Barry Stewart owed $287.

Rather than pay the fine, he chose to spend three days in the Edmonton Remand Centre.

He never left.

Two days into his sentence, in the small hours of the morning, he was stomped to death by a fellow inmate, a mentally ill man he should not have shared a cell with.

There were two inmates in tank 10 on morning of May 12, 2011, but there was only one mattress, said Robert Andraidt, deputy director with the Solicitor General's department.

"We had so many individuals in that centre, it was difficult at times to find a mattress," Andraidt told a fatality inquiry on Monday.

Stewart had been there as a prisoner since May 10, when he was arrested for failure to pay an outstanding fine.

He had been cited earlier for not being able to produce an LRT ticket. When he was picked up, he was given the choice to pay the $287 fine or spend three days in custody.

He chose custody, and was put into a cell with Justin Somers, an inmate with mental health problems.

Both were being housed temporarily in holding tank 10, in the admissions and discharge area, where they were awaiting placement in other units. At the time of the killing, sources told CBC News that psychologists assessed Somers and recommended he be kept apart from other inmates.

Both men were scheduled to be transferred to 5-C, the mental health unit. But 5-C was full.

At 4:42 a.m., in a scene captured by a video camera, Somers stomped Stewart to death by jumping on his head 26 times. The attack lasted eight minutes.

That videotape was entered as evidence Monday at the inquiry.

Medical examiner Dr. Graeme Dowling said the victim, who was 5-foot-11 and weighed 137 pounds, died from "catastrophic head injuries."

During the attack, Stewart's right ear "was almost torn away from the scalp," he said.

Both sides of his lower jaw were broken. Even the base of the skull was fractured.

"He died of a crush injury of the head," Dowling said. "Almost like the head is in a vise, being crushed."

Somers initially jumped from a bench onto the victim's head. Dowling said Stewart's skull was likely fractured with that first blow.

Asked if Stewart could have survived had guards intervened, he said: "My sense was with the initial assault, probably the lethal injury had taken place."

Somers, who was 27 at the time of the attack, was charged with second-degree murder, but was found not criminally responsible in 2013.

Edmonton's old downtown remand centre, where Stewart died, often housed up to 800 inmates, Andraidt said. The new centre, opened recently in the north-end, can now hold 1,300.

Andraidt said unit 5-C in the old remand centre had only 12 cells. The mental health unit at the new facility has 36 cells, with capacity for 72 inmates.

At the old centre, psychologists only worked day shifts. They now work in two shifts, mornings and afternoons.

"Unfortunately at this time, we still do house some mental health inmates in admissions and discharge, because there aren't enough mental health spaces," Andraidt said. "Even with the new remand centre."

Inquiry lawyer Mona Duckett asked what more is being done now to make sure these inmates are being seen by psychologists once every shift.

"I know for a fact they are doing their rounds, they are seeing these individuals," Andraidt said. "There is documentation being done."

The inquiry is scheduled to last until Friday.