The family of Sydney father Walid Kamoun cannot understand why he was shot in the head through the window of his townhouse on Monday night.
Police said the 54-year-old market stall owner was shot inside his Yagoona home in what was a "specific and targeted" attack just after 9pm.
He remained in a critical condition in hospital on Tuesday as police searched for a gunman described as wearing dark clothing and a hooded jumper.
The victim's nephew, Omar Abouchanab, 17, said his uncle had five children and had no known enemies.
"He's the most humble person you'd ever meet - he wouldn't hurt a fly.
"We are shocked about it."
Omar said his mother had spent most of the night with his uncle in hospital and his family planned to go back to sit with him later on Tuesday.
Bankstown police said they were not sure why anyone would want to harm Mr Kamoun.
One neighbour told reporters the gunman had knocked on doors asking where Mr Kamoun lived before the shooting.
"Information that we have at hand would indicate this was a specific and targeted attack, certainly was not a random incident," Superintendent David Eardley he said.
"A gunshot was fired through the window of the building striking the male person," he said.
Omar said he saw his uncle last week when he came over to get supplies for the market stall he owns.
"He comes every day to my house to get supplies," he said.
Police were seen using fingerprint dust on the fence of Mr Kamoun's townhouse and took a number of items away in brown evidence bags.
Police said at least one witness had seen a man they believed had been involved in the shooting.
"He was seen in the near vicinity," he said.
Superintendent Eardley said Mr Kamoun was known to police for minor matters and did not believe he had links to any organised crime gangs.
Police are asking anyone with information to call Crime Stoppers on 1800 333 000.
