People gather outside the Century 16 movie theatre in Aurora, Colo., at the scene of a mass shooting early Friday morning, July 20, 2012. Police Chief Dan Oates says 14 people are dead following the shooting at the suburban Denver movie theater. He says 50 others were injured when gunfire erupted early Friday at the Aurora theater. Oates says a gunman appeared at the front of one of the Century 16 theaters.
The shooting occurred during a showing of the latest Batman movie "The Dark Knight Rises," police said.
The violence erupted about 12:30 a.m. MDT as the gunman stood at the front of one of the Century 16 theaters at the Aurora Mall.
"Witnesses tell us he released some sort of canister. They heard a hissing sound and some gas emerged and the gunman opened fire," Oates said at a news conference.
One suspect is in custody and there's no evidence of any additional shooters, Oates said.
There was no immediate word of any motive.
Witness Hayden Miller told KUSA-TV that he was inside Theater 16 and heard several shots.
"Like little explosions going on and shortly after that we heard people screaming," he told the station.
Hayden said at first he thought it was part of a louder movie next door. But then he saw "people hunched over leaving theater."
Two people in critical condition were rushed to the nearby Swedish Medical Center, spokeswoman Nicole Williams said.
She said emergency crews told her staff to prepare for several more patients from the shooting scene.
"We're on standby to receive," she said.
Aurora is located on the southeast outskirts of Denver, about 10 miles from downtown.