Who is Erin Patterson? The ‘Mushroom killer’ back in court

Melbourne: Australia's Erin Patterson, convicted of murdering three relatives with a meal containing lethal death cap mushrooms, is back in court as her lawyers seek to overturn her convictions in a case that drew international attention.

Patterson, 51, was found guilty last year of murdering her estranged husband's parents, Don and Gail Patterson, and Gail's sister, Heather Wilkinson. She was also convicted of attempting to murder Heather's husband, Ian Wilkinson, who survived after spending more than seven weeks in hospital.

Patterson was sentenced to life imprisonment, with a non-parole period of 33 years. Her lawyers are now challenging the conviction, while prosecutors have separately appealed against the sentence, arguing it was too lenient.

Who is Erin Patterson?

Patterson lived in Leongatha, a small farming town in Victoria, Australia. She had been separated from her husband, Simon Patterson, since around 2020.

On July 29, 2023, Patterson hosted a lunch at her home for Don and Gail Patterson, Heather Wilkinson and Ian Wilkinson. Simon had also been invited but did not attend.

Patterson served the guests individual beef Wellingtons. According to the case, the meal contained Amanita phalloides, commonly known as death cap mushrooms, which are highly poisonous.

Patterson has maintained that she did not deliberately poison her guests.

What happened after the lunch?

The four guests were taken to hospital the following day with suspected gastroenteritis. Patterson herself went to Leongatha Hospital after experiencing stomach pain and diarrhoea but repeatedly declined admission. Doctors became sufficiently concerned about her condition that they contacted police.

There were also concerns about Patterson's two children, who she said had eaten leftovers from the meal. The mushrooms and pastry had reportedly been removed from the leftovers, but doctors insisted the children be checked for possible symptoms.

Five days after the lunch, on August 4, Gail Patterson, 70, and Heather Wilkinson, 66, died in hospital. Don Patterson, 70, died the following day despite undergoing a liver transplant.

Ian Wilkinson, 69, became seriously ill but survived after more than seven weeks in hospital.

What is Patterson's appeal about?

Patterson's lawyers told the Victorian Court of Appeal on Wednesday that problems surrounding the jury and the admission of evidence meant she did not receive a fair trial.

Lawyer Richard Edney argued that some jurors stayed at the same hotel as a police witness and members of the prosecution team. He described this as a "fundamental failure" of the legal process "in perhaps one of the most high-profile criminal trials this state has ever had".

However, Edney acknowledged there was no evidence that jurors had communicated with the people concerned.

Another lawyer, Veronika Drago, challenged evidence concerning cell towers and online posts about sightings of death cap mushrooms, describing some of it as "innocuous" and unreliable.

Patterson's lawyers have also argued that other evidence, including mushroom images found on a memory card at her home, was wrongly excluded. They have accused prosecutors of conducting an "unfair and oppressive" cross-examination.

The Court of Appeal must first decide whether Patterson has sufficient grounds to challenge her conviction.

Why is the prosecution appealing?

While Patterson is seeking to overturn her conviction, prosecutors want her sentence increased.

They argue that the 33-year non-parole period is "manifestly inadequate". Prosecutors say the sentencing judge wrongly concluded that Patterson had a substantial chance of spending years in solitary confinement, and that this consideration "infected" the sentencing decision.

A 12-member jury convicted Patterson in July last year of murdering Don and Gail Patterson and Heather Wilkinson, and attempting to murder Ian Wilkinson.

The appeals are being heard over Wednesday and Thursday, with Patterson following proceedings from the maximum-security Dame Phyllis Frost Centre in Melbourne via video link.