Macchour Chaouk was gunned down on Friday in the backyard of his fortified home in Melbourne's west by a drive-by shooter.
Police arrested a 57-year-old man over Chaouk's death.
On Friday afternoon, busy Lygon Street in Carlton was thrown into chaos by the shooting deaths of two men at a pokies venue in an apparently unconnected slaying.
With police resources stretched to the limit and investigators chasing up leads in both cases, the Chaouk family was planning its response.
"The weak, dirty dogs killed him on Ramadan," says a Chaouk family statement obtained by The Age newspaper.
"His blood does not come cheap, especially in Ramadan."
A family spokesman told the newspaper: "Every dog has its day."
Chaouk, 65, was the head of a clan with a long history of crime which is involved in a violent feud with the rival Haddara family.
A magistrate last month referred to the "ongoing war" between the two families, while police said the feud with the Haddaras was an obvious line of investigation.
Homicide detectives will resume questioning a 57-year-old man from Altona North arrested over the Chaouk shooting on Saturday.
The man has not yet faced an out-of-sessions court.
A suspect has been arrested over the Lygon Street slayings and will be questioned again on Saturday.
Two men were shot dead and a third is believed to have fled from a gunman who shot up Players on Lygon in Carlton around 4.45pm on Friday.
