K-12, college/university, and mass shootings: similarities and differences.

In a 2003 study, we examined five antecedents of school shootings - a history of rejection, acute rejection experience, history of psychological problems, fascination with death or violence, and fascination with guns. In three studies, the current project examined the role of these factors in 57 K-12 shootings, 24 college/university shootings, and 77 mass shootings that occurred since the original study. Over half of all shooters had a history of psychological problems.