A Sydney detective has described the moment when he accidentally shot and killed his mate during an ill-fated drug bust in south-west Sydney.
"No thinking ... the body just reacts," Senior Constable David Roberts said of firing the shot that killed Constable Bill Crews.
"Unfortunately when you've got a split second, you don't have the luxury of considering a lot of things.''
The shooting occurred on the night of September 8, 2010 when Senior Constable Roberts and fellow members of the Middle Eastern Organised Crime Squad were raiding the Bankstown garage of Phillip Nguyen following a tip-off that Nguyen was selling drugs to Sydney's notorious Kalache and Hamze crime families.
As they walked through the underground garage, Nguyen came out from behind a car with a silver pistol and fired several shots.
In the ensuing gunfight, Roberts fired a single shot that hit and killed Constable Crews, an officer in just his third week with the crime squad.
He told the court he was not in position for a well-aimed shot – retreating backwards away from Nguyen and simultaneously trying to take cover.
The bullet struck Constable Crews in the head.
"Cruisy was lying down on the ground...lying on his front," Senior Constable Roberts said during a recorded police interview played to the court.
"I was yelling, 'throw the gun down we need to get to our mate!'
When asked whether he acknowledged that firing his gun in such circumstances was risky, Senior Constable Roberts said he was simply responding to the threat.
''Phillip Nguyen was firing his gun at us. I was looking at him, my concentration was on him,'' he said.
The inquest heard that Senior Constable Roberts was back on duty a month after the incident.
He had received counselling but no additional training.
Unlike another officer involved in planning the raid, Senior Constable Roberts did not resile from the decision to categorise the operation as ''low risk'', and said he had not changed the way he executed search warrants.
"If there's a risk attached to a search warrant I will always ensure that those attending are properly protected. If there's no information to suggest that firearms are present or that the offender is violent, then it would be an overreaction and I'll assess the search warrant in the same way I approached this matter.''
Senior Constable Roberts said he did not support the idea of police always being required to wear ballistics jackets whenever they executed search warrants.
"It's just not practical," he said.
"It's not appropriate to show up to the home of an innocent 75-year-old couple whose son's in jail for armed robbery or something with six big blokes wearing ballistic gear."
The inquest continues.
