“We’re a long way from establishing a full picture of this man, and his exact motivations still remain a mystery to us”, New South Wales police commissioner Andrew Scipione said.
It has emerged that his sister Shadi may have been attempting to reach Iraq or Syria the day before the shooting as she flew out of Australia on a flight bound for Istanbul on Thursday.
Neighbour Maggie Semaan said the student and his family were good neighbours.
Outside the station, he waved his gun at police and screamed “Allahu akbar” at them before he was killed in the ensuing gunfight.
“It appears an officer has discharged his weapon, responding to a report that a person had been shot”, the statement read.
The police association says the force has been slow to act after radicalised teen Farhad Jabar Khali Mohammad shot and killed worker Curtis Cheng at close-range.
Australia has stepped up its efforts in countering the risk of extremist attacks, lifting its terror threat alert to high a year ago, and Scipione said police were aware they could be targeted.
The teenager was born in Iran and had been attending Parramatta’s Arthur Phillip High School.
Australian police spoke to the year-10-student about the alleged posts on social media, in which he reportedly hoped the police would “burn in hell”.
Sources said the building had been “cased” and there had been “chatter” in recent weeks about a potential attack, but the target was not clear.
Malcolm Turnbull said in a separate news conference Saturday that governments and police are working together to ensure the security of the country after Friday’s “cold-blooded murder”. “They’re quiet. We’ve never known that there was any trouble”, she said.
“We need to be mindful of that but we also need to accept that the vast majority of them are very much supportive of the broader Australian community”.
Several of the arrests have involved young people who were said to be plotting terrorist attacks. Officials had not received any warnings that a shooting was imminent, he said.
“I’ve viewed a number of items of footage and I can tell you, this was a brutal crime, a bad crime”, Scipione said. “The Muslim communities are our absolutely necessary partners in combating this type of violent extremism”.