Many perpetrators of mass shootings played violent video games. The teenage shooters in the 1999 Columbine High School massacre of 13 students played violent combat games. [43] Many mass shootings have been carried out by avid video game players: James Holmes in the Aurora, Colorado movie theater shooting (2012); Jared Lee Loughner in the Arizona shooting that injured Rep. Gabby Giffords and killed six others (2011); and Anders Breivik, who killed 77 people in Norway (2011) and admitted to using the game Modern Warfare 2 for training. [53] An FBI school shooter threat assessment stated that a student who makes threats of violence should be considered more credible if he or she also spends "inordinate amounts of time playing video games with violent themes.