Officials also linked violent video games to Lanza's deadly actions. Evidence suggests that Lanza's shooting spree was an attempt to reenact the vision of a video game in real life. A lieutenant on the Connecticut State Police force dismissed this investigation, saying it is just speculation because the shooter is dead. Detectives and government officials are looking very closely at the whole case, however, and a report is expected to appear this summer.
Breivik, the Norwegian shooter, believed himself to be an ultranationalist who killed to fight multiculturalism. Before shooting 69 people at a youth camp, Breivik detonated a bomb outside the prime minister's office. Breivik was judged to be sane, and sentenced to 21 years in prison.
http://www.cnn.com/2013/02/19/justice/connecticut-newtown-shooting/index.html?hpt=ju_c2