Police believe at least three members of a drug syndicate may be linked to the murder of a Melbourne father shot dead in front of his young family in 2015.
Toan Truong, 43, was asleep in his home on Allison Street, Sunshine West, with his pregnant wife and three-year-old child when he was woken by an armed intruder around 5am on February 3 last year.
Mr Truong chased the man into a rear bedroom where the intruder fired his gun, fatally wounding the father in front of his wife and child.
The killer then fled the scene.
Detective Acting Inspector Peter Trichias today said police believed the killer was operating with two others.
The offenders are believed to be associates of a thieving syndicate targeting houses with hydroponic cannabis crops in the western suburbs during 2015 and 2016.
Five men have been charged over aggravated burglaries in Caroline Springs and Deer Park where they have allegedly stolen or tried to steal crops.
A 22-year-old Hillside man has been charged over an aggravated burglary in Deer Park in July 2016.
A 31-year-old man has been charged over an aggravated burglary in Caroline Springs in August 2015, and a further three men have been charged over a separate aggravated burglary, also in Caroline Springs in August 2015.
Authorities have released a facial composite image of one of the offenders allegedly seen at the property.
CCTV footage has also been obtained by police showing a dark-coloured sedan speeding away from the area shortly after the shooting.
Investigations have identified two vehicles of interest - a dark coloured BMW two-door coupe and a Ford Falcon sedan, seen in the area about 45 minutes before the murder.
Det Acting Insp Trichias said was nothing to suggest Mr Truong knew his killer or had any links to the syndicate.
"Toan was a decent person. He was a family man. He worked hard," he told reporters.
"He's done the wrong thing, we know that, but he's not an entrenched criminal."
Anyone with information is urged to contact Crime Stoppers on 1800 333 000.
With AAP.