Claims of an alternative suspect in the murder of Melbourne mum Judy Bednar are just a preposterous attempt to muddy the water, prosecutors have argued.
Mrs Bednar's son Thomas is standing trial for her murder, but the 54-year-old says he was framed.
Police discovered Mrs Bednar's naked body on the bedroom floor of her Chelsea home in May 2021.
Prosecutor Mark Rochford KC said her murder and her significant and fatal injuries had all the hallmarks of rage.
"Somebody had animosity toward her and took out their rage. It's him," he said, referring to Bednar.
"That's where all the evidence points in this case, it's what all the evidence establishes in this case."
Clothing belonging to Bednar, and found at his house, had his mother's DNA on it, jurors in the Victorian Supreme Court were told.
A palm print belonging to Bednar was found on her dresser, despite intervention orders preventing him going there.
There was also a large body of evidence that Bednar didn't like his mother for a large part of his life.
Mr Rochford said Bednar blamed his mother for reporting him to mental health authorities. He spent time in hospital as an involuntary patient in the year before Mrs Bednar's murder.
"That, we say to you, is the motive here. That's what's driven him to attack her, to express this rage and kill her," he said in closing arguments on Thursday.
Bednar's barrister John Desmond has pointed the finger at family friend Danny Cohen, in declaring his client's innocence.
But Mr Rochford accused Mr Desmond of just trying to muddy the waters.
He suggested if Mr Cohen had a falling out with Bednar he might have gone and killed him.
"Why is killing his mother going to bother (Bednar) in any way, shape or form? It's ridiculous, it's preposterous."
Mr Desmond described the murder investigation as haphazard and deficient in his closing address.
He acknowledged evidence found in Bednar's home included bloody shoes, a bloody glove and a torch but claimed those were left there in an attempt to frame him.
"Bednar's disposed of jack ... (it's) all there for anyone to collect. Is that the action of a guilty man who would just leave all that?" he asked.
"The only relevant alternative suspect who has never been searched is Cohen."
He noted Mr Cohen had also sent a text message to a friend saying Mrs Bednar died "Thursday morning" even before police knew what day she had died.
Mr Cohen, who appeared as a witness in the trial, denied he killed Mrs Bednar and framed her son.
But Mr Desmond said his credibility was in dispute and his evidence required close scrutiny.
"We say it would be dangerous to accept the evidence of Danny Cohen," Mr Desmond said.
He described Bendar as being in the fight of his life.
Mr Desmond's closing address will continue on Friday. Jurors are expected to begin deliberating on Monday.
