AURORA, Colorado - US President Barack Obama will visit Colorado on Sunday to meet victims of the Batman cinema massacre, a day after police entered the gunman’s booby-trapped apartment. The visit also comes after police revealed the names of the 12 people who died — including a six-year-old girl whose mother was seriously injured — while asserting that the alleged killer had been planning the attack for months. The White House said Obama would meet with families of the victims and local officials in Aurora, near Denver where James Holmes, 24, is said to have opened fire during a packed midnight screening of “The Dark Knight Rises.”

The actor who plays the caped crusader in the film, the last in the Batman trilogy, voiced sorrow at the shooting, and the studio behind the movie said it was withholding box office data out of respect for the victims. “Words cannot express the horror that I feel,” British actor Christian Bale said in a statement. “I cannot begin to truly understand the pain and grief of the victims and their loved ones, but my heart goes out to them.” The horrific attack early Friday in Aurora has revived the debate over gun control in the United States, and drew condemnation by Obama and his Republican White House rival Mitt Romney. A further 58 people were wounded.