The family of a carpenter who was killed by a sword-wielding attacker have said they had “no idea” his brother was the man seen in CCTV  footage taken at the scene and released by police.

David Dick, 36, was attacked as he walked out of a lift in the carpark of the Westfield Doncaster shopping centre just after 6am last Friday.

A day after his mother made an emotional appeal to identify the suspect, detectives have appealed for the victim’s brother, Jonathan Dick, to turn himself in for questioning.

Police yesterday released CCTV of a suspect seen at the scene the day before the attack, who they believed may have been plotting a strategy.

Mr Dick’s family watched the footage but said they did not realise that the man in the video was David’s 39-year-old brother.

David’s devastated family views the CCTV footage. (9NEWS)

“(They had) absolutely no idea,” Homicide Squad Detective Inspector Mick Hughes said.

“We had shown the footage to the family,” he said.

“I’ve had the question, how would you not know that is your son?

Police released this photo of 39-year-old Jonathan Dick. (Supplied)

Mr Dick’s mother, Carol Cloke, broke down in tears while remembering her “magical” son. (9NEWS)

“But he has recently changed his hairstyle and cut it quite short.

“His family are under so much stress that I can’t second guess why they wouldn’t recognise him.

“Not one of them had an inkling that this could have even been a possibility.”

Det. Insp. Hughes said the family was devastated by the revelation that Jonathan is being treated as a person of interest.

“They were so traumatised yesterday, and of course that has been compounded as we look at him (Jonathan) as a person of interest,” he said.

Detectives believe Jonathan may be headed to New South Wales or Queensland.

He may be driving one of two vehicles – a 1997 blue Ford Fairmont sedan with registration ONV954 or a white 2002 Ford Falcon station wagon with registration RIL435.



Police said the suspect was in the shopping centre carpark the day before Mr Dick was attacked. (Supplied)

These are the two vehicles police believe Jonathan may be using. (Supplied)

Mr Hughes said yesterday that David was targeted by his assailant but did not suspect the attack.

“He (the suspect) hits him pretty hard the second he stepped out of the elevator,” Det. Insp. Hughes said.

“This is not a random attack. This is a vicious, calculated attack.”

Detectives said the murder weapon, which is believed to be a sword, had not been located.

They believe the suspect fled the scene through a fire exit and then headed south towards Doncaster Road.

David’s distraught mother, Carol Cloke, yesterday remembered her son as a “fun loving, magical person”.

“David was the most beautiful, fun-loving, magical person and we all loved him so much,”  she said.

“He was very happy. He has been really settled down for the last while now and getting on with his life.

“This just came out of the blue.

“All I know is that I will never see him again.”

David was a carpenter and was walking to work when he was attacked.

He was found severely injured an exercise group that was about to hold their regular boot camp session nearby.

Three members of the group performed CPR on David but were unable to save him.

Anyone with information is urged to contact Crime Stoppers on 1800 333 000.