Some Warning Behaviors Discriminate Between School Shooters and Other Students of Concern

A typology of 8 warning behaviors for targeted violence— dynamic and superordinate patterns which may indicate accelerating risk of violence—were tested in a small sample of German school shooters (n 9) and students of concern (n 31) to see if any warning behaviors would be significantly different between the groups. Five warning behaviors were found to occur with significantly greater frequency in the school shooters and discriminate between the samples: pathway, fixation, identification, novel aggression, and last resort. All effect sizes were large ( .50). The findings are discussed in the context of school-shooting data from Germany and the United States and their implications for threat assessment.