Case overview
On January 11, 1965, Marianne Schmidt and Christine Sharrock, both 15, were found dead in the sand dunes near Wanda Beach, south of Sydney. The case became one of Australia’s most scrutinized unsolved murders, marked by early suspect focus, conflicting witness accounts, and decades of DNA testing that have yet to produce an arrest.
The victims and the final day
Marianne Schmidt and Christine Sharrock left their homes in West Ryde on the morning of January 11, 1965. They told their families they were going to Cronulla Beach but traveled instead to Wanda Beach, a more isolated stretch of coastline south of Sydney known for its dunes.
The girls were last seen alive near the shoreline in the early afternoon. Witnesses reported seeing two teenagers matching their descriptions walking toward the dunes. By late afternoon, their bodies were discovered partially buried in sand.
Both had been sexually assaulted and stabbed multiple times. Their belongings were scattered nearby. The scene indicated a sudden, violent attack.
The early investigation
Police determined the girls had been killed within hours of arriving. The remote location and absence of immediate witnesses complicated efforts to identify a suspect. Investigators canvassed the area and interviewed beachgoers, but no clear leads emerged in the first days.
Forensic evidence recovered from the scene included biological material, but DNA profiling would not be available for decades. The case drew significant media attention and public pressure.
Within weeks, detectives identified Derek Ernest Percy, a teenager who had been in the area at the time, as a person of interest. Percy was later convicted of the 1969 murder of 12-year-old Yvonne Tuohy in Victoria and became a suspect in multiple unsolved child homicides across Australia.
Suspect scrutiny and unresolved questions
Percy was never charged in connection with the Wanda Beach murders. He denied involvement and was never placed at the scene through physical evidence. His presence in the general area at the time, combined with his later conviction, kept him under investigative focus for decades.
Percy died in 2013 while imprisoned. His death closed one investigative avenue but did not resolve the question of his involvement. Police continued to describe him as a person of interest, though no evidence had been sufficient to support charges.
In the years following his death, investigators revisited the case using advances in forensic technology. DNA samples collected from the crime scene were reanalyzed multiple times. Results were inconclusive, and no match was found in national databases.
Other suspects were considered over the years, but none were publicly named. The investigation remained active, with periodic reviews and attempts to locate new witnesses or evidence.
The role of forensic evidence
The preservation of biological evidence from the 1965 crime scene allowed for repeated testing as forensic methods improved. In 2012, New South Wales police confirmed that DNA samples had been resubmitted for analysis using updated techniques. The results did not produce a usable profile that could be matched to any individual in the system.
Investigators also examined the possibility of familial DNA matching, a method that identifies relatives of potential suspects through partial genetic matches. This approach yielded no actionable leads.
The limitations of the original crime scene processing, combined with the degradation of biological material over time, have restricted the usefulness of forensic evidence.
Witness accounts and timeline gaps
Witness statements collected in the days after the murders provided a general timeline but left key gaps. Several beachgoers reported seeing two teenage girls near the dunes in the early afternoon. Others described a young man in the area around the same time, but descriptions varied and no composite image led to identification.
One witness reported seeing a person leaving the dunes in a hurried manner, but the individual was never located. Another account mentioned a vehicle parked near the beach access road, but the make and model could not be confirmed.
These accounts have been revisited multiple times, but inconsistencies and the passage of time have prevented them from yielding new leads.
Public appeals and cold case reviews
New South Wales police have issued public appeals for information at several points over the past six decades. The 50th anniversary of the murders in 2015 prompted renewed media coverage and a request for anyone with knowledge of the case to come forward. No significant new information resulted.
The case has been the subject of multiple cold case reviews, including examinations by the Unsolved Homicide Unit. Each review has reaffirmed the challenges posed by the age of the case, the limitations of the original investigation, and the lack of definitive forensic matches.
Investigators have also explored potential links to other unsolved crimes in the region during the same period. No confirmed connections have been established.
Current status
The Wanda Beach murders remain officially unsolved. The case is classified as open, and investigators continue to accept tips and review any new evidence that emerges. Advances in forensic science offer the possibility of future breakthroughs, but no active suspect has been publicly identified since Percy’s death.
The families of Marianne Schmidt and Christine Sharrock have maintained hope for resolution, but the passage of time has reduced the likelihood of witnesses coming forward or new physical evidence being discovered.
Where to look next
- Documentary: “Australian Crime Stories: Derek Percy” (Nine Network)
- Book: “The Fishermen” by Debi Marshall
- Podcast: “Australian True Crime” (Casefile Presents)
