USA: Gunman kills 12 in Colorado cinema rampage The United States is in shock after a gunman wearing a gas mask killed 12 people at a midnight screening of the new Batman film. Police say the man hurled a gas canister into the auditorium and began firing at cinemagoers in Denver, Colorado, sparking pandemonium. More than 50 people, including children, were wounded in the attack as "The Dark Knight Rises" was being shown in the Aurora suburb. "A cop came walking through the door holding a little girl in his arms and she wasn't moving," said witness Alex Milano. I had heard another witness who was in my theatre....She was on the phone and the really messed-up part for me was she told whoever she was talking to that she saw bullet holes in the little girl's back. A man detained in connection with the attack has been named as James Holmes, a 24-year-old former medical student. The suspect was arrested in the car park behind the cinema. Police say he was carrying a knife, a rifle and a handgun and that his apartment has been booby-trapped with sophisticated explosives which could take days to defuse. The massacre has evoked memories of the 1999 shooting at Columbine High School in Denver when two students killed 12 students and a teacher. More about: Cinema, Denver, Shootings, Victims