West Australian police have revealed they are hunting for a dark-coloured station wagon they believe may have ploughed into murder victim David Liam Johnson before he was shot through the head.
More than a week after the body of Mr Johnson was found in a Perth park with a bullet wound to the head, detectives are still searching for a motive and a killer.
Following a public appeal for information from Mr Johnson's family late last week, police said over the weekend a post-mortem had revealed he had been hit by a car somewhere else before being killed at Lime Kiln Field, Swanbourne.
West Australian police said forensic evidence had shown the impact with the car occurred at another location, before Mr Johnson was taken to the park where he was shot and killed.
Detectives are now interested in identifying a dark-coloured station wagon which they believe might have been involved.
A vehicle similar in appearance was seen driving in the Swanbourne area between 11pm and 11.30pm on the evening of March 8.
"Detectives would like to hear from anyone who might be able to assist in identifying the vehicle," a statement from WA police said.
Mr Johnson's sister Ele and aunty Jennifer, who did not what their surnames published, have described Mr Johnson's as "a free spirit" with no known enemies, who was known in the Mandurah and Fremantle areas.
"He would never hurt anybody, he was very kind hearted and with that gorgeous big smile he had you could not help but like him. He was friendly and chatty," Jennifer said.
Anyone with information is urged to contact Crime Stoppers on 1800 333 000, and callers may remain anonymous.