School bullying is associated with school shootings ; the vast majority of students ( 87 % ) believe that shootings occur in direct retaliation to bullying . School shooters who left behind evidence that they were bullied include Eric Harris and Dylan Klebold ( perpetrators of the Columbine High School massacre ) , Charles Andrew Williams , Eric Hainstock , Seung-Hui Cho , Wellington Menezes Oliveira , Kimveer Gill , Karl Pierson , and Jeff Weise
Columbine High School massacre
Columbine High School massacre
School bullying