Following the mass shooting at Columbine, the Secret Service and the U.S. Department of Education tried to determine if they could predict such future attacks.
They examined 37 school-targeted attacks, committed by 41 individuals over the span of 25 years from 1974 to 2000. The final result of the study was the Safe School Initiative.
The graphic below details some of the common behavior or characteristics these violent individuals demonstrated before their attacks. Mousing over each colored box provides the study’s finding in each category.