Judges hearing an appeal by a woman serving life for murdering three people and the attempted murder of a fourth were told she did not get a fair trial.

Aug. 19 (UPI) -- Judges hearing an appeal by an Australian woman serving life for poisoning three relatives and the attempted murder of a fourth person were told Wednesday she did not get a fair trial because the jury, prosecutors and a key witness were all booked into the same hotel.

Lawyers for Erin Patterson, who was convicted in July 2025 of serving four lunch guests with Beef Wellington laced with deadly "death cap" mushrooms and sentenced to a minimum of 33 years, said the hotel mix-up had a "catastrophic" impact on the soundness of the trial, calling for the convictions to be overturned.

The jury had been sent away to deliberate, sequestered on their own, but a shortage of accommodation in Melbourne at the time resulted in them being checked into the same hotel as the prosecution team, a key witness for the prosecution, the lead homicide detective for the case and reporters.

"We maintain that this was a very serious breach of sequestration," Barrister Richard Edney told the three appeal judge bench.

Justice Peter Kidd noted that the jury members were accompanied by jury keepers whose job was to protect the integrity of their deliberations and that there was no reason to believe they had been regularly separated from these officials.

Edney acknowledged under questioning there was no evidence of communication between jurors and the prosecution team or the witness, but insisted sharing a hotel was an interaction that may have had a "subconscious influence."

He said there was no way of checking either way, but said that had the original trial judge known he would have rejected the arrangement as "preposterous" and insisted it was an unacceptable bungle that "undermined the verdicts and requires the quashing of the convictions."

He said a retrial was the only answer in order for justice "not only to be done, but to be seen to be done."

Earlier, Patterson's lawyers also presented arguments that parts of the evidence in her trial were wrongly applied while others that were essential to their defense case were wrongly ruled inadmissible.

Patterson's appeal in the Victoria Court of Appeal is being heard alongside a parallel appeal by the director of public prosecutions against her "manifestly inadequate sentence" on grounds she should never become eligible for parole.

The life term she was handed at her sentencing in September 2025 allows her to apply for parole after she has served 33 years.

Patterson was found guilty of the July 2023 murders of Gail and Don Patterson, the 70-year-old parents of ex-husband, Simon Patterson, his 66-year-old aunt, Heather Wilkinson, and the attempted murder of Heather's husband, Ian Wilkinson.