Sweet-smelling fungi at centre of Australian triple-murder trial are deadliest mushrooms in world

Erin Patterson faces trial over a mushroom-laced meal that killed three relatives.

Jury members have retired to decide the fate of an Australian woman accused of murdering three members of her husband’s family with a toxic mushroom-laced beef Wellington lunch.

Jurors began deliberating their verdict on 50-year-old home cook Erin Patterson after a nine-week trial, with each twist consumed by a global audience.

The trial revolves around an innocuous-looking mushroom with a “slightly sweet” smell and a sinister name.

Patterson is accused of killing her husband’s parents and aunt in 2023 by lacing their beef Wellington lunch with highly toxic death cap mushrooms.

She has strenuously denied the charges, saying the hearty meal was contaminated by accident.

“You must decide whether any of her statements were untrue,” Judge Christopher Beale said in his final instructions to the jury.

“You should consider all of the evidence in the case and draw reasonable conclusions based only on the evidence you accept.

“Do not guess.”

Jurors must reach a unanimous verdict - guilty or not guilty - for each of the four charges Patterson faces, Beale said.

The 14-person jury was reduced to 12 by ballot before they started debating a verdict at the court in Morwell, southeast of Melbourne.

They will be sequestered at night during the deliberations.

Throughout a headline-grabbing trial, experts have dissected the brown-and-white fungi in forensic detail.

Death caps – or Amanita phalloides – are responsible for around 90% of all fungus-related fatalities, making them the deadliest mushrooms in the world.

The brown-and-white sporing bodies are easily mistaken for other edible varieties and reportedly possess a pleasant taste when used in cooking.

But they are saturated with deadly chemicals known as amatoxins, toxicologist Dimitri Gerostamoulos told Patterson’s trial.

“They can lead to someone experiencing symptoms of diarrhoea, vomiting, feeling really unwell,” Gerostamoulos told the jury.

“And they progressively get worse if the toxins are not removed.

“They progress to tissue necrosis, organ failure, and can obviously lead to death if not treated appropriately.”

Three of Patterson’s guests died of organ failure a week after unknowingly eating death cap mushrooms baked into individual portions of beef Wellington.

“It was very apparent that this was not survivable,” intensive care specialist Stephen Warrillow told the jury.

A fourth guest fell gravely ill but survived after weeks in hospital.

Death cap mushrooms are native to Europe but have spread to the United States, Australia and New Zealand, fungi expert Tom May said during Patterson’s trial.

He said the mushrooms had a “slightly sweet” odour when fresh.

“In Australia, it is an exotic species and it was accidentally introduced,” May said in his testimony.

They sprout during warm and wet autumn weather and are typically found growing in the shade of oak trees.

“From time to time, every year usually under suitable conditions, it produces a sporing body, which is the mushroom that we see,” May said.

“They’re quite fleshy and they decay quite readily, so they would not last longer than a couple of weeks when they’re sitting in the field.”

- Agence France-Presse