12 dead after shooting at Colorado movie theater

At least 12 people are dead and as many as 50 were shot after a gunman opened fire at a suburban multiplex theater outside of Denver around 12:30a.m. MDT.

A midnight showing of "The Dark Knight Rises" turned deadly when a gunman opened fire at the Century 16 theater in Aurora, Colorado. Ten people were killed inside the theater and another two have since died in area hospitals.

The suspect opened fire in theater nine, the largest screen at the complex. Witnesses in a theater next door report hearing gunshots and explosions, but many thought that was coming from the movie.

Witnesses tell police that before the gunman started shooting, he released some sort of canister, and then there was a hissing sound and some gas emerged.He was reportedly wearing a gas mask and a vest.

At least 48 people are being treated at Denver area hospitals - the youngest a 3-month-old baby.

"This is a horrific event. Our hearts go out to the families" said Aurora Police Chief Dan Oates. "I'm saying approximately 50 were injured. We can't get a firm count right now and there may be some double counts if a victim was taken to one hospital and then transported to another."

"I heard the sound of metal canisters clinking around, and then I saw plumes of smoke" said one witness. â??It took me a second to realize what was going on, and as people were running away, I hit the ground so I wouldn't be hit."

When police arrived on the scene they arrested a suspect in a parking lot behind the theater. Guns and a gas mask were in a nearby car. The man in custody also mentioned "possible explosives in his residence," so officials also are dealing with that potential threat. Police evacuated the Denver-area apartment.

FBI agents and police used a hook and ladder fire truck to reach Holmes' apartment in Aurora, Oates said. They put a camera at the end of a 12-foot pole inside the apartment, and discovered that the unit was booby trapped. Authorities evacuated five buildings as they tried to determine how to disarm flammable and explosive material

Officials identified the shooter as 24-year-old James Holmes. He was a student at the University of Colorado School of Medicine in Denver until last month, spokeswoman Jacque Montgomery said. She did not know when he started school or why he withdrew.

Oates said there's no evidence of any other attackers. There was also no immediate word of any motive.

FBI spokesman Jason Pack said there's no indication in the investigation so far of any connection to terror groups.

Police have taken the witnesses to a nearby hospital for questioning.

President Barack Obama issued a statement early Friday morning: "Michelle and I are shocked and saddened by the horrific and tragic shooting in Colorado. Federal and local law enforcement are still responding, and my Administration will do everything that we can to support the people of Aurora in this extraordinarily difficult time. We are committed to bringing whoever was responsible to justice, ensuring the safety of our people, and caring for those who have been wounded. As we do when confronted by moments of darkness and challenge, we must now come together as one American family. All of us must have the people of Aurora in our thoughts and prayers as they confront the loss of family, friends, and neighbors, and we must stand together with them in the challenging hours and days to come."

It's the worst mass shooting in Colorado since the Columbine High School massacre on April 20, 1999. Students Eric Harris, 18, and Dylan Klebold, 17, opened fire at the school in the Denver suburb of Littleton, about 15 miles west of Aurora, killing 12 classmates and a teacher and wounding 26 others before killing themselves in the school's library.

It was the worst mass shooting in the U.S. since the Nov. 5, 2009 attack at Fort Hood, Texas, when an Army psychiatrist killed 13 soldiers and civilians and more than two dozen others wounded.

Aurora is on Denver's east side and is Colorado's third-largest city with 327,000 residents. It is home to a large Defense Department satellite intelligence operation at Buckley Air Force Base, as well as The Children's Hospital, the University of Colorado Hospital and a future Veterans Affairs hospital.

The movie opened across the world Friday with midnight showings in the U.S. The shooting prompted officials to cancel the Paris premiere, with workers pulling down the red carpet display at a theater on the famed Champs-Elysees Avenue.

New York City's police commissioner says the

NYPD is providing coverage

at theaters featuring the new Batman movie "as a precaution against copycats and to raise the comfort levels among movie patrons."

(Information from CBS News and the Associated Press was used in this report)