Police describe Colorado shooting as 'calculated and deliberate,' say it may have been planned for months

The film's director, Christopher Nolan, issued a statement on behalf of the cast and crew, expressing their "profound sorrow at the senseless tragedy."

"Nothing any of us can say could ever adequately express our feelings for the innocent victims of this appalling crime, but our thoughts are with them and their families," Nolan said.

"Words cannot express the horror that I feel. I cannot begin to truly understand the pain and grief of the victims and their loved ones, but my heart goes out to them." actor Christian Bales said in a statement.

The attack began shortly after midnight at the multiplex in Aurora. Audience members said they thought it was part of the movie, or some kind of stunt associated with it.

The film has several scenes of public mayhem -- a hallmark of superhero movies. In one scene, Bane leads an attack on a stock exchange, and in another he leads a shooting and bombing rampage on a packed football stadium.

A federal law enforcement official said Holmes bought a ticket to the show, went into the theater as part of the crowd and propped open an exit door as the movie was playing. The suspect then donned protective ballistic gear and opened fire, the official said, speaking on condition of anonymity to discuss the ongoing investigation.

At some point, the gunman appeared to have stepped outside because several witnesses saw him come through the door.

"All I saw is the door swinging open and the street lights behind, and you could see a silhouette," said Crofter, who was sitting on the left side of the theater and toward the front.

Sylvana Guillen said the gunman, clad in dark clothing, appeared at the front of the theater as the character Catwoman appeared in the movie. Then they heard gunshots and smelled smoke from a canister he was carrying.

As she and her friend, Misha Mostashiry, ran to the exit, Guillen said, they saw a man slip in the blood of a wounded woman he was trying to help.

Oates said the gunman wore a gas mask and a ballistic helmet and vest, as well as leg, groin and throat protectors. He said he bought four guns from local gun shops in the last 60 days and 6,000 rounds of ammunition, including a drum magazine that could fire 50 to 60 rounds per minute.

"My understanding is that all the weapons that he possessed, he possessed legally. And all the clips that he possessed, he possessed legally. And all the ammunition that he possessed, he possessed legally," Oates said at a press conference Friday.

Seeger said she thought it was showmanship.

"I didn't think it was real," Seeger said. She said she was in the second row, about four feet from the gunman, when he pointed a gun at her face. "I was just a deer in headlights. I didn't know what to do," she said.

Then she ducked to the ground as the gunman shot people seated behind her.

Seeger said she began crawling toward an exit when she saw a girl of about 14 "lying lifeless on the stairs." She saw a man with a bullet wound in his back and tried to check his pulse, but "I had to go. I was going to get shot."

Later, police began entering the theater, asking people to hold their hands up as they evacuated the building.

Some of the victims were treated for chemical exposure apparently related to canisters thrown by the gunman. Those hurt included a 4-month-old baby, who was treated at a hospital and released.