Twelve people are dead and 58 others injured after a midnight showing of the latest Batman installment "The Dark Knight Rises" in the U.S. turned from an action-packed screening into a deadly shooting spree.

Local media reported a shooter in a bulletproof vest fired at the audience inside the Aurora, Colorado theater, after he hurled tear gas into the crowd.

Many witnesses initially believed the gunman was part of an act, since he apparently carried out the shooting during a shooting scene in the film.

Police are questioning 24-year-old suspect James Homes, but have yet to announce a motive for the crime.

The Federal Bureau of Investigation said there was no indication the shooting was linked to any kind of terrorist group.