A dinner gathering in Canberra's south descended into chaos when a man discharged from a mental health unit a few hours earlier stabbed a guest in the chest, creating a wound about 15 centimetres deep.
But Tuggeranong resident Russell Te-Rangi Walker claims he did not intend to kill the victim, and that even if a judge finds he did, he should be acquitted on grounds of mental impairment.
The judge-alone trial of Walker, who has pleaded not guilty to attempted murder and an alternative count of intentionally inflicting grievous bodily harm, began in the ACT Supreme Court on Wednesday.
Agreed facts tendered to the court show Walker and the victim were among guests at the Bonython home of Walker's "intermittent" partner on the evening in question in June 2019.
Not long after the victim arrived, he began to feel that Walker was looking at him "all funny".
"[Walker] said something like he thought [the victim] was trying to take away his family," the agreed facts state.
Later that evening, Walker asked the victim to follow him into a bedroom, where the then-29-year-old pushed the tip of a knife against the victim's chest and threatened him.
Walker's partner intervened and things briefly calmed down, but tensions rose again after the gathering moved outside to a patio area.
The victim was sitting in a chair when Walker admits he stood up and moved around the other guests and a table to plunge a knife into the victim's upper chest.
As blood began to gush from the wound, Walker pulled the knife out and exclaimed, "Oh my God, I've stabbed him! Oh my God, my God."
He then called triple zero and cried out for help, alerting a neighbour who came to see what was going on.
The victim ultimately underwent life-saving surgery, while Walker was arrested and remanded in custody.
Prosecutor Rebecca Christensen argued in court on Wednesday that Walker had intended to kill the victim.
She pointed to factors including that Walker had stabbed the man in "the heart area" using what she described as a large knife.
Ms Christensen also said the victim had described Walker having whispered threats like "you're dead" moments before the attack.
"He was intent on causing the death of [the victim]," she said.
But defence barrister Jon White SC disagreed, saying there was "no obvious reason at all" for Walker to have wanted the victim dead.
He highlighted that there was only one stab wound, saying Walker could "easily" have continued his attack and killed the victim if he had wanted to.
"There would have been other ways to more efficiently kill the victim," Mr White said. "That's the reality of it."
He also said Walker had been "clearly shocked by his conduct", having "immediately tried to summon aid".
Aside from Walker's intent, the other key issue in his trial is his mental health.
Ms Christensen said the Crown did not agree to special verdicts of not guilty by reason of mental impairment.
But she did not detail why, saying it was for Justice David Mossop to determine on the available evidence.
Mr White submitted that such verdicts should be entered because, based on the evidence, the judge would have "nowhere else to go".
The court heard Walker had been diagnosed with schizophrenia, and that during his time on remand it had become apparent that "he suffers from paranoid delusions [and] hears voices".
The agreed facts also detail how Walker was detained under the Mental Health Act and taken to Canberra Hospital the day before the stabbing.
He was initially examined in the emergency department following incidents that included him expressing suicidal ideation and talking about how he believed "commandos" were coming to get him.
Walker was transferred to the adult mental health unit early on the morning of the stabbing, but released that afternoon after a psychiatrist deemed him "OK for discharge".
Justice Mossop said on Wednesday that he would give his verdicts in the trial on Thursday afternoon.
