Victoria's Court of Appeal on Friday rejected Erin Patterson's bid to overturn her triple-murder convictions and instead imposed a harsher sentence that will keep her in prison for the rest of her life.

The three-judge panel dismissed all grounds of Patterson's appeal against her 2025 convictions for murdering her estranged husband's parents, Don and Gail Patterson, and his aunt, Heather Wilkinson. The court also upheld the prosecution's appeal against her original sentence, setting aside the 33-year non-parole period as manifestly inadequate.

Justice Stephen McLeish, delivering the judgment, described the crimes as "extraordinarily cold and calculated" and said they involved "such shocking criminality that it is inappropriate to fix a non-parole period." The court found Patterson's intent to murder was sustained for nearly three weeks, from the invitations to lunch through the preparation and serving of the poisonous meal.

Patterson, 52, was convicted last year after an 11-week trial of serving death cap mushrooms in a beef Wellington lunch at her home in Leongatha, Victoria, in July 2023. She was also found guilty of attempting to murder Heather Wilkinson's husband, Ian Wilkinson, who survived after weeks in hospital. She has maintained the poisoning was accidental.

The ruling makes Patterson the first woman in Victoria and only the second in Australia to receive a life sentence without the possibility of parole. She showed no emotion during the video-link hearing from prison.

Patterson now has 28 days to seek leave to appeal to the High Court of Australia, her final avenue for challenging the verdicts or sentence. Prosecutors had argued the original non-parole period failed to reflect the calculated breach of trust and deliberate planning involved in targeting family members.

The case drew widespread attention in Australia for the method of poisoning and the betrayal within the family. The court's decision underscores the gravity of the offenses, with judges emphasizing the need for the strongest denunciation of such premeditated acts.