Three teenagers have been arrested over the murder of Paul Costa in a Brunswick West reserve on July 3.
A 17-year-old boy and an 18-year-old man were arrested by the Homicide Squad, while a 16-year-old was arrested in Newcastle, NSW.
All three of these males have been charged with one count of murder.
The 16-year-old will be extradited to Victoria on Friday.
It is understood that Mr Costa was killed in a botched carjacking, with his car found dour days later.
Mr Costa was a father of four.