Everything You Need to Know About the Erin Patterson Poison Mushroom Case

Erin Patterson poison mushroom case
Martin Keep AFP

Australian woman Erin Patterson has been found guilty of murdering three family members and attempting to murder a fourth with death cap mushrooms served in a seemingly innocent Beef Wellington lunch.

A Fatal Family Meal

After a 10-week trial and six days of jury deliberation, the 50-year-old was convicted on Monday of killing her estranged husband’s parents, Don and Gail Patterson, both 70, and Gail’s sister Heather Wilkinson, 66. Heather’s husband, Ian Wilkinson, 71, was the sole survivor of the fatal July 2023 meal in Leongatha, Victoria.

Red Flags from the Start

The gathering raised suspicions from the start. According to testimony reported by Rolling Stone, Patterson rarely hosted such events, and her estranged husband Simon declined the invitation, texting that he felt “too uncomfortable” to attend. Ian Wilkinson noted that Patterson’s portion was served on a different coloured plate from everyone else’s.

Sudden Illness, Three Deaths

Within hours of the lunch, all four guests became violently ill with vomiting and diarrhoea. They were hospitalised and placed in induced comas. Gail and Heather died on 4th August of multi-organ failure, while Don died the following day after an unsuccessful liver transplant. Ian survived and was discharged in September.

The Mushroom Plot

Prosecutors alleged Patterson deliberately collected death cap mushrooms from rural Victoria, using locations identified on a citizen science website, and prepared them using a dehydrator she purchased in April 2023. This device, which contained her fingerprints and traces of death cap mushrooms, was disposed of at a dump after her guests fell ill.

“I Ate the Same Meal” — But Did She?

While Patterson maintained her innocence, claiming she accidentally mixed poisonous mushrooms with store-bought ones, several pieces of evidence contradicted her story. Despite claiming she ate the same meal, medical tests showed neither she nor her children had ingested anything poisonous. CCTV footage captured her disposing of the dehydrator, and her internet search history included queries about death cap mushrooms.

Motive Still a Mystery

Patterson’s motive remains unclear. Although Simon testified they were on good terms with his parents until 2022 when they began arguing about finances, prosecutors portrayed Patterson as having “two faces.” In Facebook messages, she had expressed frustration with her in-laws’ reluctance to intervene in her declining marriage, writing, “I’m sick of this shit I want nothing to do with them.”

The prosecution identified “four calculated deceptions” in Patterson’s plan, including falsely claiming she had cancer as a pretext for the lunch, secreting lethal mushroom doses in the food, feigning illness herself, and engaging in an elaborate cover-up.

What Happens Next

Patterson now faces life imprisonment, with sentencing to occur at a later date. The case has captivated public attention, spawning at least three podcasts and extensive international media coverage.