Erin Patterson may have visited locations of death cap mushroom sightings, murder trial hears

An analysis of Erin Patterson’s mobile phone records revealed she may have visited two locations soon after death cap mushroom sightings were reported, a court has heard.

Patterson, 50, has pleaded not guilty to three charges of murder and one charge of attempted murder relating to the lunch she served at her house in Leongatha, Victoria, about 135km south-east of Melbourne.

She is accused of murdering her estranged husband Simon’s parents, Don and Gail Patterson, and his aunt Heather Wilkinson. She is also accused of attempting to murder Ian Wilkinson, Simon’s uncle and Heather’s husband.

The Victorian supreme court sitting in Morwell has previously heard the guests died after being poisoned with death cap mushrooms. The prosecution alleges Patterson deliberately poisoned her lunch guests with “murderous intent”, but her lawyers say the poisoning was accidental.

In the prosecution opening to the case, Nanette Rogers SC said Patterson’s phone records suggested she visited Loch and Outtrim in the months before the lunch.

The court has previously heard that two posts were made on “citizen science” website iNaturalist about death cap mushroom sightings at those locations in 2023.

On Monday, Dr Matthew Sorell, a digital forensics science expert who analysed Patterson’s mobile phone records for police, gave evidence in her trial.

His analysis was based on a timeline of when Patterson’s phone connected with base stations in the region, and how long they remained connected to those base stations, or base stations within the same area, indicating that the phone had remained relatively stationary for a specified period of time.

He said that the records provided to him by police, which covered from 2019 to August 2023, show it was possible that Patterson visited and stayed in Outtrim between 11.24am and 11.49am on 22 May 2023.

The fungi expert Dr Thomas May told the court last week that he uploaded a post on iNaturalist on 21 May 2023 identifying death cap mushrooms in Outtrim, including photos and specific coordinates which outlined it was found in Neilson Street.

Sorell agreed that Neilson Street was within the area specified in his analysis.

He also agreed that based on his analysis there was “potential” for the phone to have been stationary, consistent with a visit to Loch, for about 45 minutes on the morning of 28 April 2023.

He said a similar visit was possible on the morning of 22 May 2023, though noted there was an absence of records for part of this morning.

The court heard earlier on Monday from Christine McKenzie, a retired pharmacist and former poisons information specialist at the Victorian Poisons Information Centre, who said she discovered death cap mushrooms in Loch on 18 April 2023.

Witness Christine McKenzie departs the court in Morwell. Photograph: James Ross/AAP

She had been walking with her grandson and dog around the local oval when she spotted them under oak trees, and pulled out two mushrooms carefully to photograph for iNaturalist, before removing as many as she could see using a dog poo bag.

She did so because she knew the area was popular with dog walkers and also a local kindergarten regularly visited.

“You were also concerned because didn’t want anyone to mistake the species for an edible species of mushroom and accidentally forage them,” Christine Stafford, a lawyer for Patterson asked.

“That’s right,” McKenzie responded.

McKenzie posted on iNaturalist, using her username ChrisMcK, about 1pm that afternoon.

The trial before Justice Christopher Beale continues.