Mushroom killer Erin Patterson to die in prison after appeal spectacularly backfires

Death cap mushroom murderer Erin Patterson will die in prison after an appeal court found her offending so cold, calculated and shocking that she should never have the chance at parole.

Court of Appeal justices Stephen McLeish, Leslie Taylor and Peter Kidd handed down their decision on Friday, throwing out Patterson’s appeal against her conviction and accepting an argument from prosecutors that her sentence had been manifestly inadequate.

Patterson, 51, has been serving life in prison with a non-parole period of 33 years, after being found guilty by a jury last year of the poisoning murders of her in-laws Don and Gail Patterson, Gail’s sister, Heather Wilkinson, and attempting to murder Heather’s husband, Ian Wilkinson.

Patterson has become only the second Australian woman to receive such a life sentence without parole.

The first was NSW abattoir worker Katherine Knight, who stabbed her de facto husband, John Price, 37 times, skinning him and cooking his body parts as a meal designed for his children in February 2000.

Earlier, sentencing Justice Christopher Beale, who has now retired, resisted calls at the time to jail Patterson for life with no prospect of parole, finding her case was so infamous she was likely to find custody more onerous than others.

However, the Court of Appeal found Patterson’s persistent murderous intent had protracted the suffering of her victims.

They said Patterson had for nearly three weeks, coldly planned and executed the murders, including extending the invitation to lunch and hiding the truth for nearly a week as her victims lay dying.

“This offending was extraordinarily cold and calculated, and stands to be denounced in the strongest terms,” McLeish said.

“In all the circumstances, after anxious consideration, we have concluded that the case involved such shocking criminality that it is inappropriate to fix a non-parole period.”

Patterson was not in court to hear the judgment. Instead, she appeared via videolink from jail dressed in a prison-issued blue jumper and glasses.

In court was Erin’s former brother-in-law Nathan Patterson, the sole family member to attend Friday’s decision, with surviving lunch guest Ian Wilkinson notably absent. Erin’s ex-husband Simon Patterson was not in court.

Nathan Patterson sat with members of the homicide squad – including Nigel L’Estrange and Stephen Eppingstall – who appeared shocked at the judgment was handed down. Outside court, they were all smiles, as were the prosecution, who grinned as they walked down Williams Street and Lonsdale Street to their nearby offices.

Patterson’s appeal barrister, Richard Edney, had earlier argued there were a number of potential irregularities in his client’s case, including during the jury’s seven-day sequestration at a Gippsland hotel while they were deciding Patterson’s fate.

The court heard jurors stayed in the same Traralgon hotel as members of the prosecution and police involved in the case, which Edney claimed amounted to a catastrophic and fundamental failure to comply with the trial rules.

Edney said the “inexplicable failure” to separate the jury created a potential miscarriage of justice with the media seemingly knowing more about potential interactions between the jury and others at the Latrobe Valley hotel than the prosecution did.

It followed an 11-week trial in Morwell, in Victoria’s east in mid-2025, which heard from more than 50 witnesses.

PATTERSON APPEAL ARGUMENTS

Patterson’s defence team submitted seven reasons the mushroom murderer’s convictions should be overturned:

1. The jury was potentially contaminated by staying in the same hotel as prosecutors and police.
2. Patterson was grilled unfairly by prosecutors during eight days in the witness box.
3. The prosecution told the jury it did not have to prove a motive for the murders but then spent substantial time implying she was angry at the Patterson family over a child support dispute.
4. Large tranches of evidence were wrongly shown to the jury, including mobile phone tower links to two areas in rural Gippsland where deadly mushrooms grew.
5. Photos and videos found on Patterson’s devices that could have backed her claims of being a mushroom forager were not shown to the jury.
6. Evidence from Facebook “friends” was not relevant, or their probative value was outweighed by unfair prejudice.
7. Prosecutors used family text messages to imply Patterson arranged the lethal lunch after fighting with the family when no motive was put forward as part of the case.

Jury keepers reported no contact had occurred with anyone outside the jury pool, the court heard.

This, McLeish said was “significant” because it stood in the face of an argument otherwise based on conjecture.

Edney also argued that Patterson had been unfairly grilled by the prosecutor over eight days in the witness box, that 35 errors occurred in their closing address to the jury and that large amounts of evidence should not have been allowed into the trial.

Director of Public Prosecutions Brendan Kissane, KC, had dismissed the concerns as baseless and not warranting the granting of an appeal.

The trial was told Patterson fed her four guests beef Wellington laced with death cap mushrooms during lunch at the mother-of-two’s Leongatha home in July 2023.

Simon Patterson, the killer’s estranged husband, had also been invited to lunch but cancelled the evening before.

Heather Wilkinson and Gail Patterson died on August 4, 2023, from multiple organ failure, with a diagnosis of amanita mushroom poisoning. Don Patterson died the following night.

Local pastor Ian Wilkinson survived after spending several weeks in an induced coma.

Speaking on behalf of the court, McLeish read out the findings that Patterson’s appeal was unsuccessful.

The first ground that Patterson had argued was that the jury’s accommodation - being at the same location as prosecutors, police and media covering the case - contravened the principle that “justice must not only be done, but must be seen to be done”.

“Significantly, the judge’s tip staff, who was one of the jury keepers, assured the judge that there had been no interaction between the jury and the informant or prosecution solicitors, as against that assurance, there was only conjecture, guesswork, or surmise,” McLeish said.

He said the court had found no basis to believe the jury wouldn’t have reached its verdict according to law despite their accommodation.

On the second of Patterson’s appeal grounds, being whether the evidence presented to the jury derived from mobile phone data about her visits to two locations where death cap mushroom had been spotted was admissible, McLeish said:

“The court has decided that this evidence was admissible as part of the wider circumstantial case advanced by the prosecution, which included the purchase by the applicant of a food dehydrator on the same day as one of the possible visits,” he said.

“The second ground is therefore also unsuccessful.”

The final grounds for her appeal, including that a “substantial miscarriage of justice had resulted from the way the prosecution treated the issue of motive during the trial”, as well as “what was said to be the unfair cross-examination” of Patterson, were also dismissed.

Turning to the DPP’s appeal against Patterson’s sentence - that her non-parole period of 33-years was “manifestly inadequate” - the justices found that it was not reasonably open to fix a non-parole period, because it did not reflect the calculated criminality of the case on the facts identified by the sentencing judge.

“On those facts, [Patterson’s] intent to murder all four victims was sustained for nearly three weeks, from when she invited them to lunch through to preparing and serving the poisonous meal,” he said.

“Then throughout the protracted suffering and ultimate deaths that resulted, the applicant’s conduct was characterised by an elaborate series of deceptions, including the false cancer claims deployed to explain the absence of the children, the false denials of having foraged the mushrooms, the repeated false assertions as to the source of the mushrooms, and the destruction of evidence.”

Patterson’s actions were “carefully planned and deliberate,” he said. He labelled her actions against the family a “cruel breach of trust”.

“It is necessary that the sentence vindicates unequivocally the primary value that our society places on each individual human life,” McLeish said.

“As already noted, the applicant’s murderous intent dated back to the invitations to lunch, it persisted through the lunch when the poison was administered, and for nearly a week after that, during which time the applicant repeatedly tried to hide the truth about the source of the mushrooms, even as the victims continued to suffer.

“We have concluded that the case involved such shocking criminality that it is inappropriate to fix a non-parole period.”

Patterson now had 28 days to decide if she takes her fight to the High Court.

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