Court of Appeal rejects Erin Patterson's appeal and removes non-parole period

Victoria's Court of Appeal on Friday rejected Erin Patterson's appeal against her conviction for the murder of four family members using death-cap mushrooms and increased the severity of her sentence. The three justices – Stephen McLeish, Lesley Taylor and Peter Kidd – found the original non-parole period of 33 years "manifestly inadequate" given the "shocking criminality" of the case.

Patterson, 51, has been serving a life sentence without the possibility of parole after a 2025 jury found her guilty of killing her in-laws Don and Gail Patterson, Gail's sister Heather Wilkinson, and of attempting to kill Heather's husband Ian Wilkinson. She became the second Australian woman to receive a life sentence without parole.

"This offending was extraordinarily cold and calculated, and stands to be denounced in the strongest terms," Justice 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," he added.

The appeal team had argued procedural irregularities, including alleged jury contamination from sharing accommodation with prosecutors and police, and claimed certain evidence should have been excluded. The court rejected each of the seven grounds, stating there was no basis to doubt the jury's verdict and that the evidence presented was admissible.

Prosecutor Brendan Kissane, KC, maintained that the concerns raised were unfounded and that the original sentence did not reflect the premeditated nature of the crimes. The judges agreed, noting Patterson's planning spanned nearly three weeks, from the invitation to lunch through the administration of the poison and subsequent attempts to conceal the source of the mushrooms.

Patterson appeared via videolink from prison and was not present in person. She has 28 days to decide whether to seek a further appeal to the High Court.