A man who shot dead his mother and brother after a years-long family dispute is arguing he was mentally impaired at the time of the killings.
Paul Cohrs is on trial in the Victorian Supreme Court, charged with the murder of his 81-year-old mother Bette Schulz Cohrs.
He shot her in the chest at her Red Cliffs home in Victoria's northwest on October 30, 2018, an hour after killing his brother Raymond in a nearby NSW town, a jury was told.
Cohrs is not facing another count of murder over his brother's death because it was in a different jurisdiction, but his defence barrister Lucien Richter said there was no dispute over the shootings.
"Paul Cohrs killed Betty Cohrs and Raymond Cohrs - he did it," he told the jury on Friday afternoon.
"But there's one final thing before we slam the door on the issue and, in simple terms, it's whether he was in his right mind."
The jury was told the relationship between Cohrs and his brother Raymond became strained in 2012 as they had conflicting ideas over the family business.
That escalated to civil court proceedings in 2016, as Raymond accused his brother of using the business' money for personal expenses.
In turn, Cohrs claimed his brother was trying to take his money and it was having a detrimental effect on his health.
He also accused Raymond of killing their father, even though the man died by suicide in 1984, the jury was told.
Raymond, who had the support of his mother Bette, decided in 2018 to get appraisals on a number of properties connected to the family business.
That included a Lake Victoria Station property over the border in NSW that Cohrs and his wife were living in.
On October 30, 2018, Raymond and a real estate agent went to the property for the evaluation and were met at the gate by Cohrs, who called his brother a "liar and a thief".
The men drove to the shearing shed and once Raymond was out of the vehicle, Cohrs grabbed his shotgun and fired two rounds into his brother, the jury was told.
He approached Raymond who was lying on the ground, asked him what it was like to feel pain, before shooting him again in the head and chest.
Cohrs told the real estate agent he wasn't going to hurt him but handcuffed him and left him in the shed before saying his brother deserved it.
Cohrs then drove about 120km to his mother's property in Red Cliffs, near Mildura.
He entered the kitchen where his mother was standing and fired a single shot into her chest.
Cohrs left the scene and reported her death to a local police station before driving back to Lake Victoria Station where he freed the agent and attempted to kill himself.
Police arrived and arrested Cohrs, who expressed shock at surviving and told officers jail was his worst nightmare.
Mr Richter told the court Cohrs had delusional disorder and a psychiatrist had found he was not of sound mind at the time of the killings.
He urged the jury to find Cohrs not guilty on the basis of mental impairment as he could not have understood his actions were wrong.
But prosecutor Melissa Mahady said a separate psychiatrist had found Cohrs did have the mental capacity to comprehend what he had done.
The trial before Justice Lesley Taylor continues.
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