Police have no idea why a man, who was shot dead inside a police station in Sydney's west, walked into the premises and allegedly started threatening officers.
The man, believed to be aged in his 40s, is yet to be identified, but police say yesterday's incident at Quakers Hill police station is not believed to be terrorism-related.
A sergeant with 24 years' experience fired the fatal shot after an altercation that lasted just seconds at 10.40am local time, Assistant Commissioner Denis Clifford said outside the station.
A number of officers were in the police station and a 12-year old boy was also in the foyer when the man entered the building.
"There was a shot fired by the sergeant. It struck the man. He was rendered assistance but passed away a short time later," Clifford said.