20 July 2012
Last updated at 13:39 ET
Twelve people have been killed and 59 more injured at a shooting at a screening of the latest Batman film near the US city of Denver.
In the hours after the shooting, Tom Sullivan pleaded with news media for help finding his son Alex, who celebrated his 27th birthday by attending the Batman show. He made the appeal at a local high school where police gathered witnesses for interviews.
As of Friday afternoon, police had yet to identify all of the deceased.
Witnesses say a gunman wearing a gas mask and other tactical kit opened fire after tossing two tear gas grenades into the auditorium during a midnight showing of The Dark Knight Rises, at a cinema in Aurora.
Ten people were killed at the cinema and two others died later in hospital of their wounds. One person watching the film in the adjacent theatre was shot when a bullet went through the wall.
An eyewitness told the BBC that several minutes in to the film, the man came through the right-hand exit nearest the front row. "He fired a canister into the air. It shot it right into the air, then I started to hear the bang, bang, bang of a gun," the witness, identified only as Pam, said.
The FBI, which is working with the police, says there is no terrorism link so far in the investigation.
A 24-year-old local man - named as James Holmes - was arrested in a car park nearby in possession of a rifle, handgun and knife. One other gun was recovered from the theatre. The suspect told police that explosives were stored at his home.
Authorities say the process of clearing Mr Holmes' apartment will be long and slow.
President Barack Obama cut short a planned campaign rally in Florida. He asked for a moment of silence, telling supporters: "There are going to be other days for politics. This, I think, is a day for prayer and reflection."