One word on a tax return set off lethal chain of events

When Leongatha father Simon Patterson put on his tax return in 2022 that he was separated, it set off a lethal chain of events.

The relationship between him and his estranged wife, Erin Patterson, deteriorated well before a mushroom lunch killed three church parishioners as the pair quarrelled over child support payments and where their children would go to school.

Erin Patterson arrives at court in Morwell in May.Credit: AFP

“He quit his job. I was getting $38 per month child support,” Erin told a government employee in the aftermath of the lethal lunch that killed Don and Gail Patterson and Heather Wilkinson.

“I asked for reassessment from child support. Every time he got really angry. When it went up to $473 per month ... he cancelled his direct debits for his [children’s] activities – stopped paying private health cover.

“I changed the kids’ school and enrolled them in [another]. I did not tell him, but he found out and kept calling the school, demanding they put him on the enrolment. He started a campaign against the school … angry they enrolled the children without his permission.”

The inner workings of the Patterson family relationships would be on display during Erin Patterson’s triple-murder trial. The jury was told about how Simon and Erin got together, their wedding and an eight-year marriage rocked by repeat separations and reconciliations. They parted permanently in 2015.

Simon told the court their split had been friendly and they shared custody of the children, went on family holidays together and organised to divide their assets without intervention from lawyers.

But while dropping his children back to Erin Patterson’s Gibson Road home in Leongatha, he said, he became aware there was an issue.

It was late October or November in 2022, he recalled, when his estranged wife pulled him aside for a chat. She sat in the car with Simon and said she had discovered that his tax return for the previous financial year noted they were separated.

“Before that, we hadn’t gotten the government involved in the fact we were separated at all before,” Simon said. “She said that it mattered, I think, for the family tax benefit, something of that nature. And so, she would be obliged to claim child support off of me, which had never happened before.”

Simon told the court his tax status was changed as a result of a miscommunication between him and his accountant. He said Erin rejected his efforts to revert it.

From then on, Simon said, communication became more functional and less “chatty”.

“That was probably the first thing that made me feel that there was a substantial change in our relationship, that before that, our habit for years was to message each other a lot, in a chatty way, and the chatty nature of it pretty much stopped,” he said.

He said that a few weeks later, Erin applied for child support. She was also keen for him to sign a form stipulating that they would each pay half of the children’s school fees.

Simon Patterson outside the court in early May.Credit: Jason South

However, Simon told Erin he had been advised by government staff not to do so, as the school fees would be covered in the child support payments.

“I’m sure she was very upset about that,” Simon told the jury.

About seven months later, Simon Patterson’s parents and aunt and uncle lay critically unwell in the Austin Hospital from death cap mushroom poisoning.

The prosecution case was the killer had lured the family to lunch at her home under the guise of telling them she had cancer. Medical records would later show this was never the case.

It wouldn’t be until November 2023, four months after the lunch, that police would make an arrest. Erin Patterson was charged with three counts of murder and one of attempted murder.

Other charges – three counts of attempted murder relating to estranged husband Simon Patterson – were dropped on the eve of the high-profile murder trial.

During the trial, the jury heard from more than 50 witnesses. They included the surviving lunch guest Ian Wilkinson, Simon Patterson, other Wilkinson and Patterson family members, medical witnesses and online friends of Erin Patterson.

The jury also heard from mushroom and toxin experts, the manager of a local tip where Erin’s dehydrator – laden with death cap toxins – was found dumped, alongside a phone tower expert, health officers and homicide squad detectives.

During the trial, the jury heard Erin Patterson had lied about having cancer to lure family members to her home for lunch on July 29, 2023, and about getting rid of the black Sunbeam food dehydrator in the e-waste section of the tip in the aftermath of the fatal meal.

When the lunch guests arrived, the jury heard, Erin served beef Wellington on different coloured plates to her own to deliberately poison them.

“I noticed Erin had put her food on a different plate to us. Her plate had colour on it, I wondered why that was,” Heather Wilkinson told family before she died.

Hours after the lunch, all four guests fell ill. Don and Gail Patterson and Heather Wilkinson died at the Austin Hospital on August 4 and 5, while Ian Wilkinson survived after a lengthy stay in hospital.

Erin Patterson’s Leongatha home, the scene of the fatal lunch.Credit: Joe Armao

Erin Patterson had gone to Leongatha hospital complaining of not feeling well, but left after telling staff she was not prepared to stay, sparking a triple-zero call to police to try to find the now 50-year-old. She later returned to hospital and was found to be suffering from gastro-like symptoms but no significant illnesses.

The jury also heard that in the months leading up to the lunch, Erin posted messages in a Facebook chat group about dehydrating mushrooms, including sharing in the chat that she had bought a food dehydrator. She posted photos of the new appliance on her kitchen bench.

By this point, Erin Patterson’s ill will towards her estranged husband was extending to her in-laws.

She also told her online friends, using an account name of Erin Erin Erin, that Simon Patterson was a “deadbeat” father, and Don and Gail Patterson were “a lost cause” the year before the lunch.

She complained that Simon Patterson had refused to talk about his side of a shared issue, after which his father, Don, had said he was unable to adjudicate between the pair, instead urging them to get together and pray.

“This family I swear to f---ing god,” the post read.

“I said to him about 50 times yesterday that I didn’t want them to adjudicate. Nobody bloody listens to me, at least I know they’re a lost cause.”

As the conversation continued, the court heard, more posts were made including some discussing difficulties in obtaining child support, and suggestions from Simon’s family that she withdraw her claim.

In one message, Erin wondered if Simon Patterson had any capacity for self-reflection, and said his refusal to talk about personal issues appeared to be a “learned behaviour” from his parents to not “talk about this shit”.

She complained he “needs to be accountable” for his decision-making that was hurting their children.

“I’m sick of this shit I want nothing to do with them,” the post read. “F--- them.”

“I don’t need anything from these people.”

“Simon wants to walk away from his responsibilities. If he wants them to go to a private Christian school, he can help pay for it.

“His mum was horrified that I had claimed child support. Why isn’t she horrified that her son is such a deadbeat that I had no choice but to claim?”

Phone tower data aired in court suggested Erin Patterson was in the Loch and Outtrim areas, in South Gippsland, soon after posts were made on a citizen scientist website about sightings of death cap mushrooms growing in the wild.

After three of the lunch guests died, police searched her home, discovering one of her phones was factory-reset a number of times over a 48-hour period, including remotely the day after the police raid. Another phone was never found.

Erin’s defence team, led by Colin Mandy, SC, maintained the poisoning was nothing more than “a tragedy and a terrible accident”.

On day one of the trial, he said his client admitted, for the first time, that she did forage mushrooms but denied ever deliberately seeking out the death cap variety.

Mandy said the defence case was that Erin Patterson panicked because she was overwhelmed that four people had become ill because of the food that she’d served to them.

He also maintained his client never feigned any illness and instead panicked.

On Monday, the jurors emphatically rejected that version of events with their guilty verdicts.

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