The detective who tried to negotiate a peaceful surrender with Melbourne's Bourke Street driver before his killing spree says he does not think the horror could have been averted.
Detective Senior Constable Murray Gentner had been enticing an agitated James Gargasoulas to surrender in the half hour before he killed six pedestrians and injured dozens more on January 20, 2017, an inquest heard.
Counsel assisting the coroner, Stephen O'Meara, asked if he thought there could have been a plan to avert the incident.
"No, I don't. I've thought about it a million times. Short of having a crystal ball, I don't," Det Sen Const Gentner said on Tuesday.
"In my belief there was always the option he was going to surrender based on my conversations with him."
Det Sen Const Gentner was trying to negotiate a peaceful arrest of Gargasoulas as police tailed him across several suburbs after he stabbed his brother.
Pursuits started, then stopped, so the plan was to wait until he got out of his stolen car to arrest him.
The detective said Gargasoulas was slowing down and seeking attention as he drove through the western suburbs.
He urged him in in a text message: "Please don't do this".
As he was being followed by police and air wing, he talked to Det Sen Const Gentner via phone and text message of killing himself, comets and bikies.
The detective said it got to the point where it didn't look as though Gargasoulas would surrender and decided to stop following him at South Melbourne.
"Certainly things changed when he noticed the air wing above him at Yarraville," he said.
"That's basically when the phone calls ended and the text messages became less cooperative with what I was trying to achieve
"My belief looking back at it all is when he went to Bourke Street was when we disengaged and he was wanting attention."
Det Sen Const Gentner defended the officers involved, in response to a police review criticising their actions as poorly coordinated and unplanned.
"We had tried to get other resources from other specialist departments in Victoria Police," he said.
"If we had the specialist resources there it would have been a well planned operation potentially. But given we didn't I can't see how we could've done anything different."
The inquest also heard a bail justice who released Gargasoulas six days before the killings was warned he would not get the mental health and drug treatment he needed if he was freed.
Police also said he posed an unacceptable risk of reoffending and had behaved dangerously in public.
Det Sen Const Gentner said he interviewed Gargasoulas after his arrest for threatening to kill a family member with a knife and found him paranoid, deluded and trying hard to impress police.
He sent an email to his superiors after Gargasoulas was bailed, saying he would work on nailing him for serious crimes so he could be remanded in the next six days, but the matter was overtaken by other priorities.
Australian Associated Press