Brendan Nugent held delusions of being persecuted and was most likely in a state of psychosis when he allegedly attacked Helen Haines according an early prison assessment by authorities.
But there are no signs to date that he was influenced by extremism, the ABC reports, although investigators had not ruled out a personal grievance.
Mr Nugent has been charged with dangerous driving causing serious injury, intentionally causing serious injury, and the Commonwealth offence of causing harm to a Commonwealth public official.
He appeared before Wangaratta Magistrates’ Court on 21 October, where no plea was entered.
According to the ABC report, a source said the initial Victorian prisons assessment suggested that he had a “significant mental health disorder” and schizophrenia was being explored as an possibility.
“So far nothing is indicating extremism,” the source said.
“There’s no group, no ideology, no intention.”
While media reports had focused on his social media postings on Israel, Gaza, climate change and pedophile Jeffrey Epstein there was nothing to link these views to the incident to date.
“His posts online are like symptoms of an illness getting worse. When someone’s mental health is sliding, the conspiracy thinking gets louder and more frantic,” the source said.
“Persecutory beliefs are the most common kind of delusion, and they often latch onto whatever in the news. So you see Ukraine and the CIA turning up alongside fears about his own safety.”
However, given Ms Haines was a long-term friend of Mr Nugent’s stepmother, a personal grievance had not been ruled out.
“She’d been a friend of his family for more than 20 years, and she was his local member. That’s not a random choice. “When paranoia takes hold, it usually pulls in the people around you,” the source said.
Helen Haines lost both legs after the alleged attack outside her Wangaratta electorate office.
She is recovering in a Melbourne hospital where she remains in a serious but stable condition where her husband Phil and family are caring for her.
Victoria Police Chief Commissioner Mike Bush previously said there was no intelligence against Mr Nugent prior to the alleged deliberate attack.
“We had no intelligence holdings against this 43-year-old individual, and there was nothing known to us that would have arisen or piqued our interest or given any indication that he was an immediate threat,” he said.
He said while there was no “direct evidence” available, he would investigate the alleged offender’s potential links to the sovereign citizen movement.
“That’s obviously something we’re exploring. We haven’t had any direct evidence of that,” he said.
“Like everyone, we’re examining social media associations, talking to witnesses, friends and colleagues.”
Australian Federal Police Commissioner Krissy Barrett also said her agency had no dealings with the accused.
“What I can say is we didn’t have any specific intelligence that would have indicated something as atrocious as happened,” she said.
However, she said teams were “charging almost one individual every week for targeting Commonwealth parliamentarians or high office holders”.
“It is one of our biggest parts of the business, and we have extensive resources dedicated to that work. That includes our national security investigations team,” she said.
“We are not only charging offenders where they have committed offences, but we are also intervening early where we see escalating or concerning behaviour.”
Victorian Premier Ben Carroll said the alleged attack on Dr Haines “calls for some soul searching”.
“Online propaganda is turning neighbour against neighbour. And it’s bloody frightening,” he said.
“I’m not saying everyone should agree on everything … we must all be free to speak our minds. But that freedom comes with obligations: respect for the law, respect for each other, respect for leaders, respect generally.”