Jurors in the trial of the father and son charged with the murder of a teen runaway from Abbotsford pored over pictures of the young girl's remains in Chilliwack Supreme Court on Tuesday.

The court examined pictures showing a blue zippered bag holding theskeletal remains of 14-year-old Chelsey Acorn's body after it was found in a shallow grave in April 2006 by hikers in remote area outside of Hope.

Truckers Jesse Blue West, 56, and his son, Dustin Blue Robert Moir, 24, have both pleaded not guilty in the case.

Forensic pathologist David Charlesworth testified that Acorn's body was in a medium or advanced state of decomposition when it was found and the autopsy conducted.

No clothing, jewelry, or evidence of foreign materials like bullets or other metals were found. However, the left side of the skull had a large fracture above the eye socket.

"It was very significant trauma ... a caving in of the front of the head. That trauma would or could be the cause of death, if that was the only injury," said Charlesworth.

He estimated the body had been in the ground four at least four months.

Acorn had gone missing from an Abbotsford-area ministry group home in June 2005.

In opening statements Monday, Crown outlined how both Moir and West confessed key details of the murder to a "crime boss" during an elaborate undercover police operation.

Investigators held back key evidence only killers would know, including the fact Acorn was not clothed when buried, and her skull was crushed.

Moir allegedly told an undercover officer his father had strangled Acorn from behind, and he later completed the job from the front.

He said they put the girl in the grave, and he crushed her head with a rock to ensure she was dead.

On a separate occasion, West told another undercover operator he had "cracked" Acorn's neck from behind, stripped her naked, put her in the grave and dropped a rock on her head.

Both men also talked about disposing of Acorn's clothes.

West's defence lawyer, Richard Fowler, asked Charlesworth to confirm he hadn't discovered any significant or identifiable trauma to the neck area of the victim during the autopsy.

Fowler also asked the forensic pathologist to agree, that given the decomposition of the body, it wasn't possible to determine if Acorn's death had been caused by strangulation or asphyxiation.

Charlesworth was also cross-examined by Moir's lawyer Dan Henderson, who asked the doctor to attest he'd be unable to tell if Acorn was already dead when she received the head fracture.

Though some details provided to undercover officers by both accused differed, both had key information about Acorn’s death, argued Crown prosecutor John Hempstead.

The pair were arrested in a final meeting with the undercover officers in March 2007.

While being transported in a police van equipped with a recording mike, the pair discussed their situation. Their conversation "speaks volumes," said Hempstead.

He said neither expressed any remorse for the victim, and Moir pleaded with his father to take more responsibility for the crime because "he was younger and had his whole life ahead of him."

Police believe Acorn was killed in the fall of 2005 soon after reports she was spotted in Abbotsford, Mission, Surrey and Chilliwack dried up.

West, from Victoria, and Moir, who formerly lived in Abbotsford, Surrey and Whislter, were long-haul truckers who sometimes worked together.

The trial continues Wednesday and is expected to last into January.