R v Patterson

1. The accused is charged with four counts of attempted murder (Charges 1-4) and three counts of murder (Charges 5-7).
2. The prosecution alleges that the accused deliberately poisoned her estranged husband Simon Patterson with meals containing an unknown poison or poisons prepared and provided by the accused on 16 November 2021 (Event 1), 25 May 2022 (Event 2) and 6 September 2022 (Event 3): (Charges 1-3).
3. The prosecution also alleges that the accused deliberately poisoned Simon Patterson's parents, Don Patterson and Gail Patterson, and Simon Patterson's uncle and aunt, Ian Wilkinson and Heather Wilkinson, when they attended a lunch at her home in Leongatha on 29 July 2023 to which Simon Patterson had also been invited but failed to attend (Event 4). It is not in dispute that, at that lunch, the accused served her lunch guests individually cooked Beef Wellingtons which contained death cap mushrooms. Soon after, the lunch guests fell gravely ill, were hospitalised and diagnosed with death cap mushroom poisoning. The accused, who also ate an individually cooked Beef Wellington, was also hospitalised, although her symptoms were comparatively mild: she was not diagnosed with death cap mushroom poisoning. Of the lunch guests, only Ian Wilkinson survived (Charge 4). Heather Wilkinson, Gail Patterson and Don Patterson died several days later in hospital (Charges 5-7).
4. This is a ruling regarding the admissibility of cell tower evidence which the prosecution relies on to prove that the accused probably sourced wild death cap mushrooms in Loch and/or Outtrim proximate to the fatal lunch.
5. The prosecution alleges that the accused was familiar with the iNaturalist website, which includes a world map indicating precise locations where death cap mushrooms have been sighted. After sightings of death cap mushrooms in Loch and Outtrim were posted on the iNaturalist site on 18 April 2023 and 21 May 2023 respectively, the prosecution alleges that the accused accessed that information and visited those towns for the purpose of obtaining death cap mushrooms to use in the Beef Wellingtons she served to her lunch guests on 29 July 2023.
6. In the course of pre-trial submissions, the prosecution narrowed the number of alleged visits by the accused to Loch and Outtrim to three: alleged visit 1 was to Loch on 28 April 2023;[1] alleged visit 2 was to Loch on 22 May 2023 between approximately 0919 to 1004;[2] and alleged visit 3 was to Outtrim on 22 May 2023 between approximately 1124 and 1149.[3]

1. The amended Summary of Prosecution Opening dated 24 February 2025 ('Summary of Prosecution Opening') states, relevantly (footnotes deleted):

234. [On 1 August 2023] [T]he accused said [to Sally Ann Atkinson of the Department of Health] that the lunch had consisted of beef wellington, mashed potato and beans served with gravy from a reheated packet. She stated that she had purchased the majority of the ingredients from Woolworths in Leongatha but that she had also purchased some dried mushrooms from an Asian shop in either Clayton, Mount Waverley or Oakleigh. The accused could not be sure of the location of the Asian shop. She also said she did not have the packaging for the mushrooms as they came in packaging that was not resealable, so she had thrown the packaging out and placed the mushrooms in a Tupperware container. She described the mushrooms as smelling funny, but they were ok when she used them so she had stored what was left for several months until she used them again.

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250. [On 3 August 2023,] Ms Atkinson asked the accused about the appearance of the mushrooms from the Asian grocer, and the accused described them as similar in colour to button mushrooms. Ms Atkinson pushed the accused to think about where she might have gone shopping, and the accused mentioned various roads in Oakleigh, Clayton and Glen Waverley, which she had not mentioned previously.

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255. The Department of Health's investigation concluded around 11 August 2023. They were unable to identify any store (in the suburbs identified by the accused to Ms Atkinson) that sold mushrooms as described by the accused. The Department received no other reports of people falling ill in the same way as the lunch guests. The cluster of illnesses was treated as an isolated incident and no products were recalled.

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271. In Victoria, the largest platform for recording observations and citizen science uploads of plants, animal and fungi is a publicly accessible website called 'iNaturalist'. On this website, members of the public can post sightings of a variety of plants and animals. Although an account is needed in order to post an observation, any internet user can look at the data and images uploaded to the website. Every observation is posted with a photograph and most have precise location information in the form of geospatial data. Internet users can readily search for images and locality information for a particular species, and view these via a map function.

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283. On 28 May 2022 at 7.20pm, ...the accused, using a computer which was later seized from her home, utilised the online search engine Bing to search for the term 'inaturalist', before navigating to the iNaturalist webpage. At 7.22pm, the accused navigated to a webpage on the iNaturalist site featuring a world map with geographic locations of death cap mushroom sightings. At 7.23pm, the accused navigated to a webpage on the iNaturalist website featuring a purported sighting of death cap mushrooms in Bricker Reserve, Moorabbin on 18 May 2022 (10 days prior) posted by user 'ivan-theaged'. A record of this search and website access was preserved in the computer's data as various artifacts...[4]

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298. On 18 April 2023, Christine McKenzie, a now-retired pharmacist and Senior Poisons Information Specialist at the Victorian Poisons Information Centre, observed death cap mushrooms under some oak trees during a walk with her husband and grandson in the regional township of Loch in eastern Victorian. She took a number of photographs and collected and disposed of every example that she could find. She did this as she knew how dangerous they were. Ms McKenzie had her daughter put up a post on the Loch community Facebook page warning people about the presence of the mushrooms, as she knew there would be more growing within a few days. She also posted four photographs of this sighting to the iNaturalist webpage under her username 'chrismck', which geo-tagged the discovery location. The images posted by Ms McKenzie have since been positively identified by mycologist Dr Tom May as death cap mushrooms.

299. In approximately March, April and May 2023, the accused started posting messages in the Keli Lane group chat about dehydrating mushrooms. She shared that she had purchased a food dehydrator and posted a few messages and photos about it in the chat, including a photograph of the dehydrator sitting on her kitchen bench. The accused explained that she had been dehydrating mushrooms, blitzing them into powder and hiding powdered mushrooms in everything. This included putting powdered mushrooms into chocolate brownies without her children knowing. She also shared with the group that the dehydrator reduces mushroom mass by 90 per cent.

300. The accused had in fact purchased a Sunbeam Food Lab Electronic Dehydrator, model DT6000, from Hartley Wells Betta Home Living in Leongatha at 12.17pm on 28 April 2023. In the morning prior to this purchase, at around 9.00am, the accused's mobile service data suggests that she travelled to and remained in the Loch area before returning to Korumburra. (underlining added)

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309. On 21 May 2023 at 2.50pm, Dr May, using his iNaturalist profile 'Funkey Tom' submitted an observation of death cap mushrooms along with a photograph and location of Neilsen Street, Outtrim, to the iNaturalist website. The location that he posted was within roughly 20 metres of the death cap mushroom sighting made by Dr May.

310. On 22 May 2023, the accused's mobile service data suggests that she travelled to and remained in the Loch area at around 10.00am before returning to Leongatha. Later that same day, the accused's mobile service data suggests that (having travelled to Loch between 9 and 10am) she travelled from Leongatha to the Outtrim area at around 11.00am, before returning to Leongatha. (underlining added)

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379. The prosecution alleges that the accused had a tendency to use a computer or other electronic device to access online content relating to amanita phalloides (death cap mushrooms), locations of amanita phalloides and/or locations of other poisonous flora. The prosecution relies upon the evidence of that tendency, together with other evidence in the case, to prove that the accused accessed online content via the iNaturalist website regarding sightings of death cap mushrooms in Loch, Victoria on 18 April 2023 and in Outtrim, Victoria on 21 May 2023.

1. Dr Matthew Sorrell is the prosecution's expert in relation to the cell tower evidence. There is no dispute regarding his expertise.
2. He has written four reports and given evidence at two s 198B hearings, one before Freeman JR on 11 December 2024 and one before me on 10 January 2025. His first report dated 11 March 2024 concerns possible visits by the accused to Outtrim. His second report dated 22 April 2024 mainly concerned trips coinciding with Events 1-3 and so is not relevant to this ruling. His third report dated 7 November 2024 concerned possible visits by the accused to Loch.
3. In relation to accused's mobile 0468331783, Dr Sorrell analysed the call charge records for the period 2019 to 2023 and event based monitoring data for specific dates during that four-year period.
4. According to Dr Sorrell, event based monitoring provides more 'granular' data than call charge records but are much more expensive than call charge records. The specific dates for the event based monitoring were mainly selected having regard to the results obtained from Dr Sorrell's initial analysis of the call charge records. An exception was made for 22 May 2023 when it is alleged by the prosecution that the accused visited both Loch, then Outtrim before midday. Analysis of the call charge records suggested that the accused had just passed through Outtrim on that day, rather than visited Outtrim. Analysis of the event based monitoring indicated otherwise.[5]
5. The thrust of Dr Sorrell's opinion evidence was that, based on both the call charge records and the event based monitoring, it was possible that the accused had visited Loch and Outtrim. More particularly, it was possible that she visited Loch on 28 April 2023 and 22 May 2023 and Outtrim on 22 May 2023. For the purposes of his analysis he defined Loch as contained within the boundaries of the town of Loch[6] and Outtrim as the area covered by the Outtrim postcode according to Google Maps (which is an area larger than the small township of Outtrim).[7]

1. Section references below are to the Evidence Act 2008 (Vic) unless otherwise indicated.

1. The accused submitted that the cell tower evidence in relation to alleged visit 1-3 was irrelevant (s 55, 56). Alternatively, the accused submitted that the probative value of the evidence was outweighed by the danger of unfair prejudice (s 137).
2. The accused highlighted the fact that on his own admission Dr Sorrell could only speak of possible visits by the accused to the Loch and Outtrim areas. Further, the area Dr Sorrell used as his reference for Outtrim - the area covered by the Outtrim postcode - was not confined to the township of Outtrim in which the death cap mushrooms were sighted by Dr May (posted on iNaturalist on 21.5.23). Dr Sorrell freely acknowledged other possible explanations for the data contained in the call charge records and the event based monitoring. Given the cell coverage of the relevant cell towers, Dr Sorrell was not in a position to exclude the possibility that the accused's mobile may have been outside the area that he used to define Loch and Outtrim on the occasions that he posited possible visits by the accused to those areas. The accused was living in Leongatha at the relevant times and would regularly travel on the South East Gippsland Highway (which connects Leongatha and Loch) and the Bass Highway (which connects Leongatha and Inverloch).
3. The accused submitted that there was risk that the jury would overvalue the evidence, a risk that could not be cured by directions.[8]

1. The prosecution submitted that when Dr Sorrell's evidence is assessed in the context of other evidence, and not in isolation, it is clearly relevant and its limitations will be readily grasped by jurors.[9]

1. The relevance and probative value of the cell tower evidence has to be assessed in the context of other evidence. That contextual evidence includes the following:
   • A jury could find that on 28 May 2022, the accused searched the iNaturalist website, navigating to the map regarding the sighting of death cap mushrooms and navigating to a particular sighting in Melbourne;
   • Sightings of death cap mushrooms in Loch and Outtrim were posted on iNaturalist on 18 April 2023 and 21 May 2023;
   • The accused purchased a food dehydrator on 28 April 2023, being the same day as the first possible visit to Loch;
   • The accused served a meal to her lunch guests on 29 July 2023 that contained death cap mushrooms;
   • In her first recorded police interview the accused told investigators that she sourced some dried mushrooms for the Beef Wellingtons from an Asian grocery. Her account to Health Department investigators as to the location of the Asian grocery changed. Initially she said the Asian grocery was in Clayton, Mount Waverley or Oakleigh (Summary of Prosecution Opening at [234]). Subsequently, she said the grocery could have been in Glen Waverley (Summary of Prosecution Opening at [250). Extensive inquiries by Health Department investigators of Asian groceries in the areas nominated by the accused did not discover any packaged dried mushrooms matching the description given by the accused;
   • There were no reports of death cap mushrooms poisonings contemporaneous to the fatal lunch;
   • The accused admits that she lied to investigators that she had never owned or used a dehydrator or foraged for wild mushrooms.
2. The impugned evidence does not prove that the accused visited Loch and Outtrim on the dates alleged: it rises no higher than the accused possibly visited those towns on those dates. But it is evidence of opportunity for the accused to have deliberately sourced death cap mushrooms for the fatal lunch at a time proximate to the lunch. As such it increases the probabilities of the accused having deliberately poisoned her lunch guests. A jury could reasonably reject the accused's claim that she unwittingly sourced death cap mushrooms from an Asian grocery, given the extensive investigations by the Health Department and the non-reporting of other death cap mushrooms deaths or illnesses at the relevant time. The limitations of Dr Sorrell's evidence are clearly articulated and easily understood. As such, it is unlikely that the jury will overvalue the evidence. Whilst the evidence is of modest probative value, I am not persuaded that its probative value is outweighed by the danger of unfair prejudice to the accused.

[1] Amended Summary of Prosecution Opening dated 24 February 2025 (SPO) [300].

[4] At [284] of the SPO, the following information appears:

Simultaneously, at 7.23pm, the accused navigated to the website of the Korumburra Middle Pub via the Google search engine. She used the website to order a 'family pack' of food, to be delivered to the accused's address of 46 Shellcot Road Korumburra. The accused's phone number ending 783 and name were entered into the website using Chrome Autofill. The accused's purchase was confirmed by the Korumburra Middle Hotel, who provided a receipt in the name of Erin Patterson for the purchase of meals and a bottle of soft drink, utilising the hotel's online ordering provider, YourOrder.

This information is relied on by the prosecution as proof that the accused was the one who was using the computer to also access the iNaturalist website at the time.

[5] See table for Outtrim on 22 May 2023 annexed to MJS's statement dated 26 February 2025.

[6] Consolidated Transcript for s 198 Hearings conducted before Freeman JR in 2024 (CTA) 1045.

[8] Defence Written Admissibility Submissions 1 (DWAS), [61-86]; Defence Oral Submissions (DOS), Consolidated Pre-Trial Transcript (CTB), 1006-1011, 1305-1313, 1325-1330.

[9] Prosecution Written Admissibility Submissions (PWAS) [32-34]; Prosecution Oral Submissions (POS), CTB 1313-1325.