The gunman who killed 12 people and wounded dozens more at a midnight showing of the "The Dark Knight Rises'' near Denver had browsed weapons in a San Diego pawn shop.
The owner of Hillcrest Pawnbrokers said he immediately recognized 24- year-old James Eagan Holmes as someone who had been in his shop. Holmes grew up in Rancho Penasquitos, where his parents still live.
Holmes, a 2006 graduate of Westview High School, was arrested outside the theater in the parking lot without a struggle after the roughly 12:30 a.m. shooting Friday and is in the Arapahoe County Jail, pending his arraignment. His father, Bob Holmes, the manager of a software company, flew to Denver yesterday under police escort.
David Casper said Holmes spoke with him about the types of weapons used in the shooting: an AR-15 -- a civilian version of the M-16 that fires .227- caliber bullets -- a pump, 12-gauge shotgun, and two semiautomatic Glock .40- caliber pistols.
"When they mentioned the type of firearms, I was kind of taken aback, because those are exactly the type of firearms I would have recommended,'' Casper said in televised reports.
Around daybreak, San Diego police went to Holmes' childhood home on Sparren Avenue as television news crews began to assemble outside. ABC News spoke with his mother, Arlene, a registered nurse, who confirmed her son was the suspect.
San Diego police were devoting "extra attention'' to theaters were the Batman movie is showing, San Diego police Lt. Andra Brown said. "Our patrol officers are directed to conduct some extra patrols at movie theaters in their commands as time permits.''
No problems were reported at Friday night showings.
Speaking for the Holmeses, attorney Lisa Damani said their "hearts go out'' to the victims and their loved ones.
"We are still trying to process this information, and we appreciate that people will respect our privacy,'' she said.
Holmes graduated with honors from the UC Riverside two years ago with a bachelor's degree in neuroscience and enrolled in graduate school at the University of Colorado at Denver in June 2011.
As of this week, he was "in the process of filling out the paperwork to voluntarily withdraw'' from the doctorate program, according to a statement from the Denver campus.
Holmes worked as a student intern at the Salk Institute in La Jolla and at the biotechnology "boot camp'' at Miramar College in the summer of 2006, the U-T San Diego reported.
Shortly before 7:30 a.m. Friday, officers escorted the suspect's luggage- toting father, who U-T San Diego reported is a scientist with degrees from Stanford, UCLA and UC Berkeley, out of the home and took him away in an unmarked police car.
During the deadly rampage, the gunman was dressed all in black and wore a bullet-resistant vest, leggings and throat gear, a riot helmet and a gas mask.
"There were many, many rounds fired,'' Aurora police Chief Dan Oates said.
Ten people died in the theater. Two others died at hospitals, Oates said. The wounded -- including an infant, at least one Navy sailor and two Air Force personnel -- were taken to six hospitals. Eleven were said to be in critical condition.
The theater is about five miles from Holmes' third-floor apartment, which authorities found booby-trapped with trip wires apparently attached to various incendiary or chemical devices, Oates said.
Oates said investigators were "confident'' the suspected shooter acted alone. All the guns and ammo were legally purchased, he said.
Authorities said Holmes had no criminal record in Colorado, just a citation for speeding that was issued this past fall.
