Before this Colorado massacre was the Virginia Tech(32 murdered), which is the worst shooting(fatalities & etc) in USA history — before was another Colorado shooting, Columbine High School(13 murdered).
The gunman walked in with a costume on from what witnesses said:
The man was wearing a ballistic helmet and protective gear for his legs, throat and groin, black gloves and a gas mask. Jennifer Seeger, who survived the attack, said she had seen the man and thought his get-up was part of the entertainment for the film’s debut.
James Holmes was a college student at the University of Colorado. Headline News reports that all the guns he had were legally purchased.