On 11 January 1965, 15-year-old best friends, Marianne Schmidt and Christine Sharrock were overwhelmed and slaughtered in the sandhills behind Sydney's Wanda Beach. Not only had the killer struck in a public area and during the summer school holiday break, but he'd done it in broad daylight. Despite the brazenness of the act, several police investigations and their ostensibly ongoing inquiries have failed to bring the killer to justice. Why...