Investigators found Lanza was fascinated with mass shootings , most notably the Columbine High School massacre and the Northern Illinois University 2008 shooting . Among the clippings found in his room , there was a story from '' The New York Times '' about a man who shot at schoolchildren in 1891 . His computer contained two videos of gunshot suicides , movies that showed school shootings and two pictures of Lanza pointing guns at his own head . It was also claimed that he had edited Wikipedia articles about mass murderers
Columbine High School massacre
Columbine High School massacre
Sandy Hook Elementary School shooting