[His parents] were aware that his life had begun to unravel over the past year, that for reasons still unclear he was living as a near recluse. He was behaving erratically too, trawling adult sex sites, taking drugs and leaving neighbours in the Denver suburb of Aurora with the impression he was deeply troubled.
Police believe he had grown fixated by the Batman films and there are unconfirmed reports he became hooked on the narcotic prescription painkiller Vicodin, which was found in the system of Heath Ledger, the actor who played the Joker. Ledger died of an overdose in 2008.
Publicly, at least, Holmes’s parents are not saying whether they know or can guess what made him snap, yet it appears that unlike others in America’s roll call of mass killers, he was no sociopath. Nor is there anything to suggest he had endured childhood trauma.
Experts believe it is more likely that Holmes was suffering from a genetic psychotic illness which could have acted like a ‘time bomb’ set to go off any time between the ages of 15 and 25.
Holmes began studying for a PhD in neuroscience at the University of Colorado School of Medicine in Denver last year but dropped out a month ago. The last course he took was in mental illnesses and psychiatric disorders, according to the college.
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