James Holmes sat in the interrogation room in his T-shirt, white socks and boxers.

Gone was the body armor that police found him wearing when they encountered him outside a movie theater where scores of people had been shot. Police had cut it off.

Craig Appel -- the lead detective in the investigation into the 12 killings at the Century Aurora 16 Multiplex Theater in Aurora, Colorado -- testified Tuesday that paper bags had been placed over Holmes' hands to potentially preserve evidence. As Holmes was being interviewed, he used the paper bags as puppets.

He played with his polystyrene drinking cup as if it were a piece in a game. Appel said

He removed a staple from the table and tried to stick it in an electrical outlet, the detective testified.

Asked by a defense attorney whether he had ordered a blood test for Holmes, Appel said he had not.

"There were no indications that he was under the influence of anything," he said.

Appel testified that investigators found 76 shell casings at the auditorium where Holmes is accused of killing 12 people and wounding 58 more on July 20, at a midnight movie showing. Most of the spent rounds -- 65 -- were .223 caliber, while six were shotgun shells and five were .40 caliber.

Aurora police Sgt. Matthew Fyles testified the .223 cartridges were steel-core rounds, which are more likely to pass through a body intact and can cause multiple wounds.

The details came on the second day of Holmes' preliminary hearing, which could last all week. It is meant to prove to Arapahoe County District Judge William Sylvester that prosecutors have enough evidence to proceed to trial.

Attorneys for Holmes, a 25-year-old former neuroscience graduate student at a nearby university, are expected to seek a "diminished capacity" defense that could prevent the case from getting that far. Some of their questions during cross-examination have also suggested they are trying to make it appear Holmes might have been under the influence of something the night be was arrested.

The term "diminished capacity," according to the Colorado Bar Association, relates to a person's ability or inability "to make adequately considered decisions" regarding his or her legal representation because of "mental impairment or for some other reason."

The day wrapped up with Fyles, who detailed what happened to each of the victims, including a dozen people who were injured as people tried to flee.

Fyles will testify again Wednesday morning as the last prosecution witness. The defense is allowed to call two witnesses.

Chilling 911 calls played

Also Tuesday, prosecutors played the first 911 calls from the movie theater shooting as they continued building their case at a preliminary hearing.

The recording was loud, chaotic and difficult to understand. There was too much sound to make out what the caller was saying.

Just one thing is unmistakable: the sound of gunshots. At least 30 of them. In 27 seconds.

Detective Randy Hansen testified that the first call to authorities came 18 minutes after the film started. More trickled in until the torrent was complete: 41 calls in all, he said.

Because the movie was still playing and, in at least one, the gunman was still stalking the theater, the calls are difficult to make out. In one, a 13-year-old girl called to say her cousins had been shot. A 911 operator tried to lead the sobbing girl through performing CPR on one who was still breathing.