Tarek Ayoub was killed in a hail of bullets in a targeted attack outside a unit block at Parramatta in the city's west, early on Monday.
Multiple shooters are on the run after the murder, Sydney's first gangland killing in six months.
The 29-year-old Yagoona man was a well-known figure in organised crime circles and was referred to as "the Angel of Death", according to police.
NSW Police Commissioner Karen Webb admitted investigators held fears the killing could trigger an escalation in gangland tensions that appeared to have simmered down in recent months.
"It's always a concern where there is an act of violence, that there may be retribution," she told reporters.
"Certainly we will have officers working around the clock to not only investigate the homicide, but also whether any retribution could be envisaged, and that's always at the front of our mind."
Sydney was hit with more than a dozen tit-for-tat gangland killings beginning in 2020 as rival crime organisations fought for control of the city's lucrative drug trade.
The public attacks included five targeted shootings during a week in mid-July.
But there has been a lull in the carnage in recent months after a series of arrests, which investigators say have helped dismantle one of the major gangs behind the violence.
Homicide Squad commander Danny Doherty said Ayoub "certainly lived by the sword and died by the sword".
"This is no surprise to the police that he was murdered in (this) way," he said.
Such was his reputation and links to multiple crime networks, police were having a hard time drawing up a shortlist of potential killers.
Detective Superintendent Doherty said there were "too many suspects, too many motives" for killing Ayoub, who had been charged with a string of firearm and drug offences and had been linked to at least one murder investigation.
"So far we've established that he was visiting an associate at Parramatta, where he was shot down in the hail of bullets (in an) execution-style murder in this car park," he said.
"They weren't taking any risk of missing him and they certainly didn't miss him."
A stolen Audi was found burning in nearby Granville after the murder. (Supplied by Fire and Rescue Nsw/AAP PHOTOS)
The meeting with the associate appeared to be an "innocent" catch-up but detectives would probe who knew Ayoub's expected movements.
A second crime scene was set up in nearby Granville, where a stolen Audi SUV was found alight about 3.45am.
Two men were reportedly seen leaving the scene in another vehicle, police said.
The "well organised, well planned" shooting had the hallmarks of an organised-crime execution involving numerous people, Det Supt Doherty said.
"Normally ... there are people that execute the plan and commit the murder, there are also people that obtain their (getaway) vehicles, get rid of the vehicles and the ones that pull the strings and arrange the murder," he said.
The fire took 45 minutes to put out and threatened nearby cars and properties, Fire and Rescue NSW said.
