have shaken the image of schools as reliably safe and secure environments in which the qualifications of teachers and the efficacy of the educational curricula are the most pressing concerns of educators and parents. Televised images of frightened and injured students fleeing school grounds have imprinted themselves on the American consciousness. "Columbine," the Littleton, Colo. high school that on April 20, 1999, was the scene of the most violent of the school attacks recorded to date in the United States, has entered contemporary vocabulary as a national symbol of the violence that claimed the lives of 14 students and a teacher on that day. Incidents of targeted school violence occurred in 37 communities across the country between December 1974 and May 2000. Compared to the other types of violence and crime children face both in and outside of school, school-based attacks are rare. While the Department of Education reports that 60 million children attend the nation's 119,000 schools, available statistics indicate that few of these students will fall prey to serious violence in school settings. However, highly publicized school shootings have created uncertainty about the safety and security of this country's schools and generated fear that an attack might occur in any school, in any community. Increased national attention to the problem of school violence has prompted educators, law enforcement officials, mental health professionals, and parents to press for answers to two central questions: "Could we have known that these attacks were being planned?" and, if so, "What could we have done to prevent these attacks from occurring?" For example, what should happen when a student comes to attention for saying something or behaving in a manner that causes concern, as in the following instances? - "The kids are saying that Johnny told his friends not to go to the cafeteria at noon on Tuesday because something big and bad is going to happen." - Marty, who has appeared withdrawn and irritable the past few weeks, handed in a story about a student putting a bomb in an empty school. - Sandy brought bullets to school to show friends. - Rafael, who got pushed around again after gym class, stormed out in tears, shouting "You're all going to pay!" - Casey, who was suspended last year for bringing a knife to school, left a "hit list" on his desk. - Terry submitted an essay in which an assassin blew up the school, attacked the governor, and then killed himself. Given the enormous concern about targeted school violence, these reported statements and behaviors cannot be ignored. But how should school officials and other responsible adults respond? This publication, Threat Assessment in Schools: A Guide to Managing Threatening Situations and to Creating Safe School Climates, is the product of an ongoing collaboration between the U. S. Secret Service and the U. S. Department of Education to begin to answer these questions. Its focus is on the use of the threat assessment process pioneered by the Secret Service as one component of the Department of Education's efforts to help schools across the nation reduce school violence and create safe climates. As developed by the Secret Service, threat assessment involves efforts to identify, assess, and manage individuals and groups who may pose threats of targeted violence.