Shocking Australian Mushroom Murder Case EXPLAINED
Australian Mushroom Murders Explained
Welcome to WatchMojo, and today were examining the mushroom poisoning trial thats shocked the world.
On July 29th, 2023, Erin Patterson, resident of Leongatha, Australia a small town close to Melbourne poisoned four of her relatives with death cap mushrooms. These mushrooms are most often found in Europe, but have spread around the world and do now grow natively in Australia. Almost two full years later, on July 7th, 2025, Patterson was found guilty of three counts of murder and one count of attempted murder.
The victims were her mother- and father-in-law, Gail and Don Patterson; Gails sister Heather Wilkinson, and Heathers husband Ian Wilkinson. Her estranged husband, Simon, was also going to attend the lunch where they were poisoned, but texted Erin the night before saying he felt too uncomfortable to go. Erin wasnt happy, stressing in messages that have been released throughout the trial how much effort she put into making beef wellington for everybody. But Simon still didnt attend the lunch, even though it was ostensibly to talk about some serious health issues Erin was facing.
Because of the nature of the lunch discussing Erins recent ovarian cancer diagnosis, specifically she and Simons two children were, she alleges, sent to the movie theater, and were out of the house. She served the individual beef wellingtons, made from steaks, and discussed her cancer diagnosis, only for Gail, Don, Heather, and Ian to become ill the next day. They were admitted to hospital, and quickly, doctors began to be concerned for the wellbeing of Erin and the children, too. Erin had also supposedly eaten the beef wellingtons, and said that the children had had some leftovers but, crucially, shed scraped off the mushrooms before giving them to the kids because, she claimed, they didnt like mushrooms. Doctors desperately wanted Erin and the kids to be admitted, but she refused despite turning up at hospital and telling them that she was also suffering from stomach pains. Within six days, Gail, Don, and Heather had passed away in hospital, while Ian managed to survive after having a liver transplant. Don also received a liver transplant but his injuries were too severe.
By August 14th, a criminal investigation was opened, and Erins erratic behavior began to look very suspicious indeed. There were her claims that shed also eaten the food but hadnt become sick, not to mention the disposal of a food dehydrator. She claimed to police that the food dehydrator was unrelated to the lunch and that the mushrooms shed used in the beef wellington had been bought months previously at a supermarket. Shed also lied to police about having a food dehydrator at all, at one point claiming she didnt, despite posting pictures of the dehydrator and some mushrooms shed dehydrated in it on Facebook. And she was unable to produce the names of any of the stores she alleged she used to buy mushrooms, at one point saying she bought mushrooms from an Asian supermarket and at another saying she bought a forest mix of mushrooms from somewhere in Melbourne.
Erin was ultimately arrested in November 2023 and charged with three counts of murder and five counts of attempted murder, with the trial eventually beginning in May 2025; she pleaded not guilty to all charges. Some of the attempted murder charges were later dropped. The trial ended up running longer than planned and Patterson herself did testify, along with various investigators, the survivor Ian, Simon Patterson, and some expert witnesses. The prosecution outlined the various lies and deceptions Patterson had engaged in immediately following the lunch, including disposing of the food dehydrator. The dehydrator was eventually found by police after following CCTV evidence, with footage of a woman disposing of it in a landfill. The food dehydrator tested positive for toxins found in death cap mushrooms. It also had Erins fingerprints on it. She said that the reason she threw away the dehydrator WASNT that she was disposing of evidence, but that Simon, in hospital, allegedly accused her of poisoning his parents intentionally, and she panicked and got rid of it.
But more evidence emerged, including CCTV and phone records tracking Erins movements, showing that multiple times shed driven to visit areas of Australia where death cap mushrooms are known to grow in the wild. Detectives seized her computer and phone and found that shed accessed images of death cap mushrooms on the website iNaturalist. This website is for hobbyists who post about interesting plants, animals, fungi, and so on, that theyve seen recently, and where they were including death cap mushrooms. An expert mycologist testified and said that death cap mushrooms only grow in the wild, so the chances of any commercially-grown mushrooms becoming accidentally contaminated is slim to none; death cap mushrooms just wont grow in those conditions. There was also an investigation carried out into local stores to find out whether any of their products were contaminated with lethal mushrooms, and police found no evidence of this. Finally, though they had some phone records, the phone itself had been factory reset by Erin four times after the incident. The jury agreed that Erin had foraged for the mushrooms herself. She later testified to this effect, but said that she was a regular forager of mushrooms, and had foraged for them many times before the fatal incident. It was also calculated that she may have been using as much as 600 grams of death cap mushrooms, or 20 ounces, which is a LOT of poisonous mushroom to have been added accidentally.
There was another key detail that emerged in court, too: the orange plate. Ian Wilkinson testified that during the lunch, Erin had eaten on an orange plate, while the other four guests had eaten from gray plates. These gray plates werent found during searches of the property, so couldnt be tested. It also came out that Erin did not, in fact, have ovarian cancer, or any type of cancer, and had been lying about this. She herself said that she was actually going to imminently undergo gastric bypass surgery in an effort to lose weight, and had lied to her in-laws because she felt embarrassed. Finally, there was minimal medical evidence that Erin HAD fallen ill in the days following the poisoning like she claimed, other than her own word, as she initially refused any tests and when she WAS tested, there was no trace of poison.
Given the volume of evidence against Patterson, her constant lies, and her contradictory testimony in the court room, nobody was surprised when the jury returned a verdict that she was guilty on all counts: three counts of murder for the deaths of Gail Patterson, Don Patterson, and Heather Wilkinson, and one count of the attempted murder of Ian Wilkinson.
But one question remains: why? Why did she poison her relatives? The court heard evidence that her relationship with her in-laws was strained, and that there were disputes about the children, their taxes, and other finances between her and Simon, including many aggressive messages sent between them. Their son also testified via pre-recorded video and said that the relationship between his parents was not good. Erin claimed that the lunch was intended to help family relationships, but its clear from the verdicts: Erin organized this lunch to poison her in-laws, including, presumably, Simon, who was also invited, and sent the children away to the cinema to avoid the risk of them also getting ill. Evidence from her electronic devices suggested that shed researched death cap mushrooms, foraged for them specifically, measured out fatal doses, ensured that she herself didnt accidentally eat a tainted beef wellington by using a different plate, and tried to cover up the crimes. Interestingly, the prosecution didnt try to suggest a motive for Erin in court.
Will Erin ever explain why she did it, and how she convinced herself she would get away with her crime? Considering she apparently wants to appeal the verdicts, this seems unlikely. For now, Australias trial of the century has wrapped up, and the mushroom murders have been solved.
And that was our deep-dive into the Australian mushroom cook killer. Were you following the case from the start, or did you not hear about it until the verdict was reached? Let us know.
