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).

1. The amended Prosecution Coincidence Notice dated 24 January 2025 states:
   • 1. Pursuant to s98(1)(a) of the Evidence Act 2008 (Vic), the Prosecution gives notice that it intends to adduce evidence which will be relied upon to establish that the accused did a particular act and/or had a particular state of mind namely:
   • 1.1 Deliberately poisoned Simon Patterson on 16/11/21 (Event 1);
   • 1.2 Deliberately poisoned Simon Patterson on 25/5/22 (Event 2);
   • 1.3 Deliberately poisoned Simon Patterson on or about 6/9/22 (Event 3);
   • 1.4 Deliberately poisoned Gail Patterson on 29/7/23 (part of Event 4);
   • 1.5 Deliberately poisoned Donald Patterson on 29/7/23 (part of Event 4);
   • 1.6 Deliberately poisoned Heather Wilkinson on 29/7/23 (part of Event 4);
   • 1.7 Deliberately poisoned Ian Wilkinson 29/7/23 (part of Event 4); and
   • 1.8 Intended to deliberately poison Simon Patterson on 29/7/23 (part of Event 4)

on the basis that, having regard to the similarities in the events and/or circumstances in which they occurred, it is improbable that each of the alleged victims suffered severe gastrointestinal illnesses after having consumed food prepared for them by the accused coincidentally.

2. The facts in issue that the Prosecution seeks to prove by relying on the improbability of coincidence are:

• 2.1. The illnesses suffered by the victims in events 1 to 4 were caused by the victims consuming food prepared by the accused;

• 2.2. The food prepared by the accused for each event was poisoned; and

• 2.3. The accused deliberately poisoned the food for each event.

3. The Prosecution relies on the following points of similarity ("S") between the events and the circumstances in which they occurred:

• 3.1. S.1: the accused was related by marriage to each victim;
• 3.2. S.2: the accused initiated/instigated each activity with Simon Patterson, and the four lunch guests, and arranged to provide/serve food;
• 3.3. S.3: the accused prepared the food;
• 3.4. S.4: the accused allocated the food;
• 3.5. S.5: the accused ate a separate meal from Simon Patterson, and the four lunch guests;
• 3.6. S.6: the accused's two children, [Redacted], were not present at the time the food was served to Simon Patterson, and the four lunch guests;
• 3.7. S.7: after consumption of the food each of Simon Patterson and the four adult family relatives suffered from severe gastrointestinal illnesses; and
• 3.8. S.8: at a time before or shortly after each event, the accused used a computer or other electronic device to access online content relating to poisons.

1. All section references below are to the Evidence Act 2008 (Vic), unless otherwise indicated.
2. Sections 98 and 101 provide as follows, relevantly:

98 The coincidence rule

(1) Evidence that 2 or more events occurred is not admissible to prove that a person did a particular act or had a particular state of mind on the basis that, having regard to any similarities in the events or the circumstances in which they occurred, or any similarities in both the events and the circumstances in which they occurred, it is improbable that the events occurred coincidentally 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.

Note. One of the events referred to in subsection (1) may be an event the occurrence of which is a fact in issue in the proceeding.

(2) ...

101 Further restrictions on ... coincidence evidence adduced by prosecution

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

(2) ... coincidence 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. The amended Summary of Prosecution Opening dated 24 February 2025 includes the following (footnotes deleted):

Trip to Wilsons Promontory, November 2021

Charge 1 - Attempted Murder

28. In 2019, the accused suggested to Simon Patterson that they go to South Africa together, travelling as a couple without their children. Simon Patterson agreed. They were to leave in March or April 2020, however, the trip had to be cancelled due to the onset of the Covid-19 pandemic.

29. As an alternative, the accused suggested that she and Simon Patterson go on a hiking and camping trip to Wilsons Promontory. The trip was delayed due to the changing Covid-19 restrictions, but eventually was to take place in November 2021.

30. On Tuesday 16 November 2021, the accused came to Simon Patterson's house in Korumburra to pack for the trip to Wilsons Promontory the following day. She gave him a Tupperware container of penne pasta Bolognese which she said she had made for the children to eat. The two of them sorted out what they needed to (sic) and the accused left. Simon Patterson finished the packing by himself and then ate the pasta before going to bed.

31. Early the following morning, he started to feel unwell. He drove to the accused's house to pick her up for the trip. [Redacted] were at the house, along with Tanya Patterson who was there to care for the children while their parents were away.

32. Shortly after arriving at the house, Simon Patterson vomited multiple times in the toilet. He attributed his condition to 'stress' and thought he would be alright, so he and the accused got into his car and left for their trip. The accused drove due to Simon feeling unwell.

33. As they were driving, Simon Patterson suddenly felt an urge to vomit. He quickly wound down the window and vomited. They continued on their journey but had to stop at Meeniyan where Simon suffered vomiting and diarrhoea and spent the morning going in and out of the public toilets. The accused booked some accommodation through Airbnb near Wilsons Promontory and they stayed there that night, as well as the following night. Simon Patterson was sick the whole time they were there, with continual vomiting and some diarrhoea. The accused provided Simon Patterson with electrolyte fluids and water. Simon discussed going to hospital with the accused, who suggested there might be a long wait there.

34. Eventually, on Friday 19 November 2021, the accused took Simon to the Urgent Care Centre at Leongatha Hospital. He was diagnosed with severe dehydration due to gastroenteritis and was admitted to the hospital. Blood test results showed he was suffering from acute renal impairment (kidney injury) with elevated creatinine levels and modestly elevated lactate. Simon was treated with intravenous fluids and his renal function was monitored. It continued to deteriorate despite rehydration. He remained in hospital overnight. The following morning, 20 November 2021, he was feeling better and was discharged with instructions to return to hospital the following day for further testing of his renal function.

35. On 21 November 2021, Simon Patterson returned to Leongatha Hospital as advised. Following further testing, which revealed his creatinine levels were still rising, Simon was transferred to Monash Medical Centre. A faecal specimen test conducted on 24 November 2021 revealed markedly elevated calprotectin, consistent with significant bowel inflammation. He remained in hospital as his renal function recovered and was eventually discharged on 27 November 2021.

36. During Simon Patterson's time in hospital, medical staff undertook extensive testing. The cause of his acute renal failure was presumed to be acute tubular necrosis secondary to dehydration due to the preceding gastroenteritis. However, the testing did not identify a cause of the vomiting and diarrhoea itself. Faecal specimens were negative for faecal pathologies and did not reveal underlying bowel pathology. Ultimately, treating doctors were unable to determine the underlying cause of this illness.

37. Simon was subsequently referred to consult with nephrologist Dr Trung Quach in the community, given he had suffered an episode of severe acute renal failure. His kidney function was monitored by regular blood tests and by 15 December 2021 it had normalised.

38. Following this episode, Simon Patterson underwent a colonoscopy on 5 April 2022, which revealed benign polyps, but was otherwise normal.

Trip to Howqua, May 2022

Charge 2 - Attempted Murder

39. Sometime after the November 2021 trip, the accused suggested to Simon that they go camping again, as they had missed out on their planned trip to Wilsons Promontory. Simon agreed and they planned a trip to Howqua, again as a couple without their children.

40. About a week before the trip, Simon Patterson went to the accused's house one evening. The accused was making chicken korma curry and wanted Simon and the children to taste test various levels of spice in the curry. Simon tried the curries and selected his favourite.

41. On Tuesday 24 May 2022, Simon and the accused went camping near Howqua, staying at a public campground. The children remained at home. On the second night of this trip, 25 May 2022, the accused and Simon ate chicken korma curry with rice for dinner. The accused prepared the food for serving, which she had brought pre-prepared for the camping trip, while Simon was attending to the fire. Simon did not see how the meal was packaged or prepared.

42. Early the following morning, 26 May 2022, Simon Patterson started to feel sick. He opened the tent door and vomited outside. He continued to vomit and experience diarrhoea while the accused packed up the camp. The accused drove Simon to Mansfield Hospital, stopping along the way so that he could vomit.

43. At Mansfield Hospital, Simon was treated with intravenous fluids and anti-nausea medication. His vital signs were unremarkable. Ultimately, Simon was discharged later that day after he had stopped vomiting. The accused booked accommodation in Mansfield through Airbnb and provided him with electrolytes. His condition seemed to be improving.

44. The following morning the accused drove Simon Patterson home. That night, he stayed at his house by himself. He was still feeling unwell.

45. Early in the morning on 29 May 2022, Simon Patterson got up before sunrise and tried to go to the toilet. He was having trouble making it to the bathroom and called the accused for help at 5.20am. The accused came to Simon's house. He felt weak. The accused called an ambulance at 5.45am.

46. Simon Patterson was taken to Monash Casey Hospital by ambulance. His vital signs were significantly abnormal, with very low blood pressure. He was treated in the ambulance with intravenous fluids and adrenaline, but his blood pressure remained low for a further 90 minutes despite these treatments.

47. Simon Patterson was admitted to Casey Hospital in haemodynamic shock. Initial blood testing revealed severe lactic metabolic acidosis, hypothermia, multi-organ failure, marked elevation of ALT suggesting liver ischemia and a blood film consistent with severe sepsis. An abdominal CT scan demonstrated severe bowel pathology with portal venous gas in the left lobe of the liver, a small volume of gas in the mesenteric vessels to mid-distal ileum and pneumatosis coli in the small bowel consistent with established infarction (necrosis or tissue death). Simon Patterson was admitted to the intensive care unit and was intubated. He received various medications including broad spectrum antibiotics.

48. Simon Patterson remained at Casey Hospital in the intensive care unit. He was critically ill and clinically very unstable, requiring multi-system support.

49. During his admission, he underwent various procedures, including:

• a. Upper GI endoscopy (camera into the oesophagus and stomach, showing segmental severe mucosal changes with discolouration in the oesophagus), laparotomy and resection (removal) of 132 centimetres of ischemic small bowel due to necrosis on 29 May 2022;

• b. A repeat gastroscopy, further exploratory laparotomy and further resection (removal) of another 40 centimetres of ischemic small bowel due to necrosis on 31 May 2022;

• c. A laparotomy for control of post-operative bleeding on 4 June 2022.

50. Various tests, scans and other investigative procedures were conducted by medical staff to determine the underlying cause of Simon Patterson's presentation. Blood cultures taken on 29 and 30 May 2022 yielded no growth (did not produce abnormal results). A faecal specimen taken on 31 May 2022 detected Clostridium difficile (C diff) toxin A/B gene but the more specific immunoassay was negative. C diff was again detected on 16 June 2022 but was negative on 23 July 2022.

51. Pathology of the resected small bowel reported extensive mucosal necrosis, consistent with shock and inadequate blood flow. No chronic disease or acute infective cause was reported, and there was no evidence of thrombosis, vasculitis, dysplasia or malignancy. The remaining small bowel, large bowel, caecum and transverse colon were healthy.

52. Ultimately, doctors were unable to determine the cause of this illness.

53. Simon Patterson was extubated on 14 June 2022. He was transferred to St John of God rehabilitation centre on 22 June 2022, following a 24-day stay in hospital. He remained in rehabilitation regaining strength after his period in intensive care until 8 July 2022. The accused offered for Simon to stay at her home while he recovered, and he stayed with her for a few weeks after being discharged from rehabilitation. During this period of time, Simon did not eat a great deal, and tended to prepare his own food so as not to be a burden. The accused would usually prepare the evening meals which they would share as a family.

54. On 14 July 2022, Simon Patterson started seeing a general practitioner, Dr Christopher Ford, who he already knew through church and bible study. Given the nature of his symptoms during the first two illnesses, Dr Ford referred Simon to a gastroenterologist, Associate Professor Christopher Mills. Arrangements were made for Simon Patterson to have weekly blood tests for a month and then fortnightly blood tests to see if a cause of the illnesses could be determined and to monitor his recovery, including his potassium levels. His first blood sample was collected the same day - 14 July 2022. No abnormalities were detected.

55. Whilst staying with the accused, Simon Patterson became ill again. On 22 July 2022, Simon and the accused ate lunch together - a beef stew with rice which the accused had prepared, and which only the accused and Simon ate. The children were not at home for lunch. At 5.19pm, the accused sent Simon a message on the Signal application, asking him to bring back the 'empty stew plate (or full stew plate if you didn't eat it)'. Simon responded that he 'certainly ate it'.

56. Shortly after midnight the following morning, 23 July 2022, Simon Patterson started vomiting and suffering from diarrhoea. He attended Leongatha Hospital and was transferred to Monash Medical Centre, where he remained for a few days. An abdominal CT scan was performed on 23 July 2022, and the results compared to the abdominal CT scan performed on 29 May 2022 (the day of his presentation to Casey Hospital). The major finding was a collection in the left upper quadrant with the anterior aspect touching the transverse colon. A repeat CT scan on 9 September 2022 showed a decrease in size in this collection. A faecal specimen was sent for testing with no abnormal results detected. Simon was then discharged on 25 July 2022 and returned to the accused's house.

57. Doctors were unable to definitively determine the cause of this illness at the time, however, the abdominal collection and the proximity of this illness to the recent admission with bowel resection with a prolonged ICU stay could result in a presentation with vomiting and diarrhoea. An infective gastroenteritis was investigated with a faecal specimen and no infective cause found.

58. Shortly after he returned to the accused's house, the accused told Simon that she resented him and regretted asking him to stay with her. Later that day, Simon Patterson packed his belongings and returned to his own home.

59. On 25 August 2022, Simon consulted with Associate Professor Mills. Associate Professor Mills spent a long time going through Simon's history, which he noted was highly unusual. The clinical history taken from Simon indicated that he had been completely well up until 2021. Associate Professor Mills had never seen a case like Simon Patterson's before. He considered Simon's presentation to be 'unique' because of the severity of the medical picture in a young person with no suggestion of pre-existing organ dysfunction. He also noted that Simon was well at the time of the consultation. Associate Professor Mills wondered whether Simon Patterson had contracted an infection called Clostridium Difficile (C diff) following a severe acute gastrointestinal illness, and considered this the most plausible answer at the time; however, noted its unusual presentation and sequelae. As a precaution, he ceased Simon's use of Pantoprazole, which is a risk factor for recurring C diff, however, he did not form a conclusive view about the cause of Simon Patterson's recurring illnesses.

Trip to Wilsons Promontory, September 2022

Charge 3 - Attempted Murder

60. After Simon Patterson returned home, he and the accused continued to have contact. In late August or early September 2022, Simon and the accused spoke on the phone. The accused suggested they catch up in person on a suitable day. Simon was pleased and encouraged, so immediately agreed. The accused suggested that they catch up during the day when the children would be at school. Simon suggested a walk at Wilsons Promontory and the accused offered to bring lunch. They made arrangements to go for a walk.

61. On the morning of Tuesday 6 September 2022, Simon Patterson did a routine stool sample for his gastroenterologist, Associate Professor Mills.

62. The same day, the accused and Simon went for a walk at Wilsons Promontory together, without the children. The accused brought them each a separate pre-packed lunch. The accused gave Simon his lunch - a pre-prepared chicken curry wrap in aluminium foil. The accused ate what appeared to be the same filling except on a plate without the wrap.

63. Shortly after eating lunch, Simon Patterson began to feel unwell. They went on a short walk on the beach before he went to the toilet with diarrhoea. He started to vomit and suffered some diarrhoea during the car trip home.

64. The accused and Simon drove to Donald and Gail Patterson's house, as they had collected [Redacted] from school. Simon continued to vomit at his parents' house, and they called an ambulance for him.

65. Inside the ambulance, Simon noticed that he started to slur his words and his muscles felt increasingly weak. He suffered a 'seizure' requiring intravenous medication for seizure termination and was in a reduced conscious state. Simon was admitted to Monash Casey Hospital intensive care unit with extremely low potassium levels. He went into polymorphic ventricular tachycardia (a potentially life-threatening heart rhythm) and was intubated. Simon received aggressive electrolyte replacement via central venous catheter through the initial hours of admission. He remained in hospital for three days as he recovered and was eventually discharged on 9 September 2022.

66. The routine stool sample which Simon had provided on the morning of 6 September 2022 before his walk with the accused was unremarkable - it indicated no obvious bacteria, parasites or inflammation in his intestines.

67. Again, his treating doctors could not determine the cause of this illness.

1. As the amended Summary of Prosecution Opening indicates the accused subsequently invited Simon Patterson, his parents, Don Patterson and Gail Patterson, and his aunt and uncle, Ian Wilkinson and Heather Wilkinson, to lunch on 29 July 2023. Simon Patterson initially accepted the invitation but, suspecting that the accused was trying to poison him, texted the accused the evening before to advise her that he would not be attending. The amended Summary of Prosecution Opening continues:

98. Meanwhile, on the morning of 29 July 2023, Heather and Ian Wilkinson had breakfast at home together alone. They met their neighbours and a friend for coffee at a local café. Later that morning, Donald and Gail Patterson picked up the Wilkinsons and they travelled together to the accused's house in Leongatha, arriving at around 12.30pm.

99. The accused greeted the guests at the door. [Redacted] were not present. The accused showed them into the dining/living area and they discussed the house, as the Wilkinsons had not been there before. They all went into the back garden, before they came inside and the accused started serving lunch, which she had been cooking before the guests arrived. The accused was in the kitchen, while Gail and Heather stood on the other side of the kitchen bench. Donald and Ian stood on the far side of the dining room table. Gail and Heather offered to help the accused in the kitchen, but she told them she had it all in hand. Neither Gail nor Heather helped to prepare or serve the meal.

100. The accused plated the meal, which consisted of individual beef wellingtons, mashed potato and green beans. The beef wellingtons were prepared as a piece of steak covered with mushrooms and completely encased in pastry. There were four large grey coloured dinner plates and one smaller plate which was lighter in colour, which Ian Wilkinson describes as tan/orange. Heather and Gail moved the four large plates from the bench to the table and the accused took the smaller lighter coloured plate to her place at the table. Donald, Gail, Ian and Heather each ate from a large grey coloured dinner plate. The accused ate from the smaller plate.

101. They said Grace and started the meal. Ian and Heather ate their entire portion. Gail ate approximately half of her serve and gave the rest to Donald, who ate his own as well as some of Gail's. There was banter amongst them about how much they had eaten. The accused also ate a beef wellington. After the main meal, they ate dessert, which consisted of a cake which Gail had brought and a fruit platter prepared by Heather.

102. After the lunch, the accused announced that she had cancer and asked for advice on whether to tell the children or keep it from them. They had a discussion about it being best to be honest with the children. They prayed as a group for the accused's health and wisdom in relation to telling the children.

1. The amended Summary of Prosecution Opening indicates that soon after the lunch, each of the guests suffered serious gastrointestinal illness, were hospitalised and were eventually diagnosed with death cap mushroom poisoning. The accused was also hospitalised but was not diagnosed with death cap mushroom poisoning. Her symptoms were mild compared to those suffered by her lunch guests. Gail Patterson and Heather Wilkinson died on 4 August 2023 and Don Patterson died on 5 August 2023. The amended Summary of Prosecution Opening continues:

RETROSPECTIVE ANALYSIS OF SIMON PATTERSON'S ILLNESSES

366. Simon Patterson's medical files were also examined by intensive care specialist Professor Andrew Bersten in 2024 to determine whether there was a unifying diagnosis across his multiple admissions to hospital between 2021 and 2022.

367. After reviewing the files, Professor Bersten noted that the cause of the gastrointestinal symptoms on each occasion, particularly in the first and second illnesses, was acute in nature (severe and sudden in onset). However, the cause itself could not be positively identified, despite reasonably extensive investigation and testing during the hospital admissions and review by various consultant physicians. Nevertheless, some potential causes could be eliminated or deemed unlikely. According to Professor Bersten:

• a. A chronic bowel condition with flare-ups leading to hospital admissions was unlikely, given extensive investigations did not reveal any significant chronic bowel between the illnesses, and after the final illness; and

• b. An infective cause of the illnesses could not be identified with negative biochemical test results returned for a range of investigations.

368. In Professor Bersten's view, Simon Patterson's second illness, which led to an extensive bowel resection and a prolonged ICU admission, complicates interpretation of the illnesses that follow. For that reason, the key focus for diagnosis as to the cause of his illnesses lies in the first and second illnesses.

Simon Patterson's First Illness (November 2021)

369. Professor Bersten noted that when Simon Patterson first presented to Leongatha Hospital on 19 November 2021, his blood tests revealed severe dehydration, acute renal impairment and modestly elevated lactate, but no evidence of acute liver damage. Two faecal specimens were separately taken from him on 21 November 2021, two days after admission. Appropriate extensive testing of these specimens was negative for faecal pathogens including Clostridium difficile. Subsequent investigations and tissue pathology did not reveal other pathologies and a colonoscopy in 2022 indicated benign polyps only. Ultimately, no infective cause of Simon Patterson's first illness was found.

370. Considering the available evidence, Professor Bersten considered that some acute cause of gastroenteritis brought about Simon's initial illness, with acute renal failure a secondary event consequent upon severe dehydration. In the absence of a pre-existing condition affecting the gastrointestinal tract, Professor Bersten opines that Simon Patterson's first illness was likely caused by either a toxic or an infective cause. Despite reasonably extensive investigation, including testing using an Ausdiagnostics Multiplex analysis (an extremely sensitive test for pathogens) no infective cause was found. This does not definitively exclude an infective cause but makes one highly unlikely. Ingestion of a toxic substance is possible; however, Professor Bersten could not suggest what that substance could be. The lack of liver damage is inconsistent with amatoxin poisoning.

Simon Patterson's Second Illness (May 2022)

371. According to Professor Bersten, Simon Patterson presented to Casey Hospital with severe shock likely due to dehydration following severe vomiting and diarrhoea. The severity of the shock and the likely subsequent mesenteric (intestinal and liver) ischemia suggest there may have been other toxic effects, however, no cause of these is found or suggested by the information available.

Professor Bersten noted that a single paediatric blood culture was taken from Simon Patterson on 29 May 2022, the day of his admission to Casey Hospital but three days after the onset of symptoms. Two more blood cultures were sent in the next 24 hours following broad spectrum antibiotic therapy. All of these blood cultures were negative. A faecal specimen sent on 31 May 2022, two days after his admission to Casey Hospital, was subjected to highly sensitive PCR testing, which detected the Clostridium difficile ('C diff') toxin A/B gene, but the more specific immunoassay was negative. A similar result was obtained on 16 June 2022 but had cleared by 23 July 2022. The significance of this result is uncertain and open to interpretation. At the time, medical professionals treating Simon considered the significance of this result to be uncertain, but given the life-threatening nature of his illness, appropriate treatment continued. If the result was significant, it is possible that it was community acquired C diff infection. However, the more likely interpretation is that the PCR result was secondary to the initial illness and broad-spectrum antibiotics, and therefore is a complication of the initial gastroenteritis. According to Professor Bersten, considering the overall circumstances of this hospital presentation, C diff is unlikely to be the primary cause of the gastrointestinal illness suffered by Simon Patterson.

373. Considering the available evidence, Professor Bersten states that the cause of Simon Patterson's second illness is uncertain. He opines that the initial gastrointestinal illness (and C diff infection, if one occurred) led to dehydration and a shock state, which in turn led to small bowel ischemia, liver ischemia and a multisystem injury including acute kidney injury. As with the first illness, in the absence of a pre-existing condition affecting the gastrointestinal tract, Professor Bersten opines that Simon Patterson's second illness was likely caused by either a toxic or an infective cause. Despite reasonably extensive investigation, other than the uncertain C diff indication, no infective cause for the illness was identified, but this could not be definitively excluded. Ingestion of a toxic substance is possible; however, Professor Bersten could not suggest what that substance could be. The pattern and rapid resolution of Simon's acute liver damage during this presentation is not consistent with typical amatoxin poisoning.

374. Professor Bersten also considered the medical records concerning Simon Patterson's re-admission to hospital on 23 July 2022. The proximity of this admission to the previous bowel resection and prolonged ICU stay, and the presence of an abdominal collection, complicate interpretation of this admission. Notably however, a faecal specimen sent for PCR testing on the day of this admission identified no pathogens, including C diff. Another faecal test on 7 September 2022 was negative on faecal multiplex including C diff, parasites and bacteria.

Simon Patterson's Third Illness (September 2022)

375 Professor Bersten noted Simon Patterson's presentation to Casey Hospital on 6 September 2022 with extremely low potassium, following an abnormal ECG and abnormal rhythm episodes on transfer via ambulance. He opined that, despite having measured blood potassium levels within the reference range following discharge from hospital on 25 July 2022, Simon Patterson had potassium depletion for weeks to months prior to the 6 September admission which was not evident from the testing. Further, the vomiting and diarrhoea earlier that day acutely depleted Simon's total potassium leading to an extremely low blood potassium, which then in turn led to the heart rhythm disturbance.

376. Professor Bersten was not able to pinpoint the cause of Simon's chronic potassium deficit, but found it was consistent with ongoing bowel losses and the bowel resection he required in May 2022. Medical professionals at the time did not investigate the cause of this episode of vomiting and diarrhoea.

1. The prosecution submitted that, taking the evidence at its highest, the evidence supported each of the alleged similarities between Events 1-4. Responding to a submission by the accused, the prosecution submitted that, in relation to similarity 7, the prosecution was not assuming what it was endeavouring to prove, namely that meals served by the accused to Simon Patterson were poisoned. Rather, the prosecution was relying on the timing of the severe illnesses, to wit, Simon Patterson and each of the lunch guests falling ill soon after eating meals prepared by the accused.
2. The prosecution submitted that the similarities between Events 1-4 were uncanny, especially having regard to the familial relationship between the accused and the alleged victims, the fact that they all fell seriously ill after eating meals prepared by the accused and the accused was accessing information on poisons before or shortly after each event. The prosecution relied on what Gibbs CJ said in Perry v R[1] (Perry) about the improbability of coincidence accounting for a series of poisonings within a suspect's circle of associates. The prosecution submitted that the uncanny similarities between Events 1-4 by themselves gave the evidence significant probative value but, when considered in combination with the other evidence on which the prosecution relied (including incriminating conduct), the coincidence evidence clearly passes the s 98 test. The prosecution submitted that any risk of unfair prejudice could be cured by directions. The jury could be expected to follow directions and not engage in rank propensity reasoning.[2]

1. The accused submitted that the evidence did not bear out each of the alleged similarities in relation to Events 1-4. In particular, the accused submitted that the evidence did not establish that the accused suggested all the trips with Simon Patterson or allocated all the meals to Simon Patterson or ate separate meals from Simon Patterson. The accused also submitted that in relation to Event 4, the accused did not allocate the meals or eat a separate meal.
2. The accused also submitted that the meals constituting Events 1-3 were not proximate to the meal constituting Event 4.
3. Even assuming the alleged similarities, the accused submitted they were unremarkable and thus, the coincidence evidence did not have significant probative value. The accused highlighted the limitations of the medical evidence in relation to Simon Patterson's illnesses: it did not exclude the real possibility that Simon Patterson suffered from infections or that Simon Patterson's illness following Event 3 was attributable to the severe illness after Event 2, as the prosecution conceded might have been the case with Simon Patterson's illness in July 2022. The accused also relied on Perry, where the High Court unanimously decided that the evidence in relation to a Mr Duncan (Mrs Perry's former de facto) did not establish that he had ever been poisoned with arsenic and ought not have been admitted as part of the similar fact evidence (which otherwise consisted of evidence of the undisputed poisoning of Mr Haag (her second husband), Mr Montgomerie (her brother) and Mr Perry (her third husband).
4. The accused submitted that if the jury determined that the accused deliberately poisoned her lunch guests, the jury was likely to have an emotional response against the accused (that is, they would misuse the evidence) and would jump to the conclusion that the accused had served poisoned meals to Simon Patterson (that is, they would overvalue the evidence). The accused submitted that directions would not cure the overwhelming prejudice.[3]

1. In conducting my analysis of the coincidence evidence, I will assume that the evidence bears out each of the alleged similarities, save for similarity 8.
2. As regards similarity 8, [REDACTED] there is no admissible evidence that at a time 'before' or 'shortly after' Event 1 (16 November 2021) the accused used a computer or other electronic device to access online content relating to poisons. While the online access on 28 April 2022 in relation to death cap mushrooms was 'before' Event 3, it was not in my view sufficiently proximate to Event 3 to be of any moment and, anyway, the medical evidence regarding Events 1-3 is that the symptoms exhibited by Simon Patterson were inconsistent with typical death cap mushroom poisoning. Accordingly, I disregard similarity 8 in assessing the probative value of the coincidence evidence.
3. Of the remaining similarities, I consider similarity 6 to be inconsequential. It is commonplace for adults to go on outings together and host lunches without children being present. That leaves the following similarities.

S.1: the accused was related by marriage to each victim.

S.2: the accused initiated/instigated each activity with Simon Patterson, and the four lunch guests, and arranged to provide/serve food.

S.3: the accused prepared the food.

S.4: the accused allocated the food.

S.5: the accused ate a separate[4] meal from Simon Patterson, and the four lunch guests.

S.7: after consumption of the food each of Simon Patterson and the four adult family relatives suffered from severe gastrointestinal illnesses.

1. It seems to me that the fact that shortly after eating meals prepared by the accused, Simon Patterson and the lunch guests suffered severe gastrointestinal illnesses (and the accused did not) is what most assists the prosecution's submission that the coincidence evidence has significant probative value.
2. I turn then to Perry, which both the prosecution and the accused relied upon. I recognise at the outset that Perry is a case decided under the common law, not Uniform Evidence Law, but one is struck by the similarity of the first step in Gibb CJ's exposition of 'similar fact evidence' law[5] to the Uniform Evidence Law requirement that coincidence evidence must possess significant probative value.
3. In Perry, there was no dispute that the alleged victim, Mr Perry, had suffered arsenic poisoning. The question was whether he may have suffered accidental poisoning through his work or had (beyond reasonable doubt) been deliberately poisoned by Mrs Perry. The similar fact evidence relied on by the prosecution was that Mrs Perry's second husband Haag and brother Montgomerie had died from arsenic poisoning. It also consisted of the evidence of one medical expert that it was possible, based on symptoms exhibited by Mrs Perry's de facto husband Mr Duncan sometime prior to his death from an overdose of sleeping tablets, that he had suffered arsenic poisoning, although no traces of arsenic were found in his system at his autopsy.
4. The Court was unanimous that the evidence in relation to Mr Duncan should not have been admitted as part of the similar fact evidence. Gibbs CJ, Murphy and Brennan JJ all considered that the evidence regarding Mr Duncan invited circular reasoning.[6] Gibbs CJ at pp589-590 said '[i]t was necessary for the Crown to rely on the other instances of poisoning, including those the subject of the present charges, in an attempt to provide a basis for an inference that Duncan had suffered from arsenical poisoning. In other words, it was necessary to assume the guilt of the applicant of the offences of which she was charged in order to render admissible the evidence regarding the death of Duncan'. Murphy J said at p595 that '... on the prosecution's theory, the supposed poisoning of Duncan depended on acceptance that Haag, Montgomerie and Perry were poisoned by the applicant, but the proof of these poisonings depended on the acceptance that she poisoned Duncan'. Brennan J said at p612 that 'the suspicion that [Duncan's] symptoms were caused by arsenical poisoning arises in part - as the Crown conceded - from the fact that Mr Perry suffered from chronic arsenical poisoning. But the mere ingestion of arsenic by Mr Perry could throw no light upon the cause of Duncan's symptoms unless it be assumed that the arsenic ingested by Mr Perry had been administered to him by Mrs Perry'.
5. Does the prosecution's coincidence evidence in the present case also invite circular reasoning? It is not in dispute that the accused prepared and provided poisoned meals to her lunch guests. What is in dispute is whether she did so deliberately. Is it necessary to first find that the accused deliberately provided poisoned meals to her lunch guests before one could find that the accused provided poisoned meals to Simon Patterson? The answer in my view is 'Yes' and, as such, the coincidence evidence does not have significant probative value.
6. Even if the coincidence evidence has significant probative value, I consider that it fails to clear the additional hurdle that is created by s 101. A finding that the accused had deliberately poisoned Don Patterson, Gail Patterson, Ian Wilkinson and Heather Wilkinson would be a finding that would create a very significant risk of the jurors misusing or overvaluing the evidence in relation to the charges concerning Simon Patterson. As regards the former risk, a striking passage in Report 26 of the Australian Law Reform Commission,[7] quoted with approval by McHugh J in Papakosmos v R,[8] bears repeating:

By risk of unfair prejudice is meant the danger that the fact-finder may use the evidence to make a decision on an improper, perhaps emotional, basis, ie on a basis logically unconnected with the issues in the case. Thus evidence that appeals to the fact-finder's sympathies, arouses a sense of horror, provokes an instinct to punish, or triggers other mainsprings of human action may cause the fact-finder to base his decision on something other than the established propositions in the case. Similarly, on hearing the evidence the fact-finder may be satisfied with a lower degree of probability than would otherwise be required.

1. Would the jurors in the present case be as rigorous in applying the criminal standard of proof as they should be, if they formed the view that the accused had deliberately and fatally poisoned Simon Patterson's mother, father and aunt and had deliberately and nearly fatally poisoned his uncle? Would the jurors be able to dispassionately assess the evidence specific to Charges 1-3 and pay full heed to the limitations of the medical evidence regarding the possible causes of Simon Patterson's severe illnesses. Moreover, would the jurors be able to resist rank propensity reasoning such as '[s]he deliberately poisoned Simon Patterson's parents, uncle and aunty: isn't it likely, then, that she deliberately poisoned Simon Patterson?' All of these dangers or risks could, of course, be the subject of directions, but the guiding principle that jurors can generally be trusted to abide by directions admits of exceptions. Even if the impugned evidence is credited with significant probative value, I am not persuaded that its probative value substantially outweighs the significant danger or risk of unfair prejudice to the accused.
2. As agreed by the parties, my ruling that the coincidence evidence is inadmissible means that there must be two trials - one in respect of Charges 1-3 and one in respect of Charges 4-7. Pursuant to s 193 of the Criminal Procedure Act 2009 (Vic), I order severance of the indictment as it would be unfair to hear all the charges together.

[1] Perry v R [1982] 150 CLR 580, 587.

[2] Prosecution Written Coincidence Evidence Submissions dated 24 January 2025; Prosecution Oral Submissions (consolidated transcript of pre-trial hearings conducted before Beale J in 2025: 1350-1395, 1419-1420).

[3] Defence Written Coincidence Evidence Submissions; Defence Oral Submissions (consolidated transcript of pre-trial hearings conducted before Beale J in 2025: 1395-1419).

[4] I understand 'separate' in this context to mean that the accused did not eat from the same 'batch' of food as Simon Patterson or her lunch guests, whether or not she ate the same type of food on the occasion in question (e.g., chicken korma curry or Beef Wellington).

[5] See Gibbs CJ at p586: '... the evidence to be admissible must have "a strong degree of probative force".'

[6] Wilson J at p607 found that the lack of clear proof that Mr Duncan suffered arsenic poisoning meant the evidence was not of sufficient probative force to be admitted as part of the similar fact evidence.

[8] (1999) 196 CLR 297, [92].