An Australian mum-of-two who murdered three people by serving beef wellington laced with poisonous mushrooms will never be released from prison.

Erin Patterson was refused by the Court of Appeal in Melbourne to have her convictions overturned after her lawyers argued she had suffered a miscarriage of justice.

She was sentenced to life in prison with a minimum of 33 years in September 2025 over the murders of her parents-in-law, Don and Gail Patterson, and her aunt-in-law Heather Wilkinson.

They were served a beef wellington laced with poisonous death cap mushrooms at Patterson’s home in Leongatha, Victoria, for a ‘reconciliation lunch’ and later died in hospital.

Mrs Wilkinson’s husband Ian was also served the meal but survived.

Patterson’s ex-husband, Simon, was also invited but decided last-minute not to attend.

Justice Stephen McLeish said: ‘This offending was extraordinarily cold and calculated and stands to be denounced in the strongest terms.

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

Patterson’s lawyers argued that prosecutor Nanette Rogers was ‘unfair and oppressive’ in cross-examining her for five days.

They also said the judge, Christopher Bale, had caused ‘unfair prejudice’ by allowing evidence from Patterson’s Facebook friends.

The court dismissed her attempt, and she must now appeal to the court’s High Court.

After becoming unwell, Heather spoke to Simon to tell him Patterson had eaten from a ‘noticeably different’ plate.

‘Does Erin have a shortage of crockery? I have been wondering about it since yesterday,’ Heather said, according to the prosecutor.

Their symptoms were described as being consistent with poisoning by death cap mushrooms, which is a dull green fungus known scientifically as Amanita phalloides and can cause serious organ failure within 24 to 48 hours.

Prosecutors suggested Patterson had two faces – the woman who publicly appeared to have a good relationship with her parents-in-law, while her private feelings about them were kept hidden.

Patterson previously said she became unwell after eating the meal, and while in the hospital, her ex-husband, Simon Patterson, accused her of poisoning his parents.

The trial also heard that Patterson had told her friends she was hiding ‘powdered mushrooms in everything’.

A woman who met Erin through a true crime forum on Facebook has said the accused killer was a ‘bit of a super sleuth.’

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