In all his years with the NSW police, Commissioner Andrew Scipione has never seen a greater act of bravery than the three officers who stopped a lone gunman outside the force's headquarters in Sydney's west.
A 15-year-old boy shot dead Curtis Cheng, from the NSW police finance department, as he was leaving the State Crime Command in Parramatta on Friday afternoon.
He then continued to spray bullets, but three officers leapt to action and the killer was shot dead as they returned fire.
"Over my time in this organisation... for many many years, I've seen some acts of bravery. I don't think I've seen a greater act of bravery than what I saw last night," Mr Scipione told media on Saturday.
"These three special constables certainly put their lives on the line, knowing they were under fire, probably aware that somebody had been shot, could even have been aware that it was one of their own, still went forward, engaged and removed the threat.
"Even after the threat had been stopped the officer that was involved went up and rendered assistance.
"Incredible. I was certainly touched."
Mr Scipione said there were people walking down the street at the time the shoot-out happened, and it was difficult to guess just how many lives had been saved.
It has been revealed the teenage gunman was of Iraqi-Kurdish background, born in Iran, and his actions were linked to terrorism.