It had fallen to Acting Sergeant Nathan Macklin to get through to the man now lying slathered in his own blood, having sliced off his own pinky finger with a kitchen knife.
"Mate, we're the police, we're here to help you. You need to get rid of that knife," the police officer said through a window of the Waramanga home on October 31, 2017.
It was a confronting scene, he told an inquest into the death of 54-year-old Anthony Caristo on Friday. The room was doused in Mr Caristo's blood, windows were shattered, police colleagues said the man had earlier been frothing at the mouth and had so far been unresponsive to their approaches.
"Mr Caristo just started staring at me, his eyes were fully focused on me but he still had that knife. It was a thousand-yard stare like I've never seen before, like I wasn't there," Sergeant Macklin said. It was like talking to a brick wall, he said.
Shock from blood loss, the effects of drugs or alcohol, psychosis: many things ran through the officer's mind for why Mr Caristo was acting the way he was.
But the officer believed he had no other option but to draw out his Taser. That crystalised in his mind when through the window he saw Mr Caristo raise his right arm and with full force and an overhead swing plunge the knife toward his leg before it bounced back up. Sergeant Macklin said he could hear the knife's impact and that it was like how someone would cut their own leg off.
"I think that somewhat startled me," Sergeant Macklin said, remembering thinking: "This is just crazy.
"That he's going to kill himself.
"That essentially I had two options: I either Taser him to stop him harming himself, or I stand and watch."
Sergeant Macklin, who was only there because he had agreed to cover a colleague's shift for an hour or so while he went to a meeting that day, shot a Taser cartridge toward Mr Caristo.
The prongs lodged into his body and Mr Caristo began to spasm, leading the police officer to believe it had worked.
He explained that Tasers when fired and lodged properly can disrupt a person's voluntary control of their muscles for the five seconds that the charge lasts. He said that can immobilise the person and allow police to gain control.
But Mr Caristo died at the scene.
An autopsy found very high levels of methamphetamine in Mr Caristo's blood and moderately advanced heart disease.
The report found that in the absence of other features, Professor Johan Duflou would be willing to state the cause of death as a drug overdose.
However, he concluded the cause of death to be cardiac arrest after using methamphetamine and being subjected to the electric shock of the Taser.
When Sergeant Macklin was asked by counsel assisting the Coroner, Ken Archer, what he understood the philosophy behind the Taser to be, he said: "The only reason we carry Tasers is to give us one more option to avoid the use of lethal force."
Sergeant Macklin said he had already ruled out pulling his firearm, ruled out capsicum spray because it would contaminate the area preventing paramedics access to help Mr Caristo and risked causing a panic response, and ruled out the baton because it would require police to get in close proximity to the man still holding a knife.
The inquest heard Sergeant Macklin was qualified to carry a Taser in January of that year and was one of a small number to be selected as a trainer in the use of the weapon. He had only deployed a Taser in one other instance, a few days earlier.
The inquest will continue at a date yet to be listed.