His hair dyed orange, eyes staring out blankly or drooping shut, presumed Colorado gunman James Holmes seemed unhinged Monday as he made a bizarre first appearance in court.
Holmes is accused of shooting dead 12 people and wounding 58 others at a cinema Friday in Aurora, outside Denver, as young moviegoers packed the first midnight screening of the latest Batman film, "The Dark Knight Rises."
Wearing a maroon prison jumpsuit, the 24-year-old graduate school dropout didn't speak as lawyers read out a list of accusations during the short procedural hearing at Arapahoe County District Court in the town of Centennial.
Holmes, a former PhD candidate in neuroscience, appeared unable to follow proceedings as his head bobbed up and down and he alternated between staring out wild-eyed and closing his eyes shut as if drugged or in a daze.
It was not known if he was on some kind of medication and there was no indication when the young man accused of one of America's worst-ever mass shootings might undergo psychiatric evaluation.
Holmes is expected to face 12 murder charges, 58 attempted murder charges for those he wounded, and additional charges related to his booby-trapped apartment at a second appearance next Monday when he will enter a plea.
Prosecutors expect weeks of consultations with families of the victims before deciding whether or not to seek the death penalty.
"We will want to get their input before we make any decision on that," said Arapahoe county district attorney Carol Chambers. "If the death penalty is sought, that is a very long process that impacts their lives for years."
Only one person has been executed in Colorado since 1976.
Denver attorney and legal commentator Scott Robinson said that in his view lawyers for Holmes "have little choice except to enter a plea of not guilty by reason of insanity."
Holmes gave himself up outside the cinema, still clad in the body armor witnesses described the gunman wearing inside, but Chambers said a successful prosecution wasn't a done deal.
"It is a case where we are still looking at the enormous amount of evidence, and we would never presume it is slam dunk," she told reporters, adding that an insanity plea would make the case last a year or more.
Holmes was ordered to remain in Arapahoe County jail, where he is being held in solitary confinement, with no bail allowed.
The gunman emerged from a fire exit on Friday shortly after the film began and threw two canisters of noxious gas into the auditorium.
After firing one round directly into the air with a pump-action shotgun, he began shooting people at random with a military-style assault rifle that could dispatch 50 to 60 rounds a minute, witnesses said.
New York City Police Commissioner Ray Kelly said Holmes had painted his hair reddish orange and claimed he was the Joker, Batman's sworn enemy in the comic book series that inspired the movie.
According to reports and at least one witness, the gunman might have killed more people had his assault rifle not jammed.
Police said Sunday they had found Holmes's computer inside his booby-trapped apartment -- rigged to kill anyone who entered -- which could provide crucial details about how he planned and executed the attack.
Calls to re-examine US gun laws mounted as it emerged that Holmes bought his four weapons legally, as well as thousands of rounds of ammunition on the Internet.
Over eight weeks he stocked up on 6,300 rounds of ammunition: 3,000 for his .233 semi-automatic AR-15 rifle, another 3,000 for his two Glock pistols, and 300 cartridges for his pump-action shotgun.
President Barack Obama paid emotional tribute to the victims and survivors of the Aurora cinema massacre as he visited the town on Sunday.
At an event for US veterans in Reno, Nevada, Obama repeated particular condolences for four people killed who had served in the military.
"These young patriots were willing to serve in faraway lands, yet they were taken from us here at home," he said.
As campaigning ahead of the November election geared up again, Obama's Republican challenger Mitt Romney stressed that now was not the time to discuss new gun legislation.
"Our challenge is not the laws, our challenge is people who, obviously, are distracted from reality and do unthinkable, unimaginable, inexplicable things," Romney said.
The fact Holmes chose not to kill himself, or to engage in a desperate shoot-out with police, "does seem an odd component of this particular case," said Allen McConnell, a psychology professor at Miami University in Ohio.
"His being alive might provide some insights" into the web of circumstances that can potentially lead someone to carry out a mass killing, he told AFP.
Separately, "The Dark Knight Rises" movie had the third largest opening weekend ever.
The movie earned $160.9 million in its first three days, according to Exhibitor Relations, which tracks ticket sales, only behind opening weekend grosses for "The Avengers" and the final Harry Potter movie, "Harry Potter and the Deathly Hallows, Part 2."