US President Barack Obama is headed to Colorado to meet victims of the cinema shooting massacre, as Aurora residents flocked to church services in memory of the 12 slain moviegoers.
Another 58 people were injured, nearly all of them shot, when the gunman, dressed in black and wearing body armour and a gas mask, burst into the packed Batman premiere The Dark Knight Rises shortly after midnight on Friday.
The alleged gunman, 24-year-old James Holmes, emerged from the fire exit, threw two canisters of noxious gas into the crowd, fired one shot up in the air and then began shooting randomly into the panicked crowd.
Police revealed on Sunday that they found Holmes' computer inside his booby-trapped apartment, which could provide crucial details about how he planned and executed the attack, reportedly over a number of months.
Holmes is being held in solitary confinement for his own protection, a police spokeswoman said.
The town's churches were packed on Sunday morning, with some people sobbing - many church-goers said they knew someone involved in the shooting.
"My niece was in the theatre but she was lucky to get out," said 15-year-old student Keshala Ferguson, among a capacity 500-strong congregation at the Queen of Peace Catholic church.
"It was nerve-wracking for her mom, but she's OK. The mass was amazing. Everybody needs to pray."
Calls for another look at America's gun laws are mounting in the aftermath of the tragedy as it emerged that the alleged shooter bought his four weapons legally, as well as thousands of rounds of ammunition on the internet.
Police on Saturday entered the gunman's apartment and revealed the names of the 12 fatalities, including a six-year-old girl whose mother was among those seriously injured.
Aurora, a town outside Denver, Colorado, is 32 kilometres from the scene of the 1999 Columbine High School massacre, in which two students shot dead 13 people before committing suicide.
Police chief Dan Oates also revealed Holmes could have been mistaken for an arriving SWAT officer, because of his full body armour, but praised his men for spotting him as a suspect.
"I can't tell you in that chaos it is quite reasonable that an officer might have confused him for a SWAT officer, a heavily armed officer who was responding to the scene," he told CBS talk show Face the Nation.
The president will meet with families and victims, and is planning to go to a hospital, Hickenlooper said, though it is unlikely that he will stay for a community vigil scheduled in Aurora for the early evening.