Australia's Mushroom Murderer Loses Her Appeal, and Wins Herself a Harsher Sentence: Life Without Parole

Victoria's Court of Appeal on Friday dismissed Erin Patterson's challenge to her convictions for poisoning four relatives with a death cap mushroom lunch and, in the same judgment, granted the prosecution's appeal against her sentence, resentencing her to life in prison with no possibility of parole.

The Supreme Court of Victoria said in a notice that judgment on both appeals was handed down at 10 a.m. Friday in Melbourne, which was Thursday evening in Boston. One appeal was Patterson's, asking the court to review and overturn the jury's findings of guilt. The other was brought by the Director of Public Prosecutions against the sentence. The court livestreamed the decision and published the full judgment online.

The background, as set out by the court: after a jury trial that ran from April to July 2025, Patterson was found guilty of murdering her former parents-in-law and her former mother-in-law's sister, and of attempting to murder the sister's husband, who survived. Justice Christopher Beale sentenced her on Monday, Sept. 8, 2025, to life imprisonment with a non-parole period of 33 years. The victims, both of her former in-laws aged 70 and the third aged 66, ate beef Wellington laced with death cap mushrooms at her home in Leongatha, in regional Victoria, in July 2023, AAP and SBS reported. The surviving guest spent nearly two months in hospital, SBS reported.

Patterson, 52, watched by video link from the Dame Phyllis Frost Centre, Victoria's maximum-security prison for women, and did not visibly react, according to AAP. Justices Stephen McLeish, Lesley Taylor and Peter Kidd heard the appeals.

Her lawyers had argued that she suffered a substantial miscarriage of justice. Their main ground was that the jury was not properly sequestered during deliberations, because jurors were put up in the same hotel as the lead police investigator and two prosecutors. AAP reported the defense called that decision "catastrophic." They also argued that the Crown's five-day cross-examination of Patterson was "unfair and oppressive" and that prosecutors improperly shifted their case by suggesting a new motive in closing arguments, according to AAP and SBS.

The court rejected each ground. On the hotel, McLeish noted that the jury keeper had verified there was no communication between the parties. "As against that assurance, there was only conjecture, guesswork, or surmise," he said, according to SBS, finding "no objective basis for a fair-minded person to reasonably apprehend that the jury might not have discharged its function." The court found the grounds were not made out and that she did not suffer a miscarriage of justice, AAP reported.

Then the court turned to the prosecution's appeal, led by Victoria's Director of Public Prosecutions, Brendan Kissane KC. Prosecutors had argued that the killings involved calculated premeditation, made worse by Patterson's failure to tell medical staff about the death caps while doctors were still trying to save her guests, SBS reported. The court agreed that the 33-year minimum was inadequate.

"The applicant'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, and then throughout the protracted suffering and ultimate deaths that resulted," McLeish said. In the written judgment, the court called the offending "extraordinarily cold and calculated" and said it "stands to be denounced in the strongest terms." It added: "This is a case of such shocking criminality that it is inappropriate to fix a non-parole period." The judges said her conduct "was characterised by an elaborate series of deceptions" and "represented a cruel breach of trust to members of (her) extended family," AAP reported.

AAP reported that the sentence makes Patterson only the second woman in Australia sentenced to life without parole. The first was Katherine Knight of New South Wales, jailed in 2001.

Patterson has always maintained her innocence and said she did not know the mushrooms were poisonous, ABC News reported. Her remaining options are narrow. Christopher Corns, a former criminal barrister and legal researcher, told the ABC that Victorian law generally allows one appeal against conviction, with a second permitted since 2019 reforms only where "fresh and compelling" evidence emerges. He called that route "most unlikely" for Patterson. Her "only hope," he said, is the High Court of Australia, which applies "very strict criteria" to decide which cases it will hear. The ABC noted that Cardinal George Pell's convictions were quashed by the High Court in 2020 after the Victorian Court of Appeal had rejected his appeal.

The trial drew reporters from around the world to the regional town of Morwell. Over 10 weeks the jury heard from more than 50 prosecution witnesses, Patterson testified for eight days, and jurors deliberated for six days, AAP reported. The lead detective was in court Friday, as was a son of the murdered couple. The surviving guest was not, AAP reported.

Not yet known: whether Patterson will seek special leave to appeal to the High Court, and how long she has to file.