Mass shooting at Colorado theater.....12 people dead 50 injured.

A lone gunman dressed in riot gear burst into a movie theater in Aurora, Colo., at a midnight showing of the Batman film "The Dark Knight Rises" and methodically began shooting patrons, killing at least 12 people and injuring at least 50.

The suspect, James Holmes, 24, of Aurora, was caught by police in the parking lot of the Century 16 Movie Theaters, nine miles outside Denver, after police began receiving dozens of 911 calls at 12:39 a.m. MT. Police said the man appeared to have acted alone.

Witnesses in the movie theater said Holmes crashed into the auditorium through an emergency exit about 30 minutes into the film, set off a smoke bomb, and began shooting. Holmes stalked the aisles of the theater, shooting people at random, as panicked movie-watchers in the packed auditorium tried to escape, witnesses said.

"You just smelled smoke and you just kept hearing it, you just heard bam bam bam, non-stop. The gunman never had to reload. Shots just kept going, kept going, kept going," one witness told ABC News.

"I'm with coworkers and we're on the floor praying to God we don't get shot, and the gunshots continue on and on, and when the sound finally stopped, we started to get up and people were just bleeding," another theatergoer said.

Photos: Shooting at 'Dark Knight' Screening at Colorado Movie Theater

Police said 10 victims died inside the theater, while dozens of others were taken to local hospitals, including a child as young as 6 years old.

A San Diego woman identifying herself as James Holmes's mother spoke briefly with ABC News this morning.

She had awoken unaware of the news of the shooting and had not been contacted by authorities. She immediately expressed concern that her son may have been involved.

"You have the right person," she said.

"I need to call the police," she added. "I need to fly out to Colorado."

Holmes was wearing a bullet-proof vest and riot helmet and carrying a gas mask, rifle, and handgun, when he was apprehended, according to police. Holmes mentioned having explosives stored, leading police to evacuate his entire North Aurora apartment complex and search the buildings early this morning.

The highly-anticipated third installment of the Batman triology opened to packed auditoriums around the country at midnight showings on Friday morning, and features a villain named Bane who wears a bulletproof vest and gas mask. Trailers for the movie show explosions at public events including a football game. Though many moviegoers dressed in costume to attend the opening night screening, police have made no statements about any connection between the gunman's motives and the movie.