Illawarra detectives keep open their files on unsolved murders in the hope that one day they can bring closure for the victims' families.
Officers take DNA samples from relatives just in case new clues come to light that can one day link killers to their victims.
Detective Senior Sergeant Darren Kelly, investigations manager with Wollongong Local Area Command, said certain cases had "stuck with him" over the years and police too felt the anguish of not being able to solve a case.
"From our perspective, a case is always open and we are always seeking information," he said. "We always have regret when a family doesn't have that closure."
As National Missing Persons week approaches, Snr Sgt Kelly has urged people to come forward with any information that could help solve some of the Illawarra's biggest mysteries.
After work on the night of June 7, 2001, Rachelle Childs supposedly went to see someone at the Bargo Hotel.
About seven hours later, her badly burnt body was discovered in bush near Seven Mile Beach, not far from Gerroa and about 90 kilometres from her Bargo home.
In 2008, Coroner Jane Culver ruled the 23-year-old had been deliberately killed but police did not have enough evidence to identify a culprit.
Three years later, the state government doubled a reward to $200,000 for information leading to a conviction for her murder.
Her father, Graham, said at the time that Rachelle would never have gone anywhere with a person she did not know.
She was last seen alive driving towards Bargo about 5.15pm after she left work at the Camden Holden car dealership, where she worked as a saleswoman.
During a 2006 inquest, Ms Childs's former boss at Camden Holden, Kevin Correll, was a prime suspect, named as one of nine persons of interest.
When he appeared at the inquest, he declined to answer several questions on the grounds the answers might incriminate him. He denied killing Ms Childs.
A former professional boxer, standover man and murder accused, Charles Chicka Reeves himself became the victim of foul play in 1979.
He was gunned down as he drove along the Port Kembla coal loader road on January 23.
The theory was that Mr Reeves was murdered because he had tried to "muscle in" on Wollongong's gambling and prostitution scene. Detectives met with a wall of silence.
Kay Docherty and Toni Cavanagh
The two teenagers who went missing from Warilla 35 years ago were most probably murdered within days of their disappearance, a coroner ruled.
Kay Docherty, 15, and Toni Cavanagh, 16, were last seen alive at a bus stop outside the Warilla Grove Shopping Centre about 7.30pm on Friday, July 27, 1979. The pair reportedly planned to hitchhike to Wollongong to attend a disco.
Kay's twin brother, Kevin, had been due to meet his sister at Toni's house at 9.30pm to walk her home. However, neither returned to the Cavanaghs' Martin Street house in Warilla.
They have not been seen since.
Deputy State Coroner Geraldine Beattie said the initial investigation into the girls' disappearance was "scant at best", with police at the time dismissing the pair as "runaways".
However, since the case was reopened in 2004, police had chased down hundreds of leads and conducted an extensive, Australia-wide search for any trace of the girls.
Kiama nurse Jackie-Lee Walsh was last seen by her boyfriend when she drove him to work at 8am on Friday, April 14, 1989.
She never made it to an appointment with her accountant that morning, or lunch with a girlfriend.
A pool of blood found in her red Torana, parked outside Warrawong's Open Hearth Hotel six days later, convinced police Ms Walsh suffered a savage death. They believed she was either viciously beaten or had her throat cut, then was bundled into the boot where she bled to death before being dumped.
Police later discovered Ms Walsh had gone to a house in Moss Vale to buy drugs on the Friday and left at 3pm to meet another friend in Kiama.
But she was never seen again.
The prime suspect in the murder of a man whose decomposing body was found in a makeshift coffin in bushland at Mount Ousley in August 2009 is most likely dead.
The inquest for Chinese national Jun Chen found he had been stabbed to death in a North Sydney karaoke bar on March 2 that year.
The man who police believed was responsible for his death, Sydney-based solicitor Gary Gold, fled to Hong Kong on March 9, five days after friends told authorities that Mr Chen was missing. Mr Gold subsequently changed his name to James Wu and a man by that name was found dead just under two months later.
Despite Mr Chen's family's belief that Mr Gold faked his own death to evade police, Deputy State Coroner Geraldine Beattie accepted that "on the balance of probability" the 37-year-old lawyer was dead.