An Australian mother who murdered her estranged husband’s parents and aunt by feeding them a beef wellington laced with poisonous mushrooms has been jailed for a minimum of 33 years.

Erin Patterson, 50, lured her former parents-in-law Don and Gail Patterson, both 70, and Gail Patterson’s sister, Heather Wilkinson, 66, to lunch at her home in Leongatha, Victoria, on 29 July 2023.

Mrs Wilkinson’s husband, Reverend Ian Wilkinson, also ate the meal, which was served alongside mashed potatoes and green beans, but survived after receiving a liver transplant and spending months in hospital.

Patterson, a mother-of-two, had made the pastry dish with deadly death cap mushrooms, also known as amanita phalloides.

Image:
Pic: AP

Her trial in Morwell, southern Australia, heard that Patterson fabricated a cancer diagnosis to use as an excuse not to invite her children, pretending to want to discuss how to break the news to them after the meal.

The four guests fell ill immediately after eating her food. Mrs Wilkinson and Mrs Patterson died on 4 August, and Mr Patterson a day later.

Reverend Wilkinson spent seven weeks in hospital but survived.

Reverend Ian Wilkinson arrives at court. Pic: Reuters
Image:
Reverend Ian Wilkinson arrives at court. Pic: Reuters

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More details of mushroom case revealed

In his victim impact statement, he said the poisoned food meant he had to have a liver transplant and was left feeling “half alive”.

Patterson, who maintains her innocence and that she poisoned her victims by accident, also invited the father of her children, Simon Patterson, to the fatal meal.

Simon Patterson outside of court in May. Pic: AP
Image:
Simon Patterson outside of court in May. Pic: AP

He declined the invitation.

In his victim impact statement, Mr Patterson said of the couple’s children: “The grim reality is they live in an irreparably broken home with only a solo parent, when almost everyone else knows their mother murdered their grandparents.”

In July, Patterson was found guilty of murdering Don and Gail Patterson, and Heather Wilkinson, and attempting to murder Ian Wilkinson.

What makes death cap mushrooms so lethal?

The death cap is one of the most toxic mushrooms on the planet and is involved in the majority of fatal mushroom poisonings worldwide.

The species contains three main groups of toxins: amatoxins, phallotoxins, and virotoxins.

From these, amatoxins are primarily responsible for the toxic effects in humans.

The alpha-amanitin amatoxin has been found to cause protein deficit and ultimately cell death, although other mechanisms are thought to be involved.

The liver is the main organ that fails due to the poison, but other organs are also affected, most notably the kidneys.

The effects usually begin after a short latent period and can include gastrointestinal disorders followed by jaundice, seizures, coma, and eventually, death.

Previous poisoning attempts left husband ill

Following the guilty verdicts, more details of the case were revealed.

Mr Patterson said he had rejected the lunch invite “out of fear” as he believed his former partner had tried to poison him three times before.

After they separated in 2015, he stopped eating any food she had prepared, having become seriously ill after meals cooked by her.

Death cap mushrooms. Pic: iStock
Image:
Death cap mushrooms. Pic: iStock

Reverend Wilkinson also revealed he and the other three guests were served their food on large grey dinner plates, while Patterson served her portion on a smaller, tan-coloured plate.

The nine-week trial attracted intense interest in Australia – with podcasters, journalists and documentary-makers descending on the town of Morwell, around two hours east of Melbourne, where the court hearings took place.