The first of some 9,000 potential jurors will report to court in Colorado on Tuesday as selection begins for the trial of James Holmes, the former neuroscience graduate student who killed 12 people in July 2012 at a midnight screening of a Batman movie.
Holmes, 27, has pleaded not guilty by reason of insanity to 166 charges of murder, attempted murder and explosives offenses. He was arrested wearing a gas mask, helmet and body armor at the scene of the shooting rampage, in which 70 people were also hurt.
His lawyers say Holmes was suffering a "psychotic episode" at the time. He could face the death penalty if convicted.
Jury selection may take up to four months as Arapahoe County District Court Judge Carlos Samour seeks to narrow the large field to a panel of 12 jurors and 12 alternates.
So many people were summoned because of the difficulty expected in finding an impartial jury for such a high-profile, emotive case. Each will be questioned about their views on topics including insanity defenses and the death penalty.
Holmes, who first appeared in court in the days after the shooting looking dazed and with his hair dyed red-orange, is expected to be back in a courtroom at the Arapahoe County Justice Center on Tuesday afternoon when the first group of 250 are addressed by the judge, watch a video on jury duty, and fill out questionnaires.
The trial has been delayed several times, mostly by wrangles over the Southern California native's state of mind when he opened fire with a handgun, shotgun, and semi-automatic rifle inside the crowded premier of "The Dark Knight Rises" film at the Century 16 multiplex in Aurora, an eastern suburb of Denver.
Holmes has undergone two-court ordered sanity exams since his arrest. They have produced dozens of hours of video and thousands of documents, all sealed by the judge, but according to court papers they provided conflicting results.
At a preliminary hearing in January 2013, prosecutors gave a preview of the evidence that will be used against him at trial.
First responders testified to horrific scenes in the body-strewn theater 9, where blood pooled on the floor and the movie still played, its soundtrack blaring. A fire alarm rang, strobe lights flashed, and wounded victims screamed.
One policeman said he initially mistook Holmes for a fellow officer because the gunman was wearing body armor, but that he realized it was not police issue gear and he saw that Holmes was acting oddly. He was ordered to the ground and handcuffed.
Another officer testified that when Holmes was then asked whether he had an accomplice, he replied: "No, it's just me."
