Erin Patterson trial: Monash environmental health officer searched grocers for mushrooms

As Erin Patterson stands trial, mushroom packaging could hold key clues in the poisoning case. Photo / Brooke Grebert-Craig

An environmental health officer spent two days searching through Asian grocery stores in Melbourne after Erin Patterson told health authorities she used dried mushrooms, her triple-murder trial has heard.

Monash City Council officer Troy Schonknecht was called to give evidence about an investigation he undertook at the request of the Department of Health after the death cap mushroom poisoning event.

Patterson has pleaded not guilty to three counts of murder and one count of attempted murder stemming from a deadly beef Wellington lunch she hosted on July 29, 2023, with members of her husband’s family.

Earlier in the trial, the jury was told Patterson told public health authorities she used fresh mushrooms from Woolworths and dried sliced mushrooms purchased from an Asian grocer in Melbourne’s eastern suburbs in the lunch.

Schonknecht told the jury he spent two days, August 2 and 3, investigating more than a dozen grocers across the suburbs of Oakleigh, Clayton and Mount Waverley.

Initially, he said, he was told the purchase was likely in April 2022 and came in a clear, unbranded bag.

Later, he said, health authorities informed him the purchaser had confirmed they were dried, sliced, appeared to be repackaged, looked like shiitake or porcini mushrooms and were about 100g.

As he was taken through a report of his findings, which included photos of packaged mushrooms and the stores, Schonknecht said the majority came in commercial packaging.

In only one store, he said, Golden Grocery in Oakleigh, he found repackaged mushrooms, but the store had the bulk 3kg bag and said it repackaged them because customers wanted a smaller size.

Schonknecht told the jury he sent a photo to the Department of Health, which showed the image to the “purchaser”.

He said he was told the packaging “was correct” but the store didn’t look the same, and the mushrooms purchased were “half the size”.

Schonknecht told the jury that each store confirmed it had not recently changed suppliers or sold mushrooms acquired from a non-commercial source locally.

Patterson cried in hospital, jury told

Called to give evidence, Leongatha hospital nurse Mairim Cespon told the jury she assisted Patterson after she checked into hospital about 9.48am on July 31.

The court was told Patterson initially presented at 8.05am but discharged herself against medical advice five minutes later.

Cespon told the court Patterson became “emotional and started crying” when she was told by Dr Chris Webster her two children would need to be assessed.

The court was told Patterson had said her children had eaten the lunch leftovers on July 30 with the pastry and mushrooms scraped off.

“She was asking if it is really necessary for them to be assessed because they don’t have any symptoms,” Cespon said.

“Doesn’t want them to be stressed or panicked … for the kids to be pulled out of school.”

Cespon said Patterson rated her pain at a 7/10 and complained about nausea, a “cramp-like pain” and diarrhoea.

The jury was shown a chart Cespon completed of Patterson’s bowel movements while at Leongatha Hospital.

Cespon said she sighted liquid bowel movements using a “witches hat” device at 10am, 10.04am, 10.06am, 10.15am and 11.50am.

A sample taken, she confirmed, was clear, mostly liquid with some brown sediment.

Don Patterson and Gail Patterson, Erin Patterson's parents-in-law, died after a suspected mushroom poisoning.

Judge’s warning to mushroom trial jurors

One question and answer between Victoria Police senior digital forensic officer Shamen Fox-Henry and a prosecutor on Wednesday prompted a firm warning from the trial judge to the jury.

Fox-Henry told the court he was tasked with generating a report about the contents of a Cooler Master computer seized from Patterson’s home after the lunch.

He took the jury through a series of records that captured online activity on the device in the evening of May 28, 2022.

One of the records captured a visit to a specific page on the citizen science website iNaturalist at 7.23pm.

“Deathcap from Melbourne, Vic, Australia on May 18 2022 … Bricker Reserve, Moorabbin – iNaturalist,” the headline for the page read.

Fox-Henry was quizzed by prosecutor Jane Warren about the specific URL listed and, if it remained available online, if one copied the URL into a browser the web page would load.

He confirmed that it would.

The exchange prompted a warning from Justice Christopher Beale that the jury should not test this out themselves.

“Don’t be tempted overnight to … put any of these URL addresses into Google and conduct your own searches, okay? You’re not investigators,” he said.

The warning echoes Justice Beale’s direction to jurors at the start of the trial that they must decide the case only on the evidence before the court.

“When you retire to consider your verdict, you will have heard or received in court all the information that you need to make your decision,” he said.

“You must not conduct your own research into the case or discuss the case with others who are not on the jury.”

On Wednesday, Fox-Henry was the sole witness called to give evidence and was to return to the stand on Thursday.

When the trial resumed about 11.40am, Justice Beale advised jurors that the plan was to interpose two witnesses before Fox-Henry continued.

Patterson is accused of murdering husband Simon Patterson’s parents, Don and Gail Patterson, and his aunt Heather Wilkinson.

Wilkinson’s husband, Korumburra Baptist Church pastor Ian Wilkinson, fell gravely ill but recovered.

Prosecutors allege Patterson deliberately spiked the lunch with “murderous intent”, while her defence argues the case is a “tragic accident”.

The trial continues.