Gunman had spent months planning massacre

Former student James Holmes, 24, had received deliveries of thousands of rounds of ammunition over the past 16 weeks as well as chemicals and materials used to rig his flat with dozens of bombs.

Detectives were finally able to access his apartment in suburban Denver yesterday after experts cleared it of boobytraps and explosives, two days after he opened fire and set off gas canisters in a cinema in Aurora minutes into the premiere of the new Batman film, The Dark Knight Rises.

Authorities would not discuss a motive for the attack, one of the deadliest mass shootings in recent US history, but said it was clear that it had been planned well in advance, with records showing Holmes receiving deliveries by post to his home and school for four months and buying thousands of rounds of ammunition on the internet.

Reports over the weekend suggested Holmes described himself as “The Joker” upon his arrest but facts about the gunman remained scarce last night.

He had recently withdrawn from a competitive graduate programme in neuroscience, and neighbours and former classmates in California have said he was a smart loner who said little.

Holmes is in solitary confinement for his protection at a county detention facility on suspicion of multiple counts of first-degree murder. He is due in court for an initial hearing today and had been appointed a lawyer, authorities said.

Aurora police chief Dan Oates said: “He had a high volume of deliveries to both his work and home address. We think this explains how he got his hands on the magazine ammunition.

“What we’re seeing here is evidence of some calculation and deliberation.”

Barack Obama flew into Colorado yesterday to meet victims of the massacre and their families, briefly silencing the presidential campaign. Both Mr Obama and Republican challenger Mitt Romney have cut short their schedules and pulled advertising in the state out of respect for the victims. Mr Obama said in his weekly radio and internet address that he hoped everyone took time this weekend “for prayer and reflection – for the victims of this terrible tragedy, for the people who knew them and loved them, for those who are still struggling to recover”.

The President said Americans should also think about “all the victims of the less publicised acts of violence that plague our communities on a daily basis. Let us keep all these Americans in our prayers.”

Meanwhile families yesterday grieved and waited at hospitals, which reported at least seven wounded still in a critical condition and others with injuries that will probably be permanent.

Six-year-old victim Veronica Moser had gone to the cinema with her mother Ashley, who is drifting in and out of consciousness in an intensive care unit with bullets lodged in her throat and a gunshot wound to her stomach.

“Nobody can tell her about it,” Ashley’s aunt Annie Dalton said. “She is in critical condition, but all she’s asking about is her daughter.”

Another victim, Matt McQuinn, 27, was killed after diving in front of his girlfriend and her older brother to shield them from the gunfire.