EDMONTON - Young Nina Courtepatte met her lonely, late-night end on an Edmonton golf course by absorbing 15 head blows so grievous, they caved in her skull, damaged her brain, exposed bone, broke her jaw and knocked her teeth out of alignment.

"If I look at the totality of the injuries and look at the injuries to the right side of the head and brain, I don't believe it would be a survivable injury,'' medical examiner Dr. Graeme Dowling testified Tuesday at the first-degree murder trial of Joseph Laboucan and Michael Briscoe.

Laboucan, 21, of Fort St. John, B.C., and Briscoe, 36, of Edmonton are charged with first-degree murder in the April 3, 2005, death of 13-year-old Nina.

They are accused of being part of a group that randomly targeted and picked up Nina and a friend at West Edmonton Mall that fateful spring night and drove them to a deserted west-end golf course on the pretense of going to a party.

Once there -- according to witnesses who have testified at the Court of Queen's Bench trial -- Nina was struck with a wrench, then raped by Laboucan and another man while others held her down. They then tried to stab her with a dull blade and, while she begged for her life, bludgeoned her with a sledgehammer.

Dowling performed the autopsy on the five foot three inches tall, 112-pound girl two days after her body was located on the fourth fairway of the golf course. She was found face up near a patch of grass stained deep red. One of her shoes lay nearby.

"She was quite small and had a slight build,'' said Dowling, Alberta's chief medical examiner.

He testified Nina's head was split open 15 times due to blunt force trauma.

"There was one area on the right side of the skull measuring four inches across that was caved or pushed in,'' he said.

The blows would have rendered Nina unconscious almost immediately, he said, adding that even if she had received immediate medical treatment, she would likely not have survived.

He said there was a shallow stab wound on the lower side of her jaw and two cuts on the neck so superficial they barely pierced the skin.

Dowling also said there were no external or internal injuries to her pelvic region or genitalia.

The Crown prosecutor asked if Nina's injuries could have been caused by punching.

"In terms of fists, that's highly unlikely,'' he replied, but said he couldn't rule out the possibility someone kicking her with shoes on could have inflicted the blunt force damage.

There were marks on Nina's hands and forearms consistent with her trying to defend herself from attack, he said.

On Monday, a woman who was in the group at the golf course admitted she hit Nina with a wrench and pinned the girl's arms to the ground while Laboucan raped her.

But she said on a police tape she did it because earlier that day Laboucan had threatened to "hurt'' her if she didn't do as he instructed.

An RCMP DNA expert has testified he can't rule out that semen stains found on Nina's jeans belonged to Laboucan.

The trial has also heard that Briscoe told police he watched the violation and brutalization of Nina but otherwise only drove the car. He fingered Laboucan as the ringleader and said Laboucan talked before the crime about picking someone at random and committing murder.

The two accused showed little emotion Tuesday as they watched the proceedings from opposite ends of the prisoners' dock.