Two men have been charged after a man was executed at his home in a possible case of mistaken identity.
Police arrested a 43-year-old and a 19-year-old on Wednesday morning, almost six months after plumber John Versace was shot dead in the driveway of his Condell Park home in Sydney's southwest.
Both men are accused of driving the vehicles involved in the 23-year-old's death and have been charged with murder.
"They're obviously known to each other in some way," Detective Superintendent Jason Box told reporters on Wednesday.
"There was a lot of planning involved."
Mr Versace was backing his car into his driveway about 10.30pm on May 19 before another vehicle pulled up and parked him in.
A man holding what is believed to be a Glock pistol exited the vehicle from the rear driver's side door and fired up to 10 bullet at the plumber, who was treated by paramedics but could not be revived.
While neither man arrested on Wednesday is believed to have pulled the trigger, the older suspect allegedly planned the murder and drove the gunman to the victim's home.
They allegedly fled the scene to a number of staged vehicles which were later set alight.
The younger man met with them soon after and drove them to another location, police say. He also allegedly helped plan and prepare for the murder by acquiring and staging the cars.
Since the shooting, police have been investigating whether Mr Versace was shot in a case of mistaken identity.
Asked if they had discerned the motive behind the 23-year-old's death, Det Supt Box said a number of theories and evidence were being explored.
"Nothing suggests that Mr Versace was anything but a hard working young man who was living at home with his family and trying to set himself up for the rest of his life," he said.
The two men have been refused bail and appeared in court on Wednesday.
Mr Versace's murder occurred during a spike in public shootings across the city.
Less than a week after his death, two men were hospitalised after a gunman sprayed a ute with bullets in Granville and in October, former UFC fighter Suman Mokhtarian was gunned down while out for a walk.
