Why Australia’s mushroom-murder trial gripped the world

A tiny percentage of Australia’s small population lives outside of its five major cities, in a vast and largely uninhabitable area known as the outback. It has long been thought that Australia’s population is concentrated in cities because of their proximity to the coastline – hardly a surprise, for a country that started off as a penal colony accessible only by ship. But these days, a better explanation for the dwindling population of Australia’s vast interior might be the fear it instills in sane members of society. Because the outback seems to have become a breeding ground not only for Australia’s notoriously dangerous wildlife, but also for murderers and serial killers.

Erin Patterson is the latest name on the list of outback killers. This includes Ivan Milat, whose seven victims between 1989 and 1992 included British backpackers Joanne Walters and Caroline Clarke. Then there was Bradley Murdoch, who murdered Englishman Peter Falconio in 1991. On Monday, Patterson was convicted of murdering three people: the parents and aunt of her estranged husband, Simon Patterson, and the attempted murder of a fourth man, a local rector, who narrowly survived. The crime took place at her home in the small country town of Leongatha, a two-and-a-half hour drive east of Melbourne, in July 2023.

Nearly everything was strange about this case, beginning with the culprit. Patterson hardly fitted the mould of serial killer. She is a middle-aged woman who, at the time of the murders, was quietly raising her two children. Beyond a small alimony dispute with her husband, she had no clear motive for deliberately killing her in-laws and extended family. Nor is this a case involving the usual murder weapons – there was no gun, knife or blunt instrument. Instead, Patterson carried out the murders with what appeared to be nothing more than a homemade beef wellington.

The facts unearthed in Patterson’s eight-week trial read like an Agatha Christie novel, with a dash of Aussie kitsch. Patterson had organised a lunch with her in-laws, Don and Gail Patterson, and two other members of her estranged husband’s family, Heather and Ian Wilkinson. Her husband, Simon Patterson, was invited but refused to attend – a decision that almost certainly saved his life. She faked a cancer diagnosis to coax the guests to her home. She claimed she wanted to discuss how best to break the news of her (non-existent) cancer to her children.

Patterson’s in-laws, retired school teachers who lived in the next town, were walking into a trap. In the weeks before the lunch, Patterson had collected what are known as ‘death cap’ mushrooms in the countryside surrounding Leongatha. To describe the mushrooms as toxic would be an understatement. Half of a cap is sufficient to cause kidney and liver failure, and near-certain death. Patterson prepared the mushrooms in a dehydrator, which police later found in a nearby rubbish tip, before infusing them into her dish.

Unsurprisingly, a vital piece of evidence at Patterson’s trial was the beef wellington itself. She didn’t serve a single ‘log’, as would be standard when hosting guests, but four miniature beef wellingtons – more like sausage rolls. Then there were the colour co-ordinated plates: grey for her guests, and tan orange for herself. This allowed Patterson to avoid the poisoned dishes.

The night of the lunch, all four guests fell violently sick. According to Simon’s testimony, Heather made a comment about Erin serving herself on a different coloured plate. Initially, the Pattersons and the Wilkinsons were taken to local hospitals in Leongatha and Korumburra. By Tuesday, they were on life support at Melbourne’s Austin Hospital, all experiencing organ failure. Gail and Heather died on Friday, Don on Saturday, a week after the lunch. Ian, the sole survivor, remained in hospital for more than a month.

Unsurprisingly, the Australian media descended on Leongatha once the three victims had succumbed to poisoning. Patterson gave a convincing performance: she cried, denied any wrongdoing and insisted that she ‘loved’ her husband’s family like her own. Essentially, she said there had been a terrible accident. Curiously, police consistently refused to rule out her version of events. Months passed and nothing happened. Only in November, more than three months after the dinner, was Patterson charged with three counts of murder and one count of attempted murder.

The rise of digital technology has made it incredibly difficult to get away with murder today. Our search histories and other online activities provide a map of our thoughts. Sure enough, the police discovered that Patterson had skeletons in her online closet, which emerged at her trial, like Banquo’s ghost. She was a regular browser of the iNaturalist website, which had identified the existence of death-cap mushrooms in the countryside near Leongatha in April. Mobile-phone data indicated Patterson’s presence in the exact spot named by the website in the weeks before the lunch.

Then there was the dehydrator, bought by Patterson in the weeks preceding the lunch. This was used to remove the moisture from the death-cap mushrooms she had collected. Police only found the dehydrator because the transaction history on her credit card included a payment to the tip she later tried to bury it in. It all added up to an impregnable circumstantial case against her.

Now that the trial is over, the media have been able to report details that give us a better picture of the accused, without the risk of running afoul of Australia’s strict contempt-of-court rules. It turns out that Erin Patterson was not as squeaky clean as she had led the public to believe. Her previous employment at AirServices Australia had ended under a cloud of financial wrongdoing and accusations – albeit never proven – that she had inserted a razor into a colleague’s banana. In 2004, she lost her driving licence for more than two years after she was convicted for drunkenly crashing an unregistered car, before fleeing the scene. She was also a member of all sorts of odd online groups, including one that centred on an ‘interest’ in Keli Lane, an Australian woman who murdered her child in 1996.

Unsurprisingly, what became known as the ‘mushroom murder trial’ attracted the attention of the world’s media. It had all the ingredients of a gripping Netflix series: the beef wellington used as a murder weapon; the evil lurking beneath the surface of domestic normality; and, in the words of the 19th-century Australian writer, Marcus Clarke, the ‘weird melancholy’ of the outback.

So engrossing have these details been that we have almost forgotten the only ones that matter here – the tragic deaths of Don and Gail Patterson, and Heather Wilkson. They would have been looking forward to their hard-earned retirement in the communities they had given so much to. They had so much more life to live. And Patterson took it all away from them. As ever, no punishment or prison sentence, no matter how long, will ever quite seem enough.

Hugo Timms is an editorial assistant at spiked.