Wanda Beach, Australia
On January 11th, 1965 the bodies of Marianne Schmidt and Christine Sharrock, both aged 15, were found partially buried on Wanda Beach. The murders did not appear to be premeditated – there was evidence of rape and blunt force trauma on both victims, though the brutal stabbing was determined to be cause of death. The investigation was the most widespread in Australian history at the time, interviewing nearly 7,000 people in connection with the case, but it remains unsolved to this day.