The shooting suspect who went on a deadly rampage inside a Colorado cinema planned the attack with "calculation and deliberation,'' police said, receiving deliveries for months which authorities believe armed him for battle.
Authorities on Saturday removed dangerous explosive materials from inside James Holmes' Denver apartment a day after police said he opened fire and set off gas canisters in a cinema minutes into the premiere of the Batman film The Dark Knight Rises. The attack left 12 people dead and 58 injured.
His apartment was rigged with jars of liquids, explosives and chemicals that were booby trapped to kill "whoever entered it,'' Aurora Police Chief Dan Oates said, noting it would have likely been one of his officers.
All hazards have been removed from the Holmes' apartment and residents in surrounding buildings can return home, police said.
The exception was Holmes' apartment building, where authorities were still collecting evidence. Inside the apartment, authorities began covering the windows with black plastic to prevent onlookers from seeing in. Before they did, a man in an ATF T-shirt could be seen measuring a poster on a closet that advertised a DVD called Soldiers of Misfortune. The poster showed several figures in various positions playing paintball, some wearing masks.
Authorities wouldn't discuss a motive for one of the deadliest mass shootings in recent US history, as makeshift memorials for the victims sprang up and relatives began to publicly mourn their loved ones.
Holmes had recently withdrawn from a competitive graduate programme in neuroscience at the University of Colorado-Denver, where he was one of six students at the school to get National Institutes of Health grant money. He recently took an intense three-part, oral exam that marks the end of the freshman year of the four-year program there, but university officials would not say if he passed, citing privacy concerns.
In a resume posted on Monster.com, Holmes listed himself as an "aspiring scientist'' and said he was looking for a job as a laboratory technician.
The resume, first obtained by The Press-Enterprise in Riverside, paints a picture of a brilliant young man brimming with potential: He worked as a summer intern at the Salk Institute for Biological Studies in La Jolla in 2006 and mapped the neurons of Zebra finches and studied the flight muscles of hummingbirds while an undergraduate at the University of California, Riverside. He also worked as a summer camp counsellor to underprivileged children at a Jewish camp in Los Angeles in 2008.
Still, neighbours and former classmates in California said although Holmes was whip-smart, he was a loner who said little and was easily forgotten until this week.
Holmes apparently had prepared the attack at the Aurora cinema well in advance, receiving multiple deliveries by mail for four months to his home and school and buying thousands of rounds of ammunition on the Internet, Oates said.
"He had a high volume of deliveries,'' Oates said. "We think this explains how he got his hands on the magazine, ammunition,'' he said, as well as the rigged explosives in his apartment.
"What we're seeing here is evidence of some calculation and deliberation,'' Oates added.
Federal authorities detonated one small explosive and disarmed others inside Holmes' apartment after sending in a robot to take down a trip wire, FBI Special agent James Yacone said. Bomb technicians then disarmed what he called a "hypergolic mixture'' and an improvised explosive device containing an unknown substance. There also were multiple containers of accelerants, he said.
"It was an extremely dangerous environment,'' Yacone said, saying anyone who walked in would have sustained "significant injuries'' or been killed.
Outside the apartment, police arranged plastic storage boxes and large white plastic bags, possibly for evidence, although no officials were available to confirm the purpose of the containers.
Holmes, 24, was in solitary confinement for his protection at a county detention facility Saturday, held without bond on suspicion of multiple counts of first-degree murder. He was set for an initial hearing on Monday and had been appointed a public defender, authorities said.
Stories of the dead began to emerge, including that of a 6-year-old girl and a man who died on his 27th birthday and a day before his anniversary. Families grieved and waited at hospitals, which reported at least seven wounded still in critical condition on Saturday (local time) and others with injuries that likely are permanent.
Veronica Moser, 6, had gone to the movies with her mother, who was drifting in and out of consciousness in a hospital intensive care unit, bullets lodged in her throat and a gunshot wound to her abdomen.
"Nobody can tell her about it,'' Annie Dalton said of her niece, Ashley Moser. "She is in critical condition, but all she's asking about is her daughter.''
Veronica had just started swimming lessons on Tuesday , Dalton said.
"She was excited about life as she should be. She's a 6-year-old girl,'' her great aunt said.
Another victim, 27-year-old Matt McQuinn, was killed after diving in front of his girlfriend and her older brother to shield them from the gunfire, said his family's attorney, Rob Scott of Dayton, Ohio.
Alex Sullivan had planned a weekend of fun, first ringing in his 27th birthday with friends at the special midnight showing of The Dark Knight Rises and then celebrating his first wedding anniversary on Sunday (local time).
"He was a very, very good young man,'' said Sullivan's uncle, Joe Loewenguth. "He always had a smile, always made you laugh. He had a little bit of comic in him.''
Oates said Holmes used a military-style semi-automatic rifle, a shotgun and a pistol to open fire on the unsuspecting theater-goers. He had bought the weapons at local gun stores within the last two months. He recently purchased 6,000 rounds of ammunition over the Internet, the chief said.
Holmes also bought an urban assault vest, two magazine holders and a knife for just over $300 NZ$375) on July 2 from an online supplier of tactical gear for police and military personnel, according to the company.
Chad Weinman, CEO of TacticalGear.com, said his company processes thousands of orders each day, and there was nothing unusual in the one that Holmes placed.
"Everything Mr. Holmes purchased on July 2 is commercially available,'' Weinman said, adding he was "appalled'' that the material was sold to Holmes before the shooting.
The Batman movie, the last in the trilogy starring Christian Bale, opened worldwide on Friday with midnight showings in the US.
The Dark Knight Rises earned $30.6 million (NZ$38.3m) in Friday morning midnight screenings.
After buying a ticket to the movie, Holmes went into the cinema and propped open an exit door several minutes into the film, a federal law enforcement official said. The suspect then returned in protective gear and with high-powered weapons and opened fire, shooting scores of people and picking off victims who tried to flee, officials said.
The shooting was the worst in the US since the November 5, 2009, attack at Fort Hood, Texas. An Army psychiatrist was charged with killing 13 soldiers and civilians and wounding more than two dozen others.