Crown v Accused

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 declined at the last minute (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. Each of 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, though 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 tendency evidence relied on by the prosecution in relation to Event 4 (Charges 4-7).

1. The prosecution's Amended Tendency Notice dated 24 January 2025 ('Tendency Notice') states relevantly:

2. The Prosecution seeks to rely upon the tendency of the accused to:

a. Act in a particular way, namely:

(i) To use a computer or other electronic device to access online content (including via the iNaturalist website) relating to amanita phalloides (death cap mushrooms), locations of amanita phalloides (death cap mushrooms) and/or locations of other poisonous flora.

...

4. The issues in the case to which tendency reasoning applies are:

1. Whether the accused deliberately sourced death cap mushrooms which went into the lunch that was served to the lunch guests on 29 July 2023 and, therefore, whether she acted with murderous intent in respect of charges 4, 5, 6 & 7.

Specifically, the tendency reasoning applies to:

(i) Whether the accused accessed online content via the iNaturalist website featuring a (since verified) sighting of death cap mushrooms in Loch, Victoria, posted by Christine McKenzie, using her iNaturalist username 'chrismck', on 18 April 2023; and

(ii) Whether the accused accessed online content via the iNaturalist website featuring a (since verified) sighting of death cap mushrooms in Outtrim, Victoria posted by Dr Tom May, using his iNaturalist username 'Funkey Tom', on 21 May 2023.

1. In its Tendency Notice, the prosecution alleges that on multiple occasions the accused accessed or possibly accessed online information regarding death cap mushrooms (x7)[1] and other poisonous flora (x1).[2] The prosecution alleges that 4 of the 8 occasions occurred on the iNaturalist website.[3]
2. [REDACTED]

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

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, namely: Windows Timeline Activity artifacts, Parsed Search Queries artifacts, Edge/Internet Explorer 10-11 Daily/Weekly History artifacts, Edge/Internet Explorer Main History artifacts, Potential Browser Activity artifacts, Chrome Web History artifacts, a Chrome Shortcut artifact, Chrome Favicons artifacts, Chrome Web Visit artifacts, Edge Chromium Web History artifacts, Edge Chromium Web Visits artifacts, IE InPrivate/Recovery URL artifacts, Chrome Cookies artifacts, Edge Chromium Cookie artifacts and Chrome Cache Records artifacts.

...

302. [REDACTED]

303. [REDACTED]

1. All section references are to the Evidence Act 2008 (Vic) unless otherwise indicated.
2. Sections 97 and 101 state relevantly:

97 The tendency rule

(1) Evidence of the character, reputation or conduct of a person, or a tendency that a person has or had, is not admissible to prove that a person has or had a tendency (whether because of the person's character or otherwise) to act in a particular way, or to have a particular state of mind unless -

(a) the party seeking to adduce the evidence gave reasonable notice in writing to each other party of the party's intention to adduce the evidence; and

(b) the court thinks that the evidence will, either by itself or having regard to other evidence adduced or to be adduced by the party seeking to adduce the evidence, have significant probative value.

101 Further restrictions on tendency evidence and coincidence evidence adduced by prosecution

(1) This section only applies in a criminal proceeding and so applies in addition to sections 97 and 98.

(2) Tendency evidence about an accused ... that is adduced by the prosecution cannot be used against the accused unless the probative value of the evidence substantially outweighs any prejudicial effect it may have on the accused.

1. In assessing whether an alleged tendency has significant probative value, Hughes v R[4] requires one to determine whether the evidence strongly supports the alleged tendency and whether the tendency strongly supports the ultimate fact in issue (here, whether the accused deliberately poisoned her lunch guests with murderous intention). The plurality stated:

The assessment of whether evidence has significant probative value in relation to each count involves consideration of two interrelated but separate matters. The first matter is the extent to which the evidence supports the tendency. The second matter is the extent to which the tendency makes more likely the facts making up the charged offence. Where the question is not one of the identity of a known offender but is instead a question concerning whether the offence was committed, it is important to consider both matters. By seeing that there are two matters involved it is easier to appreciate the dangers in focusing on single labels such as "underlying unity", "pattern of conduct" or "modus operandi". In summary, there is likely to be a high degree of probative value where (i) the evidence, by itself or together with other evidence, strongly supports proof of a tendency, and (ii) the tendency strongly supports the proof of a fact that makes up the offence charged.[5]

1. The prosecution submitted that the accused accessed online information on death cap mushrooms, and online information on the iNaturalist website about death cap mushrooms and other poisonous flora, on multiple occasions, thus strongly evidencing the alleged tendency. The prosecution submitted that this alleged tendency significantly increased the probabilities that she accessed the information on iNaturalist about death cap mushroom sightings in Loch and Outtrim in late April and May 23 and that having regard to cell tower evidence which indicates possible visits to those towns by the accused on 28 April 2023 and 22 May 2023, she deliberately poisoned the Beef Wellingtons with death cap mushrooms most likely sourced from Loch and/or Outtrim. The prosecution submitted that consequently the tendency evidence has significant probative value (s 97). Further, the probative value of the evidence substantially outweighs any prejudicial effect it may have (s 101). The prosecution submitted that the evidence does not disclose other criminal misconduct and directions will cure any risk of the jury misusing or overvaluing the evidence.[6]

1. The accused submitted that the tendency evidence is irrelevant (ss 55, 56), does not establish the alleged tendency, does not have significant probative value (s 97), and its prejudicial effect substantially outweighs any probative value it might have (s 101). The accused submitted that the prosecution assumes the very facts that the tendency evidence is adduced to prove, namely, that the accused accessed the relevant posts on the iNaturalist website and deliberately sourced death cap mushrooms in Loch and/or Outtrim for the Beef Wellingtons she served to her lunch guests on 29 July 2023. The accused submitted that the jury may also be confused by the prosecution's reliance on both coincidence reasoning (in relation to Charges 1-7) and tendency reasoning (in relation to Charges 4-7) and directions may not dispel that confusion.[7]

1. The submissions of the parties have to some extent been superseded by my ruling in relation to the computer evidence about poisons[8] and my ruling in relation to the coincidence evidence relied on by the prosecution.[9] [REDACTED] and the coincidence evidence is inadmissible, necessitating separate trials on Charges 1-3 concerning Simon Patterson and Charges 4-7 concerning the lunch guests.
2. The fact that there is only admissible evidence of the accused accessing the iNaturalist website once (28 May 2022) [REDACTED] makes it difficult to maintain that the evidence strongly supports the alleged tendency. The fact that the one instance of the accused accessing the iNaturalist website occurs approximately a year prior to the postings on the iNaturalist website of the relevant sightings of death cap mushrooms in Loch and Outtrim also undermines the claim that the tendency evidence has significant probative value. Accordingly, I am not persuaded that the tendency evidence clears the first hurdle created by s 98.

[1] I have counted the searches referred to in the amended Summary of Prosecution Opening dated 24 February 2025 (SPO) [308] as two searches.

[4] Hughes v R [2017] HCA 20; (2017) 263 CLR 338.

[6] The prosecution's written tendency submissions dated 11 February 2025 (PWTS); the prosecution's Oral Submissions (POS), Consolidated Pre-Trial Transcript (CTB), 1330-1338, 1347-1350.

[7] The accused's written tendency submissions dated 3 February 2025 (DWTS), the accused's Oral Submissions (DOS), CTB 1338-1347.