Summary inquests into the homicides of Raim Dalipi, who was shot in 2005; Robert Hoff, who was beaten to death in 2011; and Sameh Matar, who died of a gunshot wound to the pelvis in 2010, were held at the Victorian Coroners Court on Thursday.
Leading Senior Constable Kelly Ramsay told Judge Sara Hinchey the murderers had never been identified or charged.
Mr Dalipi, 58, was involved in the sale of cannabis at the time of his death.
The Macedonian immigrant had been in a tumultuous relationship with his wife when a man knocked on their front door in Geelong in September 2005 after Mr Dalipi had purchased a bale of illegal tobacco.
The man asked to buy half a kilogram of the tobacco and left to get money.
He returned a minute later, pushing Mr Dalipi and entering the couple's home with another man who was holding a handgun.
The second man placed a blanket over Mrs Dalipi's head and threatened to kill her if she removed it.
Mrs Dalipi, who used her phone to get help, heard a gunshot.
Upon hearing the two men leave, she removed the blanket from her head and saw her husband injured and unsteady on his feet.
Mr Dalipi died later that night from a gunshot wound to his abdomen.
Robert Hoff was a 50-year-old man who lived at Carrum Downs. He was attacked by a seemingly random assailant while on his way to catch a bus to his job as a forklift driver in March 2011.
Sen Const Ramsay said Mr Hoff was known as a gentle, sensitive man who had never been in a relationship.
A resident found him on the ground with blood around his head, dead from blunt force trauma.
Sameh Matar was a 23-year-old Lebanese immigrant who was on bail for drug trafficking and possession at the time of his death.
He died of extensive blood loss from a gunshot wound to the pelvis after an argument with a group of men at Hadfield in July 2010.
Summary inquests are mandatory in homicide cases where no one has been charged.
No witnesses are called during the proceedings.
Coronial inquiries can be reopened if new information into the homicides is discovered.