Sandra Cawthorne was heavily pregnant with her third child when she was shot dead in Sydney's west 10 years ago.
But her killer or killers have never been caught.
Her mother Patricia Roberts has now made an emotional plea for help to solve the horrific murder.
"It's been 10 long years since Sandy was killed," Mrs Roberts said.
"Her two sons, now aged 11 and 14, still wonder who killed their mum."
Ms Cawthorne's body was discovered in the middle of Murtha Street, Arndell Park on April 12, 2004.
The mum of two, 29, had been shot numerous times in the head and body.
But despite a number of strong leads, police have never been able to close the case.
"The police have done an excellent job but they really need the assistance of the public to help them find my daughter's killer," Ms Roberts said.
"I am pleading with anyone out there who has information that could assist police to please contact Crime Stoppers."
Detective Inspector Con Galea said he's certain someone in the community knows who killed Ms Cawthorne.
"Sandra's poor mother and her two boys still don't know who killed her or why. They've suffered for far too long, and deserve closure," he added.
Police released pictures of a truck on Tuesday as part of the appeal for help.
The truck was seen in the Arndell Park area around the time of Ms Cawthorne's death.
Police believe the truck may have been used by Ms Cawthorne's killer or killers as a getaway vehicle and hope the images may jog someone's memory.
