Will Australia's terror threat change?

Australia's terror threat is currently at 'possible', the second lowest.

"The Bondi stabbing may impact the threat level because of the targeting of women in that attack and the fact that there was mass violence, even if it doesn't fit with the current terrorist definition," she said.

Prof Corner said the Australian government's definition of terrorism includes "religiously motivated extremist or ideology motivated extremism".

Incidents declared terror events since 2014:

Prof Corner said "the way that terrorist attacks are designated in Australia is due evidence of ideation...religious or political, and evidence there is some kind of preparation for the attack."

But recent research suggests "the line between personal grievances and political ideology can be quite blurred".

The public statements from the police suggested that the attack on the bishop involved some pre-planning and forethought, she said.

Prof Corner said the western Sydney attack fitted with similar types of terrorist attacks that had become more prevalent in Australia over the last decade.

These attacks are marked by low level weaponry such as a knife or a car instead of an explosive device, take place in a public space and usually involve an offender "acting alone".

The most infamous examples of these attacks include the 2014 Sydney Lindt siege where two victims plus the perpetrator died.

But Prof Corner cautioned against the idea that offenders act completely alone, with the pattern suggesting "people are not alone and in some way are supported by others".

"Research suggest they [terrorist offenders] are not as lonely as we think they are, and they are often connected to other radicals through formal groups or speaking to people online... the nature of the internet means that people are never truly alone" she said.

Prof Corner said there was also a concern that people were being radicalised younger than before.

"We have seen that people who have come to the attention of services have been substantially younger than we expect them to be," she said.