A man who was slain in a calculated, machete attack at a Melbourne shopping centre was stalked by his attacker for days.
David Dick, 36, was struck viciously without warning as he stepped out of a car park lift at Westfield Doncaster shopping centre at 6am last Friday.
Detectives on Tuesday say they are still not sure why the carpenter from Doncaster was killed.
But they are sure they know who might be able to help them, releasing images and CCTV footage of a man in his 30s they want to talk to.
Officers say Mr Dick never got a chance to defend himself in the brutal attack.
He was hit hard in the head with a long-edged blade.
Detective Inspector Michael Hughes said Mr Dick regularly walked through the shopping centre on his way to catch a bus to work.
"This attack was vicious. He was waiting for David to get out of the lift and struck him without warning," Det Insp Hughes said.
"There will be connection between David and this man, he was following him and this is a calculated attack."
The man they want to talk to followed Mr Dick through the shopping centre on the day before the murder.
He was pictured carrying a case believed to contain the long blade weapon.
Mr Dick's mother Carol struggled to speak through her tears on Tuesday, but told reporters her son was a "beautiful, fun loving, magical person".
"He wasn't all pure, but who is," she said.
"I'm not sure why this has happened."
His uncle John had dinner with him on the Tuesday before he died, and says his nephew was happy and didn't seem stressed.
"We just talked about his job and life in general, he was extremely happy and he'd just started to establish a relationship with a girl."
"We want to thank the people that came to his aid, they were very brave."
Mr Dick was found by a fitness group about 6.10am in the car park lift lobby.
They tried to help and called paramedics.
Police believe the attacker might have been injured and sought medical attention.