THE relationships between Erin Patterson, her estranged husband Simon, and her in-laws, Don and Gail Patterson, have been an on-going feature of the 23-day ‘mushroom murder’ trial in the Supreme Court at Morwell.
Last Friday, May 30, some ‘Signal’ group chat messages between Don, Gail, Simon and Erin, from November 15 to November 24, 2022, were probed by defence counsel for Erin Patterson, Colin Mandy SC, during the evidence of police informant in the case, Detective LSC Stephen Eppingstall.
This was at the time when the on-again-off-again, mostly friendly, but sometimes “strained” relationship between Erin and Simon Patterson had become “toxic”, in Simon’s evidence, by late October 2022, over child support payments, school fees and medical bills.
There had also been the issue, on October 16, 2022, of what Erin Patterson described as an “afterthought” invite to Gail Patterson’s 70th birthday lunch at the Top Pub in Korumburra, and Simon describing her decision not to go as “ridiculous”.
Back on Day 4 of the trial, Simon Patterson described an exchange between Erin and his parents in a group chat in December 2022 as “extremely aggressive”, prompting him to consider getting a mediator to assist with communication over child support payments.
Under cross-examination by Mr Mandy on May 2 of the trial, after it was suggested that Simon’s child support responsibilities had been assessed at $38-a-month, Simon Patterson acknowledged it was the likely reason why Erin had become so upset.
At $38-a-month, or around $500-a-year in total, Mr Mandy put it to Simon Patterson that it wasn’t going to cover any of the school fees, let alone an anaesthetist's bill, a reference to the costs associated with his son’s knee operation on November 24, 2022.
Mr Mandy started last Friday’s cross-examination of Detective Eppingstall by asking him about Signal messages in February 2022, the first one being between Erin Patterson and Don Patterson, a former maths-science teacher at Korumburra Secondary College, about picking up some schoolbooks and helping the oldest of the Patterson children with his studies.
“We can pick up more books if [he] wants. Also, if he needs help in any subject I might have some competence in, I'm happy to provide it, probably in Jitsi (free video conferencing software),” said Don Patterson.
“Thank you so much… I think [he] would absolutely love a Jitsi session for maths. They're working through algebra, and he says it's one topic that he finds a little tricky, so he actually mentioned last night that he thought a Papa session on algebra would really help him about now,” said Erin Patterson in response.
There was also an exchange over some new concerns about COVID, with Erin thanking Don for the use of Gail’s blood/oxygen monitor.
Mr Mandy then moved to questions about group chat messages between Don, Gail, Erin, and Simon between November 15 and 24, 2022.
The first one was on November 15, 2022, between Gail and Erin: “Hi Erin. Thank you for the two slices you made for Sunday's arvo tee. Very thoughtful of you. We are very thankful for the mild weather we had. Sorry to hear you're not feeling well. Hope a good night's sleep helped and you're feeling better today.”
Erin responded saying thanks for the kind message and that she still felt nauseous with a headache, Gail contacting her three days later to ask how Erin was feeling.
On November 24, 2022, there was an exchange over the Pattersons’ teenage son having a knee operation that day.
“Could you please tell [him] we are all praying all goes smoothly for his knees today and that he will know God's peace. Safe travels xo, Nana and Papa.”
There followed a brief exchange, then a longer message from Erin later in the afternoon that the surgery had gone well, which was picked up on by Simon.
“Good news about the surgery. Thanks for that update, Erin,” said Simon, going on to comment about some other medical issue referred to by the doctors.
Gail Patterson was also appreciative of the news.
“Thanks for letting us know, Erin, sounds good. Thankyou God, and the doctors,” said Gail.
Mr Mandy also made reference to an exchange on Mother’s Day, May 8, 2023, between Erin Patterson and Gail Patterson.
“Happy Mother's Day, Erin. May God bless you. Love Don and Gail.”
Erin replied: “Thanks Gail. Happy Mother's Day to the best mum-in-law anyone could ask for, xxoo.”
Gail responded: “Very kind of you xo.”
But it wasn’t all plain sailing with the evidence of senior digital forensics officer at the Victoria Police cybercrime department, Shamen Fox-Henry painting a different picture.
On May 22, 2025, prosecutor Jane Warren questioned Mr Fox-Henry about an exchange between Erin Patterson and some of her Facebook friends via Messenger about Erin’s efforts to get Simon’s parents to intervene in the child-support dispute.
“I wonder if they've got any capacity for self-reflection at all? I mean clearly the fact that Simon refuses to talk about personal issues in part stems from the behaviour of his parents and how they operate. According to them they have never asked him what's going on with us, why I keep kicking him out, why his son hates him etc,” Erin Patterson is alleged to have said on December 6, 2022, under the social media name “Erin, Erin, Erin”.
“It's too awkward or uncomfortable or something. So, that's his learned behaviour. ‘Just don't talk about this shit’.”
Erin is also alleged to have said that Don called her to say that if she prayed with Simon, and withdrew the child support claim, a solution to the impasse could easily be found.
“My head nearly exploded, and I was like what?” Erin, Erin, Erin told her friends’ group.
Don contacted her later to ask her to ignore his earlier remarks, saying that he and Gail didn’t want to get involved in financial matters.
Erin told her friends that she thought Simon asking her to withdraw the child support claim was unconscionable and wrong.
She said she messaged Don to say that while she appreciated it was uncomfortable and awkward for them to hear, she wanted to copy them into the discussion about child support because Simon needed to be accountable for the decisions he is making “that are hurting his children” and their grandchildren.
After a message from Don suggesting they pray together, Erin again messaged her friends’ group.
“I'm sick of this shit, I want nothing to do with them. I thought his parents would want him to do the right thing, but it seems their concern about not wanting to feel uncomfortable and not wanting to get involved in their son’s personal matters are overriding that, so fuck’em.”
There were more references to school fees, the choice of an alternative school to the faith-based school the children were attending and child support.
“Simon wants to walk away from his responsibilities too. Well, that's his choice. Maybe it's easier if he's not involved in even paying their school fees. It means I can choose their school all by myself and don't have to refer to him.”
The dispute about changing schools was ultimately left unresolved. In the interview with police on August 5, 2023, Erin Patterson revealed an interest in selling the Mt Waverley house and buying one closer to the new school.
The squabbles over child support payments, school fees, doctor’s fees and the like were against a backdrop of Erin Patterson being very generous with her money, especially the inheritance she received from her grandmother, well after separation in 2015, putting Simon’s name on the title for the homes she had purchased in Mt Waverley and Leongatha, while also lending “hundreds of thousands of dollars” to three of Simon’s siblings to buy their homes.
Whether the relationship between Erin Patterson, her husband Simon and his parents Don and Gail Patterson has an impact on the outcome of the trial is a matter for the jury.
But in her opening remarks, on Day Two of the trial, Crown Prosecutor Dr Nanette Rogers offered the prosecution’s general view about motive.
“I want to talk to you about motive,” she said to the jury.
“You might be wondering, now, why would the accused do this? What is the motive? You might still be wondering this at the end of this trial,” she said.
“As I’m sure His Honour will direct you towards the end of the trial, motive is not something that has to be proven by the prosecution.
“You do not have to be satisfied what the motive was or even that there was one. The prosecution will not be suggesting that there was a particular motive to do what she did.”
Erin Patterson has pleaded not guilty to three charges of murder and one of attempted murder arising out of a family lunch of beef Wellington including death cap mushrooms at her Leongatha home on Saturday, July 29, 2023, maintaining that while she did lie to police about foraging for mushrooms, she denies ever deliberately setting out to find death cap mushrooms.
Mrs Patterson says that what happened on that day was a tragedy and a terrible accident.
The case continues into its final days in the Supreme Court at Morwell this week.