The case of a mother from country Victoria accused of deliberately killing her in-laws with a poisoned lunch became one of Australia’s biggest mysteries.

On the day of her arrest, Victoria Police Detective Inspector Dean Thomas said he couldn’t “think of another investigation that has generated this level of media and public interest, not only here in Victoria but also nationally and internationally”.

The huge public interest in the fascinating case has meant the trial was covered extremely carefully in the media, with many things unable to be reported or said in order to ensure there was no prejudicing the jury.

There was fear of the jurors being influenced by the media, social media and all the general speculation and conversation around the case.

While only 12 jurors decided on the verdict, 15 were empanelled to sit through the long trial for this reason.

Today, Justice Beale ruled pre-trial evidence – including the previous alleged murder attempts of Simon Patterson by Erin – could be released to media after it was suppressed during the trial.

Erin was accused of trying to kill her husband – four times

She allegedly tried to poison him in the towns of Korumburra between November 16 and 17, 2021, in Howqua between May 25 and 27, 2022 and in Wilsons Prom on September 6, 2022.

On November 2, 2023, Victoria Police charged her with three counts of attempted murder over these alleged incidents – at the same time that they charged with three counts of murder and two counts of attempted murder over the fatal lunch at her home.

“The further three attempted murder charges relate to three separate incidents in Victoria between 2021-2022,” a police statement said at the time.

“It’s alleged a 48-year-old Korumburra man became ill following meals on these dates.”

He revealed his family were asked to say goodbye to him twice in hospital due to fears he would not survive the gut illness, which required three emergency operations.

We therefore weren’t allowed to talk about these charges as Justice Christopher Beale told the jury to “put them out of (their) minds”.

“Those charges have been discontinued by the Director of Public Prosecutions,” he told the jury.

“In other words those charges have been dropped and you must put them out of your mind,” he said.

Justice Beale urged the jury to “dispassionately weigh the evidence” in the case.

Erin admitted she lied in a letter to homicide detectives

“I am now wanting to clear up the record because I have become extremely stressed and overwhelmed by the deaths of my loved ones,” the letter read.

“I am hoping this statement might help in some way. I believe if people understood the background more, they would not be so quick to rush to judgement.

In the statement, Erin allegedly said advice she received immediately after the deaths was to give a “no comment” interview to police, which she said she now regretted.

“I now very much regret not answering some questions following this advice given the nightmare that this process has become,” she said.

Erin said she found the police interview “terrifying and anxiety-provoking”.

She admitted she lied to investigators when she told them she had dumped it at the tip “a long time ago”.

She said she was at the hospital with her children “discussing the food dehydrator” when her ex-husband, the son of the dead couple, asked: “Is that what you used to poison them?”

Worried that she might lose custody of the couple’s children, Erin said she then panicked and dumped the dehydrator at the tip.

Erin alluded to media speculation about the fact her estranged husband, Simon Patterson, reportedly spent a fortnight in hospital in May last year with a severe stomach illness unrelated to the current incident.

She said she “reluctantly” agreed to nurse Simon Patterson for three weeks after he was discharged from hospital, before telling him that she did not want to reconcile with him.

Victoria Police told 9News at the time that the statement was “not a police statement taken by investigators”.

Erin’s potential motives

Prosecutor Nanette Rogers SC told the jury her legal team did not need to prove a motive for the alleged crimes.

“Now, why would the accused do this? What is the motive?” Rogers said towards the end of her opening address 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.

“What you will have to focus on and focus your attention on is whether you are satisfied beyond reasonable doubt that the accused committed the charges on the indictment, not why she may have done so.”

However, the prosecution did allude to many potential motives during the trial, particularly Erin’s relationship fracturing with her estranged husband and his family.

The trial heard Erin and Simon had a dispute over child support payments, over which Gail and Don Patterson tried to step in and solve, in late 2022.

It seems the relationship between Erin and the family became worse when she received a belated invite to Gail’s 70th birthday lunch in October 2022.

The trial heard Simon texted Erin from October 2022 in which he asked Erin whether she would be attending his mother Gail’s 70th birthday lunch with their children the next day.

Erin replied she knew nothing about the celebrations, and that perhaps the belated invite was just an “afterthought”.

“I might pass … as I’d rather not go somewhere I’m not welcome,” Erin said.

After some back and forth, Erin said she felt “very hurt” about not being invited.

“And your response is to say, I’m being ridiculous,” she texted.

Simon responded: “You’re as far off the mark as you possibly could be on this, you already have the facts, however, of course, you’re free to choose to think whatever you want to despite them.”

Simon Patterson told the trial Erin sent “extremely aggressive” messages to his mother and father in the weeks leading up to the fatal lunch.