These crimes not only shook Australians but they even shook the police as most remain unsolved.
Read some of the most disturbing murders that remain a mystery below:
Walsh Street Murders
Former Victorian Police Detective Inspector John Noonan admits not a day goes by without him recalling the horror of October 12, 1988.
As he arrived in the early hours of the morning at Walsh Street in the Melbourne suburb of South Yarra, John found the dead bodies of two young police constables, Damian Eyre, 20, and Steven Tynan, 22, who had been ambushed in a hail of bullets by a criminal gang.
The two constables had been called out to investigate an abandoned stolen car, but it was a trap – the car was a revenge tactic set up for the shooting death by police the day before of Graeme Jensen.
“I will never forget the sight of the stolen car and the police van with its doors open,” John tells Woman’s Day.
“It was a gruesome and violent scene of two young men murdered in a callous manner.
“But it was especially confronting as it was fellow police officers and that resonated with all of us in the force.”
John, now 70, spent the next three years heading up the investigation, piecing together evidence that culminated in noted criminals Victor Peirce, Trevor Pettingill, Anthony Farrell and Peter McEvoy standing trial in March 1991 for the murders.
The case fell apart, however, when a key witness refused to testify and the four were acquitted.
“We were very disappointed with the result,” says John.
“Every time I think of Damian and Steve, I do feel like we let them down a bit, that we didn’t get a result at the trial. But it also meant we could not give up.”
Ever since, John has been advocating for a coronial inquest.
“Because of all the evidence that wasn’t heard in court, that had been ruled out for whatever reasons, there was still plenty that could go before the inquest, and that might result in a different finding,” he explains.
Despite the many requests, including those by the Eyre and Tynan families, an inquest continues to be rejected.
Even though original suspects Victor Peirce and Anthony Farrell have since died, John believes there is enough compelling evidence to make an inquest worthwhile.
Sadly, he doubts it will eventuate. “It will take something extraordinary to do so,” says John, “And while I do live in hope, it’s not looking positive.”
Fairy Meadow beach mystery
Three-year-old Cheryl Grimmer vanished from a beach on the outskirts of Wollongong, NSW, on January 12, 1970, having spent the day there with her three older brothers and mother.
She was last seen near the showers, and witnesses later told of seeing a man carrying a child wrapped in a towel towards the beach carpark.
In 2019, the murder trial against a man who was a teenager at the time of Cheryl’s disappearance collapsed.
The judge ruled the “confession” given to police in 1971 could not be presented as trial evidence as, among other reasons, no adult had been present during the interview.
Earlier this year, another witness came forward, saying they saw a teenage boy carrying a small child but the NSW Attorney-General has rejected an appeal for a fresh inquest.
“Cheryl was three years old. She was defenceless and no one seems to care about her,” Cheryl’s older brother Ricki Nash said of the decision.
Woman in the boot
Melbourne mum Maria Korp was found in the boot of her red Mazda near the city’s Shrine of Remembrance on February 13, 2005.
She had been reported missing by her family after disappearing four days earlier. Incredibly, she was found still alive but suffering from severe oxygen deprivation, head injuries and extreme dehydration.
Maria, 50, was rushed to a nearby hospital and put on life support but tragically died six months later.
Her husband Joe Korp took his own life on the day of Maria’s funeral after being charged with her attempted murder.
It’s alleged he convinced his mistress Tania Herman to kill Maria so they could be together.
Herman was found to have choked Maria with a strap, then put her into the car boot, thinking she was dead.
Herman was found guilty of attempted murder and served eight years in jail.
She was released on parole in 2014 and claims she was coerced into the killing by Korp.
Maria’s now-adult daughter, Laura De Gois, told A Current Affair in 2010 that she remembered her mother from happier times.”I don’t want her to be classified as the woman in the boot,” she said.
Nearly three decades after the disappearance of Sydney model, dancer and escort Revelle Balmain, new evidence has come to light that could finally bring closure for her family.
Revelle, 22, disappeared on November 5, 1994, around the Kingsford area with her keys and other personal possessions found scattered on a nearby street.
A coronial inquest in 1999 found she died at the hands of a person or persons unknown.
No one has ever been charged, but after an anonymous tip-off in 2021, the case has been reopened and police are urging the public to come forward with any information that might aid the investigation.
Revelle’s disappearance will be re-examined by the Coroner in February and there is a $1 million reward for information.
Her parents passed away without knowing what happened to their daughter and in October, her sister Suellen Simpson spoke about how Revelle’s disappearance has caused immeasurable grief to her family.
“Not knowing tears you apart limb by limb and your heart crumbles into many hundreds of pieces,” she told The Sun. “It’s infuriating knowing there is someone who knows what happened.”
Wanda beach killings
Nearly 60 years after being murdered and left on the sand dunes of a south Sydney beach, teenagers Marianne Schmidt and Christine Sharrock’s murders remain unsolved.
The 15-year-old girls took a train to Cronulla with Marianne’s younger siblings on January 11, 1965, and spent the day there.
After lunch, the girls walked along the beach, leaving the children on the Wanda Beach sand dunes.
When the girls didn’t return, they made their way home by train. The next day, Marianne and Christine’s bodies were found buried in the hollow of a sandhill.
Many suspects have been investigated over the years, including a young surfer, who was later jailed for child abuse and serial killer Christopher Wilder, who died in 1984 after a six-week murder spree. Police files from the time reveal he was an official suspect.
Police have reopened the case on multiple occasions over the years but no one has been charged.
In 2009, Marianne’s mum Elisabeth died without ever knowing what happened to her.
Her son and Marianne’s brother Hans said in 2014 that Elisabeth had never given up hope that the killer would be discovered.
“She’d always put on a brave face but the impact Marianne’s death had on her was devastating,” he said.
“She said she spoke to Marianne every day and she’d always dream about her.”