Moviegoers inside a Denver, Colorado theater thought the gas they saw and shots they heard were part of a screening of 'The Dark Knight Rises' they were watching.  In reality, a gunman had begun to open fire on the crowd.  Today, police confirm 12 are dead and as many as 38 others are injured following the deadly spree.

Click READ MORE for video from the scene.

WARNING:  VIDEO IS RAW AND CONTAINS DISTURBING IMAGES

Denver Police Chief Daniel Oates says a masked gunman dressed in black released a canister containing gas before he began shooting patrons at the Century 16 theaters at the Aurora Mall at 12:45AM MDT.

WARNING:  RAW VIDEO

 

Hayden Miller tells KUSA TV what he witnessed:

“Like little explosions going on and shortly after that we heard people screaming,” he told the station.

Hayden said he mistook what he heard as a louder movie next door. But then he saw “people hunched over leaving theater.”

The youngest of the dead is just 6-years old.  A 13-month old was also among the injured.

The 24-year old gunman, identified as James Holmes, had arrived to the theater wearing a gas mask and bulletproof vest.  Holmes is now in police custody.  Authorities say he was found with two more weapons in tow.  Additional bombs were also discovered at the suspects Aurora, Colorado home.