ARAPAHOE COUNTY, Colo. -- There was so much blood that the theater floor had become slippery according to police officers who were the first to arrive on the scene of a massacre at the Century 16 theater in Aurora.
They were the first to testify Monday at the beginning a week sure to be full of graphic new details about the Aurora theater tragedy.
A preliminary hearing is underway for suspected shooter James Holmes. The 25-year-old is accused of killing 12 people and injuring another 58 just after midnight on July 20, 2012. He faces 166 counts of murder, attempted murder and weapons charges.
Aurora police Officer Justin Grizzle, a 13-year-veteran, wiped away tears while describing his efforts to rush badly wounded victims to the hospital in his police cruiser, including shooting victim Ashley Moser and her husband, who wanted Grizzle to turn around and head back to the theater.
"He was shot in the head somewhere. He kept asking where his ... daughter was," Grizzle said. "He opened the door and tried to jump out."
Grizzle said he had to drive and hold the man by his shoulder to keep him in the car.
The girl the man was seeking, 6-year-old Veronica Moser-Sullivan, was shot four times and was among those killed in the shooting at a midnight showing of "Batman: The Dark Knight Rises." Veronica's mother, Ashley, faces a long recovery after being paralyzed in her lower half and miscarrying after the shooting.
The scene was still gruesome when Detective Matthew Ingui arrived 12 hours later with other investigators.
"We saw the first victim laying on the ground," he said "There's shoes, blood, body tissue and popcorn on the floor."
Blood was everywhere, he said.
Ingui described how he outlined each of the victims and marked where the bodies were found. Holmes had no visible reaction during the testimony.
The detective said investigators found 209 live rounds of .223 ammunition and 15 cartridges of .40-caliber rounds inside the auditorium.
It was revealed during testimony Monday afternoon that shooting suspect James Holmes bought his movie ticket July 8. That's almost two weeks before the shooting.
Surveillance video played in the courtroom showed staff dropping to the floor and people rushing to get away from the chaos after gunfire began in Theater 9. The surveillance video was from the lobby and concession stand areas.
It also showed Holmes walking into the theater and using a ticket kiosk. Authorities say he printed out a ticket he had purchased July 8.
Det. Mathhew Ingui said a victim described Holmes as "very calm and moving with purpose."
Police Sgt. Gerald Jonsgaard said Holmes stopped the theater door from locking by using a small piece of plastic commonly used to hold tablecloths onto a picnic table. Jonsgaard also said he spotted a shotgun and a large drum magazine that appeared to be jammed on the floor of the theater.
Holmes' attorneys are expected to argue that their client has "diminished capacity," a term that, 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."
Several times, on cross-examination, they have asked witnesses about Holmes' demeanor and what he looked like when police found him.
Earlier in the day a pair of Aurora police officers who were the first to encounter the suspected gunman and the bloody massacre were the first to take the stand.
Officer Jayson Oviate and Aaron Blue said when they arrived on the scene of a reported shooting at the Century 16 theater on July 20, they encountered a sea of emotion as crowds fled the out the front of a theater where a gunman had opened fire.
In the back of the theater, Oviate described encountering what he first thought was a police officer. He soon realized it was an emotionless man who was later identified as James Holmes.
"He was wearing body armor head to toe," Oviate testified at the first day of the preliminary hearing for Holmes, which is expected to last all week. "He was very relaxed, and it was like there weren't normal emotional reactions of anything.
"He seemed very detached from it all."
Blue described his experience at the movie theater as anything but detached. After realizing calling an ambulance to the scene would be incredibly difficult in the midst of chaos, Blue began the emotional task of trying to aid victims himself.
Proceeding inside the theater, Blue described almost slipping on a trail of blood leading out of theater nine, where the attack had occurred, finding a young girl hiding behind a dumpster and caring for Jessica Ghawi, one of the 12 who died in the attack.
"I was holding her head," Blue said of Ghawi. "Every time she moved she stopped breathing."
Blue said he made four trips to the hospital, including one in which he was transporting Ashley Moser, a wounded pregnant mother who would eventually miscarry and become paralyzed as a result of her wounds.
Crying while trying to compose himself, Blue said there was a man with a head wound in the car who said he was Moser's. Blue said the man was yelling that he had to go back for his 7-year-old daughter, a girl who was later identified as Veronica Moser-Sullivan, the youngest of those slain in the attack.
Blue said the man kept trying to open the door of his squad car and jump out to return to the scene and look for the child.
Justin Grizzle was also among the officers who ferried victims to the hospital.
"There was so much blood I could hear it sloshing around in the back of my car," Grizzle testified.
One of the six victims transported to nearby hospitals by Grizzle was Caleb Medely, a stand-up comedian who fell into critical condition after being shot in the head. Grizzle described hearing a "god-awful" gurgling sound Medley mad while trying to breath.
"I shouted, 'Don't f*cking die on me," Grizzle said.
Medley, whose wife gave birth to a baby boy several days after the shooting, is the last victim who remains hospitalized. He is scheduled to be released from the hospital on Jan. 23, but he is still unable to speak and has difficulty standing on his own.
When police turned their attention to Holmes, who was described as "sweaty" and "foul smelling," Blue said the suspected gunman surrendered without a fight despite there being a semiautomatic handgun near he reach.
Shortly after officers detained him, Holmes was stripped down to his underwear. Later, he voluntarily admitted to booby trapping his apartment.
Blue said officers asked Holmes if those booby traps were rigged to explode.
"He (Holmes) said, 'If you trip them (they will explode),'" Blue said.
When asked if there was a second gunman who had aided him in the attack, Grizzle said Holmes was hauntingly coy.
"He just looked at me and smiled," Grizzle said. "It was a smirk."
The day's testimony concluded with a detective who interviewed people wounded in the attack and the two coroners who conducted the 12 autopsies.
After the hearing concludes, Arapahoe County District Judge William Sylvester will determine whether there is enough evidence for Holmes to stand trial.
CNN contributed to this report