James Holmes is accused of killing 12 people and injuring more than 50 (Reuters)
James Holmes is accused of killing 12 people and injuring more than 50 (Reuters)Reuters

Survivors of the Aurora massacre have been reliving their ordeal on the fourth day of the trial of gunman James Holmes.

On 20 July 2012, the 27-year-old walked into the midnight screening of The Dark Knight Rises in a cinema in the Denver suburb of Aurora, armed with guns and ammunition, wearing a gas mark and body armour. He shot into the crowd indiscriminately, killing 12 people and injuring 70 others. The youngest victim of the massacre was six-year-old Veronica Moser-Sullivan, who died.

Holmes has admitted to the shootings, but is pleading not guilty by reason of insanity. His lawyers are arguing that he suffers from schizophrenia which compelled him to kill.

Giving their testimony, witnesses described the scene of carnage the gunman left in his wake as akin to a "horror film."

Aurora Fire Department Lieutenant Bernd Hoefler told the court how he encountered a scene of "blood and bodies everywhere".

"Some were trampled. Some had missing parts of their head. It was like a horror film," he said.

Police officer Annette Brook told jurors: "It was dim, the movie was still playing, the alarm was going off. I began to notice the bodies, the live victims, the blood."

Joshua Nowlan was one of the victims of the shooting. The father of two, who went to see the movie with two friends, said the gunfire started 20 minutes into the film.

He was shot twice as he shielded his friends from the gunfire and was left with a bloody, gaping hole in his leg. He described the excurciating pain as his friend tried to push the muscle and tissue back into his leg. "It felt as if someone was taking a rusted railroad nail and jamming it into my leg," he told the court.

Mr Nowlan, who has undergone multiple surgeries and now walks with a stick, recalled seeing the gunman scouring the scene for more victims, as he went on his shooting rampage.

"I can see him with the gun holding up to his chest and he was pointing down to the ground looking for other people."

The police officer who arrested Holmes told the court the suspect displayed no emotion after the shooting.

Officer Jason Oviatt told the jury of 19 women and five men that the former neuroscience graduate seemed "very relaxed" when he found him standing beside a car behind the movie theatre.

"He was sort of vacant. He was very relaxed, he was very calm and sort of disconnected. Not displaying any outward emotion or any outward sign of real engagement in what's going on. He was very sweaty. He smelled bad," Mr Oviatt said.

Mr Oviatt revealed that Holmes answered questions from officers clearly and coherently. When asked if he had an accomplice he replied: "It's just me."

Tethered to the floor by a harness beneath his blue pin-striped shirt, Holmes listened without emotion as the prosecution presented the graphic detailed accounts of witness.

Holmes faces 165 criminal counts, including murder and attempted murder, in one of the deadliest mass shootings in American history.

He has pleaded not guilty to all charges by reason of insanity. However, prosecutors are contesting his plea, saying he carried out the attack "to make himself feel better" because he had lost his career, girlfriend and purpose in life. They will push for the death penalty if they can prove he was sane at the time of committing the crime.