'Two faces': Online posts show mushroom cook's duality

Erin Patterson denies having "two faces" when it comes to her relationship with her former in-laws, who died after eating a toxic beef lunch she cooked them.

The 50-year-old mother has pleaded not guilty to the murder of Don and Gail Patterson, 70, and Gail's sister Heather Wilkinson, 66, along with the attempted murder of Ian Wilkinson.

She denies deliberately poisoning her lunch guests on July 29, 2023 by serving them death cap mushroom-laced beef Wellingtons.

Patterson, giving evidence for the fifth day in her Supreme Court trial in regional Victoria, was questioned about her relationship with her in-laws today.

Crown prosecutor Nanette Rogers SC suggested she was angry with them because they had taken her estranged husband Simon Patterson's side in a dispute between the pair over child support and schooling, which she denied.

"I suggest you didn't love them," she put to Patterson.

"That's not true," Patterson said.

"I suggest you had two faces – a public face appearing to have a good relationship with Don and Gail," the prosecutor said.

"I had a good relationship with Don and Gail," Patterson replied.

Patterson earlier had been asked about messages she sent to Facebook friends about Don and Gail in December 2022, including "this family, I swear to f***ing god" and "I'm sick of this s**t, I want nothing to do with them".

Patterson said she regretted and was ashamed of the comments, but denied they were her true feelings or that those feelings persisted to July and August 2023.

"I suggest your private face is the one you've shown in your Facebook use," Dr Rogers said.

"Incorrect," Patterson responded.

"How you truly felt about Don and Gail was expressed in your Facebook messages," the prosecutor said.

"Incorrect," the accused said.

The prosecutor asked Patterson about two conversations she had with Simon, who had informed her his parents were "crook" in hospital following the lunch.

Patterson denied the conversations had ended after her estranged husband told her of their health state.

When Dr Rogers suggested she never asked Simon how his parents were after he informed her of their illness, Patterson replied: "Disagree".

Patterson confirmed in court her account to police where she said she loved Don and Gail.

The mushroom cook was asked about her relationship with Ian and Heather Wilkinson, which Ian had described to the jury as being "more like acquaintances".

Dr Rogers said the Wilkinsons were excited to about the lunch offer but Ian "wondered why the sudden invitation".

Patterson said there were a "few reasons", including that Ian had been her pastor for many years and she would speak to both after church.

"I really liked them. I wanted to have a stronger relationship with them," she said.

She told the jury she decided to invite them after Don and Gail complimented her garden, saying Heather would love to see it too, during a lunch at her house in June 2023.

"I wanted to say thank you to them for being good to me over the years," Patterson said, crying.

She said Heather used to sit with her at her daughter's playgroup.

Patterson also denied Dr Roger's suggestions she invited the two couples for lunch that day to ensure Simon would attend.

She was taken to screenshots from iNaturalist website URLs found on a Cooler Master PC seized from her home, allegedly accessed in May 2022, which Dr Rogers suggested led to a page about death cap mushrooms.

"I suggest you used Bing search to look up iNaturalist," Dr Rogers said.

"It does look like somebody did that, yes," Patterson responded.

"I suggest that person was you," the prosecutor said.

"I don't remember doing that. It's possible. The only thing that gives me cause is that I didn't use Internet Explorer or Bing but maybe I did this time. I'm not sure," she responded.

She was shown a screenshot of a specific post on iNaturalist featuring a sighting of death cap mushrooms in Moorabbin on May 18, 2022 and asked if she agreed she navigated to that specific post.

"I agree it's possible," Patterson responded.

The trial continues.