A teenage bikie associate gunned down and killed in Sydney's southwest had been shot two weeks earlier but refused to co-operate with detectives.
Comanchero affiliate Bassil Hijazi was also spoken to by police about a drug charge hours before he was fatally shot in a Bexley car park on Monday night, 15 minutes after another man was killed in an unrelated shooting a few kilometres away.
Hijazi, 18, survived a bullet to the neck on July 16, reportedly in retribution for the slaying of two rival bikies earlier in the month.
"The fact is, that 18-year-old male was very well known to police," NSW Police Commissioner Andrew Scipione told reporters on Tuesday.
"Our most recent interaction with him was at 7pm last night when he attended the St George Police Station hours before he was killed."
It is understood he was reporting at the station as a bail condition related to a drug supply charge.
Mr Scipione's comments came as Hijazi's mother, Hannah, issued an emotional challenge for his killer or killers to own up.
"If you're a man you would have confronted him like a man," ," Mrs Hijazi told the Nine Network.
"If you're still a man, please come and tell me why.
"The person that was with him (last time he was shot) never came forward.
"I know who that person is and he was with him this time as well but he refuses to tell the police everything."
Mrs Hijazi said police needed to do more.
"Get those guns off the street, do your job right," she told them.
"You're not doing your job right. My son's gone."
Homicide Squad Commander Detective Superintendent Mick Willing said Hijazi had refused to co-operate with officers trying to investigate the attack on him two weeks ago.
"He was not forthcoming with information," Supt Willing said.
"It's very hard to help someone when they're not helping themselves."
Social media websites were flooded with tributes to Hijazi on Tuesday.
Rebecca Babyye wrote on Facebook: "Sill (sic) can't get through my head that he's gone. Keeps going through my head that phone call we had a few days ago ):rip Bassil Hijazi."
The shooting came about 15 minutes after a 35-year-old man was shot near his home in an apparently unconnected incident four kilometres away in Earlwood.
Vasko Boskovski, who died in hospital early on Tuesday morning, was also known to police.
The father-of-two was a director of Elite Group Solutions, a debt collection and security firm based in Burwood.
Police denied reports the killings are part of a major bikie war.
"The reality is a lot of these young men are living the lives of wannabe gangsters," Mr Scipione said.
Officials have urged family members with any information to come forward.
"If you want to stop your loved ones, your friends, your family - if they're in organised crime (or) outlaw motorcycle gangs - falling at the end of a gun, then make the call to police," Police Minister Michael Gallacher said.
"It will be the greatest gift you potentially could give your loved ones, and that is the gift of life."
He said opposition claims the government refused a police request to establish an organised crime squad to crack down on bikies and gangs was a "complete misrepresentation".
The request related to an anti-money laundering task force.
