Police to Enter Colorado Suspect's Booby-Trapped Home
Obama said the administration will do everything possible to support the community. The White House said Obama was informed of the shooting by Homeland Security Adviser John Brennan at 5:26 a.m. EDT.
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 town is also 20 miles northeast of Littleton, where two teen gunmen massacred 13 people in a suicide attack at Columbine High School in 1999.
The massacre stunned Aurora and much of the nation, evoking memories of the 1999 massacre at Columbine High School in Littleton, 17 miles (27 km) from Aurora, where two students opened fire and killed 12 students and a teacher.
It also resonated in the U.S. presidential race as both President Obama and Romney toned down their campaigns, pulled their ads from Colorado and dedicated their scheduled events to the victims on Friday.
Chris Henderson, Aurora's deputy fire chief, said Holmes' living room was found crisscrossed with trip wires connected to what appeared to be plastic bottles containing an unknown liquid.
A law enforcement source told Reuters the suspect had also set a timer to turn on loud music in his apartment—playing the same song over and over again—apparently in an attempt to prompt a complaint and lure police into a trap.
"If he was shot and killed, it is without a doubt that these ... booby traps were there to murder and inflict casualties upon first responders," the source said.
With Holmes in jail and awaiting an initial court appearance on Monday morning, police have declined to reveal what he has told investigators and would not discuss possible motives for the shooting rampage.
Meanwhile little has surfaced from the suspect's past to suggest he was capable of such violence.
Raised in a middle-class San Diego neighborhood, he earned a degree in neuroscience from the University of California at Riverside before seeking his graduate degree from the University of Colorado.
Holmes was described by acquaintances as bright but was in the process of dropping out of his graduate program at the time of the shooting, according to the university.
Billy Kromka, a pre-med student who worked alongside Holmes in a neuroscience research lab last year, said he was astonished when he saw a picture of the accused gunman.
"He basically was socially awkward but not to the degree that would warrant suspicion of mass murder or any atrocity of this magnitude," Kromka told Reuters in an interview. "I did not see any behavior he exhibited that indicated he would be capable of an atrocity of a magnitude like this."
Kromka, 19, said he knew Holmes to sometimes play video games in the lab when he was supposed to be working, and said he seemed to be influenced by movies and the media.