A Gumtree deal turned fatal in suburban Melbourne when a would-be buyer of audio equipment allegedly returned with a hit squad and a man was shot in the head.
Four men faced court on Monday, but others are still on the run, over the weekend killing of Duane Hutchings, 44.
The father-of-five died in hospital after allegedly being confronted by a group of men inside an Oakleigh East home and shot with a sawn-off shotgun.
Tony Panagiotou, 56, is charged with murder.
He faced Melbourne Magistrates Court along with sons John, 18, George, 22, and 24-year-old Jonathan Atalalis, who are each charged with trespassing with intent to assault while carrying metal batons.
The trio is also accused of intentionally and recklessly causing injury to Mr Hutchings, and assaulting him with a baton.
The court was told John Panagiotou operates a sound equipment hire company called Love It Loud - Dj Equipment & Party Hire.
Equipment was dropped to a woman's home on Saturday, who then allegedly advertised it for sale on Gumtree.
A man who went by the name "Steven" contacted the woman and went to her home about 5.30am, saying he was happy with the equipment and would retrieve cash from his car.
However, "Steven" allegedly returned with a group of about six other men, who assaulted Mr Hutchings with a metal pole before Tony Panagiotou allegedly shot him in the back of the head.
Mr Hutchings died later that day in The Alfred Hospital.
Three of the men then visited Doncaster Police Station, saying they had equipment stolen valued at up to $30,000.
John Panagiotou was refused bail on the basis the shotgun and two or three alleged co-offenders were still at large as his "very distressed" mother sobbed loudly in court, comforted by her daughter.
"I don't know who's got that gun," a concerned magistrate said of the missing firearm.
George Panagiotou will return to court on March 7 to apply for bail.
Atalalis did not apply for bail and his matter was adjourned along with those of Tony and John Panagiotou to June 3 for committal mention.