SUPREME COURT: Fracture 'rapidly and inevitably fatal'
A FORENSIC pathologist has told a jury in the Supreme Court murder trial of Donald Gordon that he does not believe the victim's fatal wounds were caused by a car tyre.
Gordon has previously pleaded guilty to manslaughter, after admitting to running over his friend with his car in November 2013 while both men were heavily intoxicated.
He is facing a charge of murder based on the crown's case that Cotter's fatal injuries were inflicted by a large, blood-stained rock found near his body.
Yesterday, in the trial's sixth day in the Grafton courthouse, the question of whether it was a rock, tyre, or the undercarriage of a vehicle that caused the victim's death was the main focus of proceedings.
The jury heard from forensic pathologist Timothy Lyons, who performed a post-mortem on Cotter following the discovery of his body at Collum Collum station to "paint a picture" of how his injuries might have occurred.
During questioning by the crown, Prof Lyons determined that in Cotter's case the cause of death was blunt force head trauma.
In particular, it was a transverse skull fracture that was described by the pathologist as "rapidly and inevitably fatal".
But the court also heard the swelling of Cotter's brain examined in the post-mortem suggested his death was not immediate, although Prof Lyons said it was likely he was rendered unconscious by the blow.
"I think that the nature of the injury is such that he may have had some basic functions but I don't believe he would have been conscious," he said.
Prof Lyons said he believed it would take a severe application of force to cause such an injury.
Using his knowledge of a large blood-stained rock found near the body, and the presence of Cotter's tissue and hair found on the undercarriage of Gordon's Mitsubishi Magna, the pathologist said it was unlikely the rock alone could have caused the injury patterns seen on Cotter's body. Other injuries to the victim's legs and torso were mostly abrasions and lacerations, consistent with being dragged under a vehicle or otherwise.
Prof Lyons also said he believed a downward force from the rock could have caused the main skull fracture and other injuries seen on both sides of Cotter's head, saying it was "a similar pattern to someone being stomped by a pair of boots".
"I believe there has been more than one application of force to cause a pattern of injury to the head," he told the court.
In cross-examination, public defender Jason Watts implied the fatal injuries could have been sustained by a vehicle tyre, citing new evidence of trace DNA found on the front passenger-side mudguard of the Magna.
He offered the theory that there was firm evidence to assume the wheel had gone over the body and flicked DNA onto the mudguard.
But Prof Lyons rejected that implication, saying there were numerous ways the DNA could have ended up where it did.
"I remain of the opinion a car tyre did not go over the head," he said.
The cross-examination of Prof Lyons continues today.