CENTENNIAL, Colo. — As officials this week laid out the most detailed portrait yet of last year's Aurora movie theater massacre, they also mapped sometimes paradoxical behavior by the man accused of the rampage, James Holmes.

At a hearing to determine whether the former neuroscience graduate student should stand trial for the shooting, detectives Tuesday testified that Holmes spent more than two months assembling an arsenal for the assault on a midnight screening of "The Dark Knight Returns."

He bought his tickets nearly two weeks before the July 20 massacre. He rigged an elaborate booby-trap system in his apartment to distract police from the carnage at the theater, though the trap was never sprung, they testified.