In cases of school shootings in which people were killed and wounded, school students, teachers, administrators, and even law enforcement officials were exposed to information and events that, if interpreted properly and communicated to key persons, could have resulted in preventive action prior to the first shot being fired. The lack of training and a structured procedure for recognizing and reporting warning signs of a pending violent attack at school by specific individuals contributed to the tragic consequences that ensued. One of the domains where “red flags” have been prominent in past school shootings is overt threats made by the shooters. Perpetrators of past school shootings have made threats on Web sites, in their writings, in videos they have made, in comments to fellow students, and even in the presence of law enforcement officers. Various characteristics of shooters and potential shooters can also be “red flags.” These characteristics include intense and obsessive feelings of being victimized at school and significant changes in the person‘s appearance, social environment, language, dress, habits, emotions, values, and other communication means and styles. Any significant change in what is considered normal behavior for a given individual can be a warning sign of potential violence. Students, teachers, and school administrators should be trained in the importance of these signs and what should be done if they observe or otherwise become aware of them. This implies that a structure be in place that is staffed by trained people who are qualified to analyze the relevance of any information received and make decisions about actions that should be taken based on a risk assessment. 2 figures