MELBOURNE, Australia — An Australian appeals court on Friday ordered triple-murderer Erin Patterson to never be released from prison because of the “shocking criminality” involved in poisoning four of her estranged husband’s relatives with death cap mushrooms.

The three judges of the Victoria state Court of Appeal dismissed Patterson’s appeal of her convictions and upheld prosecutors’ challenge to the leniency of her 33-year nonparole sentence, meaning she will spend the rest of her life behind bars. Beforehand, she would have been 82 years old when she could be considered for release.

“This offending was extraordinarily cold and calculated and stands to be denounced in the strongest terms,” Justice Stephen McLeish said on behalf of all three judges.

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

Patterson is only the second woman in Australia to be imprisoned for life without possibility of parole. The first is meatworker Katherine Knight, who was sentenced in New South Wales state in 2001 for the murder a year earlier of her partner John Price, whom she’d stabbed at least 37 times.

Patterson’s convictions stemmed from a family meal she hosted at her rural home in Leongatha in July 2023.

She can apply to Australia’s High Court to overturn the verdicts on her sentence and her convictions. The High Court is her last appeal option.

Patterson insisted she added death cap mushrooms to the beef Wellington pastry dishes accidentally.

She was sentenced last year to three life sentences for murder and 25 years for attempted murder.

The deaths of Patterson’s parents-in-law Don and Gail Patterson, and Gail’s sister, Heather Wilkinson, within days of having lunch immediately attracted an extraordinary level of global media attention.

The case has also inspired podcasts, books and screen adaptations.

Emmy-nominated actor Melanie Lynskey announced this week she will star as Erin Patterson in a six-episode series for the subscription video-on-demand streaming service Paramount+.

Lynskey is also executive producer of the series that dramatizes the 97 days from the fatal lunch until Patterson’s arrest.

Heather’s husband Ian Wilkinson survived the lunch after spending weeks in hospital. Erin Patterson was convicted of his attempted murder.

Prosecutors argued at an appeal hearing in August that she should never become eligible for parole.

They argued the minimum period behind bars did not reflect the “calculated criminality” of the case.

McLeish said Patterson’s intent to murder all four was sustained for almost three weeks from when she invited them to lunch.

Her crimes involved an “elaborate series of deceptions” including falsely claiming a cancer diagnosis to explain the absences of her two children from the lunch, the judge said.

The only survivor, Ian Wilkinson, testified that Erin Patterson had told her guests she wanted their advice about what to tell the children about her diagnosis.

McLeish noted Erin Patterson had destroyed evidence, denied foraging for mushrooms and repeatedly made false claims about where the mushrooms had come from.

“The offending was carefully planned and deliberate. It represented a cruel breach of trust,” McLeish said.

Patterson opted not to attend court and watched the verdicts by video link from prison.

Because of her notoriety, Patterson is held in the high-security Gordon Unit of Melbourne’s Dame Phyllis Frost Centre women’s prison. The unit is for prisoners assessed as being at high risk from other inmates.

In sentencing her in September 2025, trial judge Christopher Bale said there was a “substantial chance” that Patterson could be held in “solitary confinement for years to come.”

Patterson’s estranged husband, Simon Patterson, was invited to the lunch but declined the day before.

After her conviction, pretrial evidence was released that detailed the husband’s suspicion that Erin Patterson had previously attempted to kill him.

Simon Patterson testified at a pretrial hearing that he had declined the lunch invitation out of fear.