"In 2014, the U.S. Department of Justice, Office of Community Oriented Policing Services (COPS Office) and the National Institute of Justice (NIJ) provided funding to the Police Foundation to initiate the Averted School Violence (ASV) project. Through this project, the Police Foundation developed a database (Police Foundation 2018) to collect, analyze, and publish (in an online library [Police Foundation 2018b]) incidents of averted and completed acts of school violence that have occurred since the attack on Columbine High School in Littleton, Colorado, on April 20, 1999. The data are drawn from the public domain as well as from law enforcement, school officials, and others entering reports into the database. The database is intended to serve as a resource to law enforcement, schools, mental health professionals, and others involved in preventing school violence by sharing ways in which other school attacks across the country have been identified and prevented. In this report, 51 completed and 51 averted incidents of school violence, drawn from the ASV database, were analyzed to help further our understanding of averted and completed school attacks. The report also seeks to provide important lessons about how school violence can be prevented."--Page 1.