THE apartment where James Holmes is believed to have planned his attack was the scene of a massive security operation last night, amid police claims that it contained a large quantity of explosives linked to a "pretty sophisticated" booby trap.
Neighbours, who described the 24-year-old medical school dropout as a "loner", were evacuated early yesterday after officers spotted what they described as "buckets of extra ammunition" and "some kind of chemical" inside the third-floor living area.
A stereo had been left playing a song on repeat, at high volume, while a poster of the actor Will Ferrell, in the film Anchorman, was visible on the kitchen wall, according to reporters who arrived outside the modest brick building before police had established a security perimeter.
Holmes, who is muscular, 6ft 3in tall and has dark hair, moved into the property, about four miles from the cinema, in May 2011.
He was about to begin studying for a PhD in neuroscience at the University of Colorado-Denver, describing himself on the landlord's application as a "quiet and easy-going medical student".
One of Holmes's courses covered the "biological basis of psychiatric and neurological disorders".
The university website lists him as having made a presentation to fellow students in that course a few months ago, on the subject of "micro-RNA biomarkers".
He suddenly dropped out of university a month ago, a spokesman said, without giving a specific reason.
Neighbours had noticed nothing suspicious in his behaviour since, describing him as a reclusive type who ignored them even when they said hello.
"No one knew him. No one," the occupant of a flat in the building told reporters.
Police said Holmes had no criminal record. He appears to have acted alone, and has no ties to terrorist organisations. Early reports that he drove to the cinema in a car with Tennessee plates turned out to be false.
Originally from California, Holmes went to high school in San Diego, where his parents still live.
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