ARAPAHOE COUNTY, Colo. (CNN) -- James Holmes, the man accused of killing 12 people at a Colorado movie theater in July, will appear in court Monday for the first day of a preliminary hearing.
For many people, it will be the first time they hear much of the evidence gathered against Holmes.
The hearing is expected to last several days, and Arapahoe County District Judge William Sylvester will determine whether there is enough evidence for Holmes to stand trial.
Sylvester issued a sweeping gag order in July, keeping much of the prosecution's evidence under seal.
Prosecutors are expected to call scores of witnesses and outline the evidence in the case. Holmes' attorneys are expected to present a diminished mental capacity defense.
Holmes, now 25, is accused of killing 12 people and wounding dozens during a midnight screening of the Batman film "The Dark Knight Rises" on July 20 at an Aurora cinema. He faces 166 charges, including murder, attempted murder and weapons offenses.
He was a doctoral candidate in the neuroscience program at the Anschutz Medical Campus in Aurora before he withdrew a month before the shootings.