Rodney Elkass, 37, was killed in his Toyota Hilux in Pennant Street, Castle Hill, at 12.45pm on September 29 last year from a gun shot to the head.

The inquest into the death of the Granville painter and handyman heard on Monday that the officers, responding to a triple-zero call by two men involved in an earlier confrontation with Elkass, ran towards his ute with guns drawn as he was stopped in traffic.

In his opening address, counsel assisting the coroner, Peter Hamill, SC, said witnesses saw three men in dark suits running towards Mr Elkass with their guns drawn and yelling at him to stop and "get the f--- out of the car".

At least two witnesses saw Mr Elkass brandish a black pistol in the direction of the officers, two of whom then fired four shots at him. One of the shots struck the 37-year-old in the head, killing him almost instantly.

But none of the civilian witnesses to the shooting said they heard the detectives identify themselves as police as they ran towards Mr Elkass.

"One of the key issues that is likely to arise in this inquest is whether or not the officers identified themselves verbally as police officers," Mr Hamill said.

"Detective Senior Constable Paul Gardiner and Senior Constable Michael Wilkins said that they did [identify themselves as police officers] but evidence of that has been contradictory and controversial."

Earlier, the inquest heard that Mr Elkass had driven to Pennant Street, which runs beside a public library, the Castle Towers shopping centre and Castle Hill police station, after an altercation with two men in which he had also pulled his gun.

Mr Hamill said one of the two men, referred to as "Witness A", was a former workmate of Mr Elkass who had racially abused him and then been involved in a fist fight with him 10 years before.

Witness A had seen Mr Elkass in his ute with his teenage nephew, walked over to the pair and said, "Want to go round two?"

Mr Elkass drove away but was pursued by the two men through the streets of Castle Hill.

"Rodney then stopped the car and the two men approached him, which led to a verbal altercation," Mr Hamill said.

Mr Elkass then produced his Glock pistol and racked - the action that sends a bullet into a gun's chamber - sending the men running back to their vehicles to call triple-zero.

This altercation and the subsequent call to police had set up the circumstances for what was to come.

"Rodney didn't instigate this [first] confrontation, but his actions, both in having the gun and producing it, led us to a series of events which led us to this inquest," Mr Hamill said.

He said that after dropping off his nephew, Mr Elkass had driven off in the direction of Witness A's house to confront him, but then did an unexpected U-turn, possibly because he feared for his nephew's safety.

This took him back past the Castle Hill police station where the three plain-clothes detectives were running out in response to Witness A's triple-zero call.

They confronted Mr Elkass as he was stopped in traffic, shooting him in the front seat of the Hilux.

The inquest heard that the 37-year-old had a licence to possess the Glock pistol but that this prohibited him from carrying it in public.

The inquest, before Coroner Hugh Dillon, continues.