School shooters use violent phantasies to compensate for psychosocial injuries, a perceived lack of reference figures and missing viable perspectives in their social reality. These phantasies intensify over years and become more detailed as the shooting draws closer. As the mental images become more specific, shooters often become buttressed by a distorted sense of what is just or moral, such as the need to avenge a perceived offense or the belief in a divine right to decide the fate of others. In their personal view, school shootings appear as means to gain control, a sense of masculinity, and recognition. Although they may at first hide their destructive phantasies out of fear of rejection, they increasingly feel a need to express them. They begin to leak their thoughts and plans to friends, chat rooms, and even media outlets. Distinguishing extreme violent phantasies from harmless daydreaming can enable parents, teachers, social workers, and other trusted adults to intervene months before a school shooting. These adolescents need help to build protective factors: social prospects, a pro-social self-image, and strong relationships with peers, teachers, and other adults. Strong pro-social relationships enable them to find a sense of bonding with society and also help them to find solutions for seemingly insoluble problems and to reduce their subjective need for violent compensatory phantasies.