Batman cinema shooting: US mourning Aurora victims
The US has begun mourning after 12 people were killed and 70 wounded in a shooting at a midnight showing of the new Batman film, the Dark Knight Rises.
US President Barack Obama ordered flags flown at half mast and said the day was "for prayer and reflection".
A man wearing a gas mask and body armour threw tear gas canisters at movie-goers in Aurora, Colorado, then fired on the crowd, witnesses said.
James Holmes, 24, was arrested outside the cinema near Denver, police said.
He will appear at Arapahoe County District Court, in nearby Centennial, Colorado, on Monday at 09:30 local time (15:30 GMT).
He was said to be armed with a rifle, a shotgun and two pistols when he launched his assault. All were bought legally within the past few months, US media reported.
In New York, Police Commissioner Raymond Kelly said the suspect had dyed his hair red and told police he was the Joker, Batman's infamous nemesis.
Cinemas in that city tightened security at Batman showings following the attack, and the French premiere of the film in Paris was cancelled.
The film's director, Christopher Nolan, issued a statement expressing his horror.
"The movie theatre is my home, and the idea that someone would violate that innocent and hopeful place in such an unbearably savage way is devastating to me," Nolan said.
"Nothing any of us can say could ever adequately express our feelings for the innocent victims of this appalling crime, but our thoughts are with them and their families."
Despite a strong past academic record, James Holmes was in the process of withdrawing from a doctoral programme in neuroscience at the University of Colorado-Denver, a university spokeswoman told the Associated Press.
Authorities have established no terrorism link, nor any motive, and Mr Holmes had no criminal record in Aurora.
His family said in a written statement: "Our hearts go out to those who were involved in this tragedy and to the families and friends of those involved. We ask that the media respect our privacy during this difficult time."
On Friday afternoon, police were still working to identify the dead, 10 of whose bodies still lay inside the cinema.
One woman known to have been killed was Jessica Ghawi, also known as Jessica Redfield, an aspiring broadcaster and a regular blogger.
In June, Ms Ghawi, 24, narrowly missed being caught in a shooting rampage in Toronto, leaving the scene five minutes before a man opened fire at the Eaton Centre shopping mall.
After the shooting, police said that - acting on information from the suspect - they had discovered that his home in the north of Aurora had been booby-trapped. Incendiary devices with chemical elements and trip wires were in the flat, police said.
"We have an active and difficult scene there," said Aurora Police Chief Dan Oates, who added it could be hours or days before the apartment was cleared.
The attack began minutes into the showing at about 00:30 local time (06:30 GMT), when the gunman apparently entered the cinema through an emergency exit door near the front of the auditorium. Reports said the attacker had a ticket but left the cinema, pretending to receive a phone call, before returning full armed.
He wore a bullet-proof vest, tactical body armour and gloves, and was carrying an AR-15 military-style, semi-automatic rifle, a shotgun and two pistols, police said.
He threw two tear gas grenades then opened fire with a rifle. There was chaos as movie-goers fled, some dressed in costume as heroes and villains.
Ten people were killed at the cinema and two others died later in hospital of their wounds. Scores of people, some in a critical condition, were taken to four hospitals.
The casualties included a four-month-old baby, who was released from hospital after treatment, and a six-year-old child.
'Firing at random'
One witness said the gunman had been "slowly making his way up the stairs and just firing - picking random people". At least one person in an adjacent auditorium was injured when a bullet went through the wall, police said.
Another eyewitness, identified only as Pam, told the BBC: "He fired a canister into the air. It shot right into the air, then I started to hear the bang, bang, bang of a gun.
"I crawled my way through the row. Luckily the exit was close to where I was sitting so I got out pretty fast. I heard more shots as I left."
Another eyewitness, Salina Jordan, 19, told the Denver Post she had seen one girl shot in the cheek, and a girl who appeared to be about nine years old with a gunshot wound to the stomach.
Informed of the massacre at dawn, President Obama briefly addressed a campaign rally before returning to the White House to address the situation.
"There are going to be other days for politics," he said.
"This, I think, is a day for prayer and reflection."
Reported by BBC.
Reported by BBC.