A decade on from the shocking slaying of an unarmed police officer, a state's top terrorism cop admits tracking down radicalised people is harder than ever.
NSW officers on Thursday recalled the life of police accountant Curtis Cheng, who was gunned down by a radicalised teenager on October 2, 2015.
The assailant - 15-year-old Farhad Mohammad - was subsequently killed in an ensuing gunfight with guards outside the NSW Police Force headquarters.
Deputy Commissioner David Hudson, the state's lead anti-terrorism officer, used the 10-year anniversary to reflect on the changing extremist threat in the past decade.
While police were focused on ISIS and al-Qaeda in 2015, Mr Hudson said the "threat mix" had evolved to include many different ideologies.
That made monitoring them far more complex.
"It has become more complicated in law enforcement around the world," he said.
"We are connected to a wide range of law enforcement agencies around the world ... some aspects of our monitoring of individuals are world-leading.
"That threat continues to evolve (but) what is of most concern to us is not so much about defining a particular ideology."
Intelligence agency ASIO raised the terror threat from "possible" to "probable" in 2024 after eight attacks or disruptions involving alleged terrorism in a four-month period.
One of those viewed as terror-related was the Wakeley church stabbing in April, where two Christian clerics were injured in an attack during a service in western Sydney.
"In some ways we've come a long way (in the past decade), and in other ways we haven't gone far enough when you look at the incident at Wakeley," Mr Hudson said.
The deputy commissioner downplayed the threat posed by neo-Nazi organisation the National Socialist Network after it reportedly orchestrated a series of anti-immigration rallies across Australia in August.
As the Melbourne rally concluded, NSN leader Thomas Sewell allegedly led a group of about 30 men to storm Camp Sovereignty, an Indigenous protest site in the city centre.
While monitoring the group, Mr Hudson said it would not be designated as a terrorist organisation.
"We've always monitored neo-Nazis, or radical right-wing groups in NSW through our known entity management model ... there are neo-Nazis on that list and we will continue to police that," he said.
"We are constantly vigilant for the threats (but) I can say that actions are what concern me more than words."
Mr Cheng's son Alpha delivered a moving tribute to his late father at Thursday's memorial, urging those in attendance to remember him for his positive qualities rather than by his murder.
"It's been 10 years of thinking and wondering 'I wish dad was still with us today'," he said.
"It was here in this very square 10 years ago that dad was shot in a violent act of terror and never made it home.
"I should want to fight fire with fire - but Confucius said: 'He who seeks vengeance should dig two graves'."
Cheng died aged 59.
