The 56-year-old self-described "sovereign citizen" was shot by police following an hours-long stand-off at a remote property in Victoria's northeast on Monday.
He had been on the run for seven months after killing police officers Neal Thompson and Vadim de Waart-Hottart as they served a warrant related to alleged child sex offences.
Criminologist Harry Hobbs said "sovereign citizen" or "pseudolaw adherent" were umbrella terms for a broad spectrum of people who essentially did not believe the law applied to them unless they consented to it.
Freeman appeared to have been at the extreme end of that spectrum - a violent and dangerous "true believer", the University of NSW associate professor told AAP.
"The narrative that underlies pseudolaw arguments is the idea that the state has been corrupted and is now being run by wicked forces," he said.
"It's like a legal conspiracy theory. So in that sense, they always think that they're acting lawfully and acting legally."
Some social media users have been praising Freeman as a "hero" since his death, including one who likened him to bushranger Ned Kelly.
His death was being taken by some online as confirmation of their existing beliefs the government and police were out to get them, Dr Hobbs said.
"It definitely seems that some people within the broader pseudolaw community don't believe the police, and they're folding it into their previous narratives about state corruption and tyranny," he said.
"There is a risk that he will be seen within some circles as a martyr or heroic figure."
The sovereign citizen ideology is self-perpetuating in that every interaction with authority - be that police or the court system - can further frustrate and isolate those who think the system is out to get them.
Dean of law at Southern Cross University David Heilpern said Freeman was a "classic example" of someone who began by contesting a traffic offence and ended up radicalised.
"All over the fact that he refused a drug-driving test for which the maximum penalty would have been a three-month disqualification and instead he was disqualified for two years," Professor Heilpern said.
"And this is obviously one of the factors that sent him down that spiral."
Prof Heilpern said soon after Freeman killed the two police officers, several people sought to "laud or idolise" him by displaying posters of him at an anti-immigration march.
"There will be some people who now want to canonise him, I guess," he said.
Prof Heilpern said a diversion program could take others like Freeman aside before their cases progressed to help them understand where they could end up.
"Show people what happens to you if you continue to argue this crap before the courts - and that is the consequences are so much more severe," he said.
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