In 1986 on Phillip Island, a young woman called Beth Barnard was savagely murdered and her boyfriend’s wife, Vivienne Cameron, went missing. The police immediately jumped to what they thought was the obvious conclusion: in a jealous rage, Vivienne had killed Beth and then herself. Vivienne’s body was never found.

But Vikki Petraitis wasn’t convinced. The official line didn’t explain all the evidence, and it certainly didn’t seem like the behaviour of a mother with two small boys. Fascinated by both the case and the bias it revealed in investigators, Petraitis wrote her first true-crime book about the murder, with Paul Daley, and decades later made a podcast on the case. Both brought new evidence and testimony to light, and asked questions that were not asked at the time.

To mark the fortieth anniversary of Beth’s murder and Vivienne’s vanishing, Petraitis brings together all her discoveries and true-crime experience in a brilliant forensic investigation into what happened all those years ago, and why.

In this episode Gregory Dobbs chats to Vikki Petraitis about why she has returned to this forty-year-old cold case, about her insights into the Philip island community, and why she is not convinced that the police investigation had reached a reasonable conclusion.