Mushroom expert gives evidence in Erin Patterson trial
Emily Woods |
Poisonous mushroom identification is fraught with challenges and toxicity is often determined after they are ingested, an expert has told Erin Patterson’s triple-murder trial.
Patterson has pleaded not guilty to three counts of murder and one of attempted murder over a July 2023 lunch at her home in Victoria’s southeast.
Three of her lunch guests – her former in-laws Don and Gail Patterson, both 70, and Gail’s sister Heather Wilkinson, 66 – died after eating a death cap mushroom-laced beef Wellington she cooked for them.
Patterson claims she did not intentionally kill any of her lunch guests and it was a “terrible” accident, her lawyers have previously told the jury.
Mycologist Tom May gave evidence on Tuesday, explaining in detail how mushrooms grow and how death cap mushrooms are identified.
Under cross-examination by Patterson’s defence barrister Sophie Stafford, Dr May was shown 10 photographs of mushrooms and asked whether they appeared consistent with death caps.
Dr May agreed there were “many challenges” in trying to identify a mushroom from a single image.
“We simply don’t know whether those mushrooms are toxic until someone consumes it, is that right?” Ms Stafford asked.
“That is generally a way that we determine the mushroom is toxic, after an ingestion and connecting symptoms,” Dr May replied.
“It is possible to analyse mushrooms for known toxins, so that would be another way.
“In general, the way that we have determined that native Australian fungi are toxic is through symptoms after ingestion.”
She asked whether Dr May agreed that poisonous mushroom identification was “fraught with challenges”.
“It is challenging,” Dr May replied.
He said “mistaken identity” could occur when someone believed they were collecting a non-toxic mushroom but it ended up being poisonous.
He confirmed it was possible to have non-toxic and toxic mushrooms growing alongside each other.
Earlier, Dr May was questioned by prosecutor Nanette Rogers on a post he listed on the iNaturalist website about death cap mushrooms being found in Gippsland months before the fatal dinner.
He posted four photos and an exact location for the mushrooms, on Neilson Street in Outtrim, under his username “funkeytom” on May 21, 2023, the jury was told.
“I would say, taking together the combination of the features, that I would be with a high degree of confidence identifying those images as amanita phalloides (death cap mushrooms),” Dr May said.
Dr Rogers told the jury, during her openings on April 30, the prosecution will allege Patterson’s phone data “suggests” she travelled from her Leongatha home to Outtrim the day after Dr May’s post.
The fungi expert said there were two other sightings of death cap mushrooms in the Gippsland region: one in Loch on April 18, 2023, and one in Morwell recorded in the past 20 years.
Doctors who treated Patterson at Monash Hospital spoke to the jury about how she did not appear unwell and was discharged.
Patterson had taken herself to Leongatha Hospital on July 31, saying she was suffering from diarrhoea and abdominal pain, and she was then taken by ambulance to the Melbourne hospital.
Monash emergency doctor Varuna Ruggoo, who assessed Patterson on August 1, found she was “clinically well” after performing several tests.
She said Patterson had been cleared of potentially suffering from death cap mushroom poisoning by another doctor, Laura Muldoon.
Dr Ruggoo deemed Patterson fit to be discharged at 1pm that day.
Gail Patterson and Heather Wilkinson died at the Austin Hospital on August 4, and Don Patterson died the following day.
The trial before Justice Christopher Beale continues on Wednesday.
AAP
