Norman Cheney.
Norman Cheney.

Prosecutor: Mental illness did not make Cheney a demon

THE world of drugs, infidelity and violence surrounding the gunshot that killed Norman Cheney should not cloud the assessment of the man accused of pulling the trigger, a jury has been told.

Crown prosecutor Todd Fuller said Mr Cheney, 41, might have been demonised throughout the trial for his violent outbursts but he had a mental illness.

"That doesn't make him a demon; that doesn't make him some sort of monster," he said.

Anthony Charles Oliver, 38, has pleaded not guilty in Brisbane Supreme Court to murdering his mate, while he was having an affair with Mr Cheney's wife Trichelle Cheney.

He claims Mr Cheney learned of the affair, bashed him, poured petrol on him and was about to set him alight when he shot him in self defence.

Mr Fuller, in his closing address, said the jury must look at the "relationships and interrelationships, mostly between this man with Trichelle and with Norm" to assess where the truth lay.

"It's the three of them that caused the events of December 20, 2010, and their interactions with each other," he said.

"This trial is about whether this man was justified in doing what he did to Norm Cheney

"But there are limits..."

Mr Fuller said Mr Oliver must have had a reasonable apprehension of death or grievous bodily harm to use "lethal force" to defend himself.

"I'm not going to suggest to you that there was a pre-plan in this man's mind to kill Norman Cheney that day, that he drove him into some isolated spot, pulled out a gun and just shot him in the back of the head," he said.

But Mr Fuller questioned what kind of friend would take his mate to get illicit drugs to mix with his bi-polar medication.

He asked what kind of friend would sleep with his mate's wife for about three years behind his back.

Defence barrister Michael Byrne said the prosecution had not excluded self-defence beyond reasonable doubt.

He said the jury must assess Mr Oliver's testimony like any other witness and check if his evidence "stacks up against other things we know about Norm Cheney".

"(Mr Oliver's) the only person who can give an actual account of what did happen in that car," he said.

"He has given clear, sometimes emotional, evidence of how and why he caused the death of his mate."

Mr Byrne said there were moments the jury could be sure of his client's truthfulness.

He spoke of pathologist Nathan Milne's testimony that the sharp cut on Mr Cheney's throat was likely caused by a knife but he could not rule out the edge of the barrel caused it.

Mr Oliver said he did not believe the barrel had caused the injury when he was shoving Mr Cheney into it at Esk.

"He chose not to conveniently fit the evidence of Dr Milne (into his story), which he could have easily done," Mr Byrne said.

The jury is expected to begin deliberating on Thursday.