Security was tight at the hearing. Spectators had to pass through a metal detector and then were searched again before entering the courtroom. At least nine armed officers stood guard inside, some of them scanning the audience packed with reporters and victims' family members.
Holmes did not speak during the hearing. His bushy hair and long beard contrasted with the bright red hair and close-cropped looks he sported during previous appearances.
During portions of the hearing, family members of victims held one another, sobbing.
Earlier in Monday's hearing, police Officer Jason Oviatt -- the first officer to encounter Holmes after the rampage ended -- testified that Holmes seemed "very, very relaxed."
Holmes, his pupils dilated, sweating and smelly, didn't struggle or even tense his muscles as he was dragged away to be searched.
"He seemed very detached from it all," Oviatt testified, describing Holmes as unnaturally calm amid the chaos and carnage.
Oviatt testified Monday that within minutes of the first calls, he responded to the theater and found Holmes standing outside in a helmet and gas mask, his hands atop a white coupe that turned out to belong to him.
At first, Oviatt said, he thought Holmes was a police officer, but as he drew within 20 feet, he realized something was terribly wrong.
"He was just standing there. All the other officers were running around, trying to get into the theater," Oviatt said.
A trail of blood led from the theater. The rifle that authorities believe Holmes used in the attack lay on the ground near the building.
Holmes calmly complied with all Oviatt's orders, the officer testified.
Another officer, Aaron Blue, testified later that Holmes matter-of-factly told him, without prompting, about the complex web of explosives that authorities would later find in his Aurora apartment.
He told Blue that the devices "wouldn't go off unless we set them off."
Holmes was a doctoral student in the neuroscience program at the Anschutz Medical Campus of the University of Colorado, Denver, in Aurora, until he withdrew a month before being arrested outside the bullet-riddled movie theater. He had been a patient of a University of Colorado psychiatrist, according to a court document filed by his lawyers.
His only brush with the law in Colorado appears to have been a 2011 summons for speeding from Aurora police.
If Holmes is ruled incompetent to stand trial, the hearing could provide the best opportunity for victims and the public to understand what happened and why.
To at least one victim, it doesn't matter if Holmes stands trial.
"I obviously don't want him to walk, but as long as he doesn't see the light of day again, it doesn't really much concern me beyond that," said Stephen Barton, who suffered wounds on his face, neck and upper torso in the shooting that night. "To me, I see the trial as being an opportunity to learn more about what happened that night beyond just my own personal recollection."