Christine Sharrock & Mary Schmidt

On Monday, January 11, 1965, a scorching summer day, a group of teenagers from the Canterbury-Bankstown area of Sydney traveled by train to Cronulla Beach in the city's south. Among them were Christine Sharrock and Mary Schmidt, both fifteen years old and close friends. The group spent the morning swimming and sunbathing before Christine and Mary wandered south along the beach toward the more isolated sand dunes of Wanda Beach.

When the girls did not return, their friends initially assumed they had caught an earlier train home. It was not until the following morning that fishermen discovered their bodies among the sand dunes. Both girls had been brutally stabbed multiple times—Christine had been stabbed in the chest, and Mary in the back. There was evidence of sexual assault. The attack appeared frenzied, and the remote location of the dunes meant there were no witnesses.

The investigation became one of the largest in Australian history at that time. Over 200 detectives worked the case, and more than 250,000 people were interviewed or eliminated from inquiries. A man was seen near the dunes that day, described as 'European-looking' with dark hair, but he was never identified. Multiple suspects were investigated over the decades, including a man later convicted of other violent crimes, but no charges were ever laid in connection with the Wanda Beach murders.

New South Wales Police have periodically reviewed the case with advances in DNA technology, most recently in 2016. While some DNA was recovered from the crime scene, it has not been matched to any individual in databases. The case remains one of New South Wales' most notorious unsolved crimes and a defining moment in the loss of innocence in Australian beach culture.