Police Say 12 Are Killed at Showing of Batman Movie in Colorado Barry Gutierrez/Associated Press Witnesses to the shooting in Aurora, Colo., were brought to Gateway High School for questioning after a gunman opened fire at a midnight showing of "The Dark Knight Rises." AURORA, Colo. - A former neuroscience honors student dressed head to foot in body armor and brandishing three weapons, including an assault rifle, opened fire in a crowded theater at a midnight showing of the new Batman movie in a Denver suburb early Friday, killing at least 12 people and wounding 59 others, police and federal officials said. The suspect, James Holmes, 24, told the police after his arrest that he had booby-trapped his Aurora apartment with explosive devices, leading the police to evacuate five buildings in the neighborhood as they sought to disable what they described as "incendiary and chemical devices" that appeared to be rigged to trip wires. "We have an active and difficult scene," said Aurora's police chief, Dan Oates. It may be resolved in hours or days. We simply don't know how we're going to handle that. During the attack, witnesses said, Mr. Holmes entered through a side door of the packed theater wearing a gas mask. He set off two smoke devices before firing randomly at audience members, who had just settled into their seats. Within minutes, he was arrested in a parking lot behind the theater near his car, the police said. Mr. Holmes had apparently planned the attack for some time. In addition to the gas mask, he wore body armor and a helmet and was dressed completely in black. His gear included a throat protector, a groin protector, a bulletproof vest and leggings, and tactical gloves. He entered the theater with an AR-15 assault rifle, a Remington 12-gauge shotgun and a .40-caliber Glock handgun. A fourth gun, another Glock pistol, was found in his car. "This is the act, apparently, of a very deranged mind," said Gov. John Hickenlooper of Colorado. A federal law enforcement official said investigators knew where at least two of the guns had been purchased, and suggested that they were bought recently, but would not say where or precisely when. Another law enforcement official said that information investigators had obtained about the purchase of the AR-15 rifle indicates that it was bought locally and apparently legally, as were the other guns, adding, "there's nothing nefarious there." The suspect was in possession of a clip with more than 20 rounds, a federal official said, that would have been illegal under an assault rifle ban that expired in 2004. The Bureau of Alcohol, Tobacco, Firearms and Explosives has handed over information on where and when the guns were purchased to the police in Aurora. Investigators have uncovered no solid indications of a motive and no evidence of any past aberrant behavior. "He's not on anybody's radar screen - nothing," the law enforcement official said, adding that investigators were sifting through social media sites in an effort to determine whether Mr. Holmes had ever posted anything that might indicate some violent tendencies. The second law enforcement official, speaking of Mr. Holmes, said: "This guy is somewhat of an enigma. Nobody knows anything about him. The shooting took place at the midnight showing of "The Dark Knight Rises," in a theater packed with families and children. It was not immediately clear whether the gunman ran out of ammunition or stopped shooting for some other reason. Commissioner Raymond W. Kelly of the New York City police, who dispatched officers to patrol screenings of the film in New York, said he had been told the shooting suspect had hair painted red and said he was the Joker. That detail could not be initially confirmed. The authorities believe that Mr. Holmes acted alone, and that the death toll may increase because some of the wounds were serious. Mr. Holmes's family in San Diego asked for privacy in a statement released by the city's Police Department. "Our hearts go out to those who were involved in this tragedy and to the families and friends of those involved," the statement said. We ask that the media respect our privacy during this difficult time. Our family is cooperating with authorities in both San Diego, California and Aurora, Colorado. We are still trying to process this information and we appreciate that people will respect our privacy. Dan Frosch reported from Aurora, William K. Rashbaum and Timothy Williams from New York, and Michael S. Schmidt from Washington. Reporting was contributed by Peter Baker from West Palm Beach, Fla.; Jennifer Medina and Michael Cieply from Los Angeles, Elisabeth Bumiller, Jennifer Steinhauer and John Cushman from Washington; and J. David Goodman, Victoria Shannon, Emma G. Fitzsimmons, Jennifer Preston, Wendy Ruderman and Thomas Kaplan from New York. Kitty Bennett and Sheelagh McNeill contributed research.