Holmes has pleaded not guilty by reason of insanity to charges of killing 12 people and wounding 70 others in the July 2012 attack at a suburban Denver movie theater. Holmes' attorneys have acknowledged he was the shooter, but they say he was in the midst of a psychotic episode.
His trial is scheduled to start in February. Prosecutors are seeking the death penalty, which would require them to prove he understood the consequences of his attack.
The defense argues that police violated Holmes' constitutional rights by questioning him before letting him see a lawyer and that anything he told investigators during that time should be struck from the record.
During the pretrial hearing Thursday, defense attorney Tamara Brady aimed pointed questions at police. Officers acknowledged Holmes had asked for a lawyer, and that two defense lawyers had asked to see him, but that no such meeting took place for at least 13 hours.
It was not clear from the testimony when Holmes did meet with an attorney.
One attorney, Iris Eytan, said investigators ignored her demand that they not question Holmes about explosives in his apartment.
Authorities testified that they questioned Holmes anyway, without a defense attorney present. Prosecutors said the questioning was legal because investigators urgently needed to ask Holmes about the bombs to prevent a deadly explosion.
Aurora Police Lt. Thomas G. Wilkes, commander of the team that sealed off Holmes' apartment, said the bombs were so dangerous that officials considered detonating them which they knew would destroy Holmes' building and threaten others rather than risk the lives of bomb squad members by trying to dismantle them.
Ultimately, police disarmed the bombs without explosions.
Holmes was questioned about the bombs about 14 hours after the shootings.
Brady noted that a police audio recording of Holmes' answers doesn't include the first few minutes, and there's no way of knowing what officers told him.
"I assume you did not tell him these statements would be used to get his death," she said to Aurora Det. Craig Appel.
"We didn't talk about death," Appel replied. "There had been enough death that day."
Appel said he had inadvertently turned his recorder off and that he turned it on when he discovered the problem.
Arapahoe County Judge Carlos A. Samour Jr. hasn't said when he will rule on the whether Holmes' statements can be used.
Even if he excludes the statements, prosecutors still have a strong case given that Holmes has acknowledged carrying out the attack, legal analysts say.
Holmes' statements could help prosecutors argue he was sane, said Dan Recht, a longtime Denver defense lawyer not involved in the case.
"It's the prosecution's view," Recht said, "that those statements show a degree of forethought and a degree of articulateness that are indications of a sane person and not an insane person."