CENTENNIAL — To this day, the image of a dying little girl haunts Aurora police officer Justin Grizzle.

On Thursday, as he testified in the Aurora theater shooting trial, he recalled the anguish he felt when he had to leave Veronica Moser’s little body on the Century 16 movie theater floor and rush to the next victim.

“I had to step over her because I knew she was gone,” Grizzle said, struggling with tears. He called it the most difficult thing he had to do that night.

Later, Grizzle would drive the girl’s mother, Ashley Moser, and her boyfriend Jamison Toews to the hospital. Moser was unresponsive with gunshot wounds to her chest. Toews kept screaming that their daughter had been left behind and tried to jump out of the speeding police car.

Grizzle grabbed his shirt with one hand as he steered with the other.

“That’s when it hit me that the little girl I had walked over was their’s,” Grizzle said. “I wanted to tell the man, ‘She’s gone. She’s gone.’ But I couldn’t.”

Grizzle was one of six Aurora Police Department officers to testify during the fourth day of the trial. The defendant, James Holmes, is charged with 12 counts of murder and 70 counts of attempted murder in the case. He has admitted to the massacre but has pleaded not guilty by reason of insanity. He could face the death penalty if convicted.

DOCUMENTS: See diagrams of theater and where some victims sat.

The jury saw an emotional side of police officers rarely seen in public. The uniformed men and women are trained to remain stoic and matter-of-fact, but several have cried as they relived July 20, 2012 from the witness stand.

“It was horrendous,” Grizzle said. “It was a nightmare. It looked like a war zone.”

Officers who testified Thursday were among the first on the scene, and two spoke of following a trail of blood in the back of the theater that led them to Holmes, who was standing by his car with his hands resting on the roof.

And Thursday was the first day the defense team asked questions of witnesses, mostly focusing on police response times and Holmes’ demeanor during his arrest.

The day’s testimony closed on a grim note as Aurora Detective Matthew Ingui showed pictures of 10 bodies lying on the theater floor. Most victims and their families had cleared the courtroom for Ingui’s testimony, although a few tried to endure it.

When Ingui showed the picture of Micayla Medek, her grandmother Marlene Knobbe sobbed aloud before muffling the sound in a tissue and running out of the room.

More victims heard Grizzle’s testimony. Although Grizzle has testified in previous hearings, the powerful images still caused witnesses and jurors to wipe away tears.

Caleb Medley and his wife, Katie Medley, were in the courtroom as Grizzle told about rushing Caleb Medley to the hospital during a third trip to the hospital.

Medley had been shot in the face and was choking on his own blood.

“He made some of the most awful noises I’ve ever heard,” Grizzle said. “I could tell he was dying.”

But Grizzle repeatedly yelled, “Don’t you (expletive) die on me!” as they sped toward the hospital. Caleb Medley, who is in a wheelchair now and can barely speak, sometimes nodded his head as Grizzle spoke.

Police officers transported victims in their patrol cars because ambulances could not get through the crowded parking lot to the back of the theater where some of the most serious victims were carried.

Sgt. Stephen Redfearn told of his frustration as he tried 10 times to find an ambulance to respond. He consulted with Grizzle and decided to start loading victims in patrol cars because, “quite honestly, out of desperation in what I thought was people passing right in front of our eyes.”

Redfearn had also been a part of Holmes’ arrest.

The first two officers to find the suspect were patrolmen Jason Oviatt and Jason Sweeney. They came across two wounded and bleeding shooting victims on a sidewalk as they approached the theater. They followed their trail of blood in hopes of finding a back entrance.

They came across a person standing behind a white car and dressed in black in what first appeared to be police SWAT gear. Both officers said they first thought Holmes was another cop.

But he was too calm, and as they got closer they realized his gear was not department-issue, both officers testified.

“Everybody was urgently doing something,” Oviatt said. “This person was very relaxed standing by the car and wasn’t doing anything at all.

“I knew he had to be involved in the shooting.”

Oviatt and Sweeney pointed their guns and ordered Holmes on the ground. They pulled two knives and a loaded gun magazine out of his pockets.

When asked if there were other shooters, Holmes replied, “It’s just me,” Sweeney said.

After officers put Holmes in the back of Redfearn’s patrol car, he started fidgeting and moving around.

Police officer Aaron Blue asked Holmes if he had any weapons.

“He answered with, ‘I have four guns and I have improvised explosive devices at my house and they won’t go off unless you set them off,” Blue said.

Officers feared Holmes might have additional weapons tucked under his body armor so they pulled him out of the car and stripped him of his gear and clothes. He sat in the patrol car in his T-shirt and underwear.

Redfearn called narcotics detectives to ask them to check Holmes’ Paris Street apartment.

Holmes cooperated with police. Officers told the jury that he watched the chaos unfold around the theater as he waited to be driven to police headquarters.

When asked to describe Holmes, Oviatt said, “He was sort of vacant. He was very relaxed. He was calm and sort of disconnected.”

As for Holmes’ physical appearance, Oviatt, who stared down the defendant when asked to identify him, said, “He was very sweaty. Smelled bad.”

Noelle Phillips: 303-954-1661, nphillips@denverpost.com or twitter.com/Noelle_Phillips