The jury in the trial of an Australian woman accused of murdering her estranged husband’s parents and an aunt by serving them poisonous mushrooms has begun deliberations.
Mother-of-two Erin Patterson, 50, is charged with the 2023 murders of her former parents-in-law, Don and Gail Patterson, both 70, and Gail Patterson’s sister, Heather Wilkinson, 66, along with the attempted murder of Reverend Ian Wilkinson, Heather’s husband.
The prosecution alleges she served guests beef wellington knowing it contained deadly death cap mushrooms, also known as Amanita phalloides.
Patterson denies all the charges, claiming the deaths were a “terrible accident”.
The jury began deliberations on Monday after an intense nine-week trial at the Supreme Court of Victoria in which Patterson appeared in the witness box, as did the sole survivor of the alleged poisoning.
Here’s what you need to know about the case.
An unexpected invitation
Patterson invited the four alleged victims for lunch at her home in Leongatha, a small town in Melbourne, on 29 July 2023.
Her estranged husband, Simon Patterson, was also invited but didn’t attend. Text messages read out in court revealed Patterson found his decision not to come “really disappointing” as she had spent time and money preparing the “special meal”.
He said he had listed them as financially separated on a tax return, which triggered a series of child support payments that meant he would no longer pay their two children’s private school fees directly, he told the court.
Speaking to the court through tears, Mr Patterson said: “I was sure she was very upset about that.”
Reverend Wilkinson said he and his wife were surprised by the invitation, telling the Australian Broadcasting Corporation (ABC): “There was no reason given for the lunch, and I remember talking to Heather wondering why the sudden invitation.”
But he said the pair were “very happy to be invited”.
Patterson’s daughter, according to ABC, told the court that her mother organised a trip to the cinema for her and her brother in advance of the lunch.
Sole survivor gives details about the lunch
Reverend Wilkinson told the court Heather and Gail offered to help plate up the food, but Patterson rejected the offer.
Each plate had a serving of mashed potatoes, green beans and an individual beef wellington.
Patterson said the mushrooms were a mixture of button mushrooms from a supermarket and dried mushrooms bought at an Asian grocery store several months ago, which were in a hand-labelled packet.
Reverend Wilkinson said the four guests were given large grey dinner plates, while Patterson ate from a smaller, tan-coloured plate.
He said he remembered his wife pointing this out after they became ill.
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 include gastrointestinal disorders followed by jaundice, seizures, coma, and, eventually, death.
The reverend said he and his wife ate their full servings, while Don ate his own and half of his wife’s.
Reverend Wilkinson said that after the meal, Patterson fabricated a cancer diagnosis, suggesting the lunch was put together so that she could ask them the best way to tell her children about the illness.
The prosecution said she did this to justify the children’s absence.
The defence does not dispute that Patterson lied about having cancer.
When asked why she lied about her health, Patterson told the court it was partly to elicit sympathy from her husband’s relatives, as she felt they were growing apart.
“I didn’t want their care of me to stop, so I kept it going. I shouldn’t have done it,” she said, adding: “I did lie to them.”
Defendant wanted to serve ‘something special’
While on the stand at the beginning of June, Patterson said she might have accidentally included foraged mushrooms in the fatal lunch.
She said she brought expensive ingredients and researched ideas to find “something special” to serve. She said she deviated from her chosen recipe to improve the “bland” flavour.
However, she denied that a series of photos showing mushrooms placed on weighing scales in her kitchen was evidence she had been measuring a “fatal dose” to serve to her lunch guests.
Prosecutor Nanette Rogers asked: “I suggest that you were weighing these death cap mushrooms so that you could calculate the weight required for the administration of a fatal dose for one person. Agree or disagree?”
“Disagree,” Patterson replied.
The mother of two said she began foraging for mushrooms around the towns of Korumburra and Leongatha during the COVID lockdowns in 2020 and would use a food dehydrator to dry and preserve them.
Prosecutors earlier claimed the defendant denied ever owning a food dehydrator, but police traced one owned by her to a nearby dump. It was later found to contain death cap mushrooms.
Two mobile phones she owned were also reset to factory status three times.
Patterson told the court she disposed of the dehydrator before a visit from child protection, who were investigating her living arrangements. She said the phones were wiped because she panicked during the police investigation.
“I was scared of the conversation that might flow about the meal and the dehydrator,” she said.
“I was scared they would blame me for it, for making everyone sick. I was scared that they would remove the children.”
Patterson talks through tears
Lawyer Mr Mandy also questioned Patterson about a series of expletive-laden messages she sent to friends about the Patterson family.
“I wish I’d never said it. I feel ashamed for saying it and I wish that the family didn’t have to hear that I said that,” Patterson told the court about the messages.
Talking through tears, she added: “I was really frustrated with Simon, but it wasn’t Don and Gail’s fault.”
The court previously heard the relationship between Patterson and her estranged husband deteriorated shortly before the alleged murders due to a disagreement over child support.
Patterson’s children ‘ate leftovers after guests went to hospital’
All four alleged victims fell ill and were experiencing severe vomiting and diarrhoea by midnight on the day of the lunch.
Police previously said the symptoms of all four of those who became ill were consistent with poisoning from death cap mushrooms, which are responsible for 90% of all toxic mushroom-related fatalities.
Patterson says she also became ill hours after eating the meal.
Her daughter, according to the ABC, told the court she remembers Patterson telling her she had diarrhoea that night.
Patterson claims she and her children ate leftovers from the beef wellington on the same day. Her daughter told the court she remembered this, and that her mum didn’t eat much because she was still feeling unwell.
The mum said she scraped the mushrooms off the plates in advance because she knew her children didn’t like them.
Patterson went to hospital two days after the lunch, where she initially discharged herself against medical advice, the court was told.
A nurse at the hospital where she was treated told the court she “didn’t look unwell like Ian and Heather”, who were at the same hospital.
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Gail and Heather died on Friday 4 August 2023, while Don died a day later.
Reverend Wilkinson spent seven weeks in hospital but survived.
Days after the deaths, police opened a homicide investigation and confirmed Patterson was a suspect. She was charged on 2 November 2023.
What must the jury decide?
The jury is tasked with deciding whether or not Patterson meant for her guests to die during the lunch.
The aim of the court case is not to determine motive, but prosecutors suggested a deteriorating relationship between Patterson and her estranged husband, as well as her exasperation with her former in-laws, which she expressed to friends on social media months before the deaths.
The defence say she had a positive and loving relationship with her lunch guests and had no motive to kill them.
She faces life in prison if convicted.
What is happening now?
A 14-member jury heard the case, but 12 were selected by ballot on Monday to decide the verdict.
The jury remains sequestered, meaning they will stay together in court-appointed accommodation until they reach a unanimous decision.
They cannot return a verdict outside of the court’s sitting hours and members are barred from discussing the case outside the jury room – even with each other.
Sequestering, which aims to stop juries being influenced by outside factors, is rare in Australian courts, but Patterson’s case has been incredibly high-profile, with national news outlets posting daily blogs about court proceedings.
