'Mushroom killer' found guilty of poisoning relatives appeals murder conviction claiming 'catastrophic' mistake

Erin Patterson, the Australian woman convicted of murdering three relatives with a deadly mushroom-laced lunch, is back in court as she fights to overturn the verdicts against her.

The 51-year-old was found guilty last year of murdering her estranged husband Simon Patterson’s parents, Don and Gail Patterson, as well as Gail’s sister, Heather Wilkinson, in 2023.

Heather’s husband, Ian Wilkinson, survived after eating the same beef Wellington meal at Patterson’s home in Leongatha, Victoria, but spent weeks in critical condition in hospital and later required a liver transplant.

Patterson had denied deliberately poisoning her guests throughout her nine-week trial, maintaining that the deaths were the result of a terrible accident involving death cap mushrooms that she had foraged.

She was eventually sentenced to life in prison with a minimum term of 33 years.

Erin Patterson is currently serving life with a 33-year minimum term after being convicted of three counts of murder (Pool/Pool/Getty Images)

Now, Patterson’s lawyers are arguing that a major problem with the jury’s arrangements during deliberations was so serious that her convictions should be quashed.

Her barrister Richard Edney told Victoria’s court of appeal that jurors had stayed at the same hotel as the police informant in charge of the case, as well as lawyers from the office of public prosecutions while they considered their verdicts.

Edney argued the failure to properly separate the jury amounted to a fundamental irregularity which denied Patterson a fair trial.

Reported by The Guardian, he told the court: “What we say has occurred here in the applicant’s trial was an inexplicable and perhaps still unexplained failure of a process.

“We would describe the sequestration and what occurred during it as catastrophic. There has been a fundamental failure here to comply with the dictum I’ve been referring to.”

Don and Gail Patterson were among three people killed after the lunch - the other being Gail's sister, Heather (Asanka Ratnayake/Stringer/Getty Images)

However, the prosecution has pushed back against that claim, stressing there is no evidence jurors actually spoke to members of the prosecution or police.

Brendan Kissane KC said: “There’s no evidence whatsoever that any member of the jury spoke, or had the opportunity to speak, with anyone other than their fellow jury members or jury keeper, let alone a member of the prosecution team.”

Justice Peter Kidd also questioned the argument, noting there was no evidence improper communication had taken place.

Patterson’s legal team has raised several other grounds of appeal too, including challenges over cell tower evidence and death cap mushroom sightings used during the trial.

Her defence also argues photos and videos relating to mushrooms found on an SD card at Patterson’s home should have been admitted as evidence that she had previously foraged for mushrooms.

The lunch Erin Patterson prepared for her former in-laws contained deadly death cap mushrooms (WILLIAM WEST/AFP via Getty Images)

Another ground claims her cross-examination, which lasted about six days, was ‘unfair and oppressive’, whilst her lawyers also allege prosecutor Nanette Rogers SC misstated evidence on 36 occasions during her closing address.

Patterson watched the appeal hearing by video link from Dame Phyllis Frost Centre and did not speak.

The hearing is continuing, with Victoria’s director of public prosecutions also appealing Patterson’s sentence on the grounds that it is ‘manifestly inadequate’.