R v Somerville (No 2) - [2025] SASC 130

SUPREME COURT OF SOUTH AUSTRALIA
(Criminal)

R v SOMERVILLE (No 2)
[2025] SASC 130
Reasons for the Orders of the Honourable Justice McDonald (ex tempore)
29 July 2025
CRIMINAL LAW - PARTICULAR OFFENCES - OFFENCES AGAINST THE PERSON - HOMICIDE - MURDER - SENTENCE: PARTICULAR CASES - ATTEMPTED MURDER
CRIMINAL LAW - GENERAL MATTERS - CRIMINAL LIABILITY AND CAPACITY - DEFENCE MATTERS - INSANITY AND MENTAL IMPAIRMENT - GENERALLY
The defendant was charged with two counts of attempted murder contrary to ss 11 and 270A of the Criminal Law Consolidation Act 1935 (SA). The offences occurred on 15 August 2022, and involved the defendant stabbing both of her sons multiple times with a knife.
The defendant elected for trial by Judge alone. On 13 February 2023, the Court ordered an investigation into the defendant’s mental competence under Part 8A of the Criminal Law Consolidation Act 1935 (SA).
At the conclusion of the trial, the Court made a finding that the defendant was not guilty of the offences of attempted murder by reason of mental incompetence (s 269G B(3)(a) Criminal Law Consolidation Act 1935 (SA)) and it was therefore appropriate to declare the defendant liable to supervision under Division 4(2) of the Act (s 269G B(3)(a) Criminal Law Consolidation Act 1935 (SA)).
Having declared the defendant liable to supervision, it was necessary for the Court to order a report pursuant to s 269Q of the Criminal Law Consolidation Act 1935 (SA), addressing the diagnosis and progression of the defendant’s condition and a suggested treatment plan. The purpose of the report was to assist in determining whether to release the defendant unconditionally or make a supervision order committing her to detention or releasing her on licence conditions. It is also necessary for the Court to fix a limiting term in accordance with s 269O(2) of the Criminal Law Consolidation Act 1935 (SA).
The author of the s 269Q report concluded that it would not be appropriate for the defendant to be released on licence to live in the community, or commence accompanied leave from James Nash House, and instead, at this stage, that she should be committed to detention for ongoing treatment.
Counsel for the defence submitted that the Court should order she be released on licence, with conditions that required her to remain at James Nash House, however permitting her weekly supervised visits into the community. As a result of this submission, a further report was ordered to address the alternative proposal.
The new report maintained the original position. Having reviewed the contents of the new report, counsel for the defence no longer pressed for her to be released on licence.
In fixing a limiting term pursuant to s 269O(2) of the Criminal Law Consolidation Act 1935 (SA), the Court determined that the appropriate starting point is 15 years. That was reduced to 12 years to take into account the time that the defendant had already been detained since her admission to James Nash House on 15 August 2022.
Held:
1. The defendant is committed to detention pursuant to s 269O(1)(b)(i) of the Criminal Law Consolidation Act 1935 (SA).
2. The Court fixes a limiting term of 12 years pursuant to s 269O(2) of the Criminal Law Consolidation Act 1935 (SA).
Criminal Law Consolidation Act 1935 (SA) s 11, s 270A, s 269G, s 269C, s 269Q, s 269O, referred to.

R v SOMERVILLE (No 2)
[2025] SASC 130
Criminal

McDONALD J (ex tempore): Megan Jayne Somerville was charged with two counts of attempted murder.
On 15 August 2022, Ms Somerville stabbed both of her sons multiple times with a knife, whilst driving her vehicle on the North-South Motorway. She then stopped on the overpass at Wingfield, removed one child from the vehicle, with the other exiting himself, and again stabbed them multiple times. Both children survived, but were badly injured.
Ms Somerville elected for trial by judge alone. On 13 February 2023, I ordered an investigation into Ms Somerville’s mental competence under Part 8A of the Criminal Law Consolidation Act 1935 (SA) (‘the Act’).
At the conclusion of the trial, having heard evidence and submissions, I made the following findings:
1.The objective elements of the offences established beyond reasonable doubt (s 269G A(2));
2.Ms Somerville was mentally incompetent to commit the two offences of attempted murder, as at the time of the relevant incident, Ms Somerville was suffering from a mental impairment and as a consequence did not know that her conduct was wrong (s 269C(1)(b));
3.On the balance of probabilities, Ms Somerville’s mental impairment at the time of the conduct giving rise to the offences was substantially caused by self-induced intoxication (s 269C(2));
4.Despite my third finding, and having taken the relevant factors into account, it is appropriate that Ms Somerville be dealt with under Part 8A of the Act (s 269C(3));
5.Ms Somerville is not guilty of the offences of attempted murder by reason of mental incompetence (s 269G B(3)(a));
6.It is appropriate to declare Ms Somerville liable to supervision, under Division 4(2) of the Act (s 269G B(3)(a)).
Having declared Ms Somerville liable to supervision, it was necessary for me to order a report pursuant to s 269Q of the Act. This section relevantly provides:
269Q—Report on mental condition of defendant
(1)If a defendant is declared to be liable to supervision under this Subdivision, the Minister must, within 30 days after the date of the declaration, prepare and submit to the court by which the declaration was made a report, prepared by a psychiatrist or other appropriate expert, on the mental condition of the defendant containing—
(a) a diagnosis and prognosis of the condition; and
(b) a suggested treatment plan for managing the defendant's condition.
…
The purpose of ordering such a report was to obtain the professional assistance of an appropriately qualified psychiatrist, in determining whether to release a defendant unconditionally, or make an order (a supervision order), committing the defendant to detention or releasing the defendant on licence on conditions.
It is also necessary for me to fix a limiting term in accordance with s 269O(2) of the Act.
A limiting term is the equivalent to the period of imprisonment or supervision (or the aggregate period of imprisonment and supervision) that would, in the Court’s opinion, have been appropriate if the defendant had been convicted of the offence of which the subjective elements have been established.
Dr Haeney’s s 269Q Report
The s 269Q report was prepared by Dr Owen Haeney. Dr Haeney had previously provided a report addressing Ms Somerville’s responsiveness to treatment for her schizophrenia whilst in James Nash House. The treatment resistant form of schizophrenia, which Ms Somerville suffers from, was a relevant consideration as to whether Ms Somerville should be dealt with under Part 8A of the Act, despite the finding that her mental incompetence was substantially caused by self-induced intoxication.
Dr Haeney remains Ms Somerville’s treating psychiatrist.
In the s 269Q report, Dr Haeney summarised Ms Somerville’s progress since she was admitted on 16 August 2022. He said that initially she remained extremely agitated, with strong persecutory ideas similar to those that she held at the time of her arrest.
Given the persistence of Ms Somerville’s symptoms, long after intoxicants had passed from her system, and despite treatment with antipsychotic medication, she was commenced on clozapine in late September 2022. This is a medication specifically used for treatment resistant schizophrenia. She also received psychological therapy and occupational/sensory input to assist her with her ruminations and the effects of complex trauma.
Ms Somerville improved, becoming less irritable, less labile and less preoccupied with her beliefs. On that basis, she was able to progress from the acute admission ward to a subacute ward on 19 September 2022, then to a rehabilitation ward on 26 April 2023. Nonetheless some of her delusions persisted. Although clearly less preoccupied than she had been on examination, Ms Somerville retained many of the same beliefs about her ex-partner abusing her children, with police and the Department for Child Protection complicit.
Dr Haeney described that there was a manifest conflict between Ms Somerville’s overarching belief that she was unwell at the time of the offences (and therefore hoping for a mental impairment defence), whilst simultaneously maintaining the vast majority of the component beliefs that she held were true and not delusional.
On 26 March 2024, Ms Somerville’s medication was augmented with another antipsychotic medication, given her residual symptoms.
Dr Haeney reported that, since then, there has been a gradual improvement. By the end of 2024, Ms Somerville demonstrated improved ability to reflect on the beliefs that were present at the time of the offences, no longer as convinced that she had irrefutable evidence of wrongdoing, and accepted that some elements may have been related to her illness.
In Dr Haeney’s view, Ms Somerville has largely managed well within the rehabilitation ward, and has received psychoeducation about her illness and borderline personality disorder. However, on occasions she can be overcritical with less abled peers, but tends to respond to staff members. Occasionally, Ms Somerville is still prone to interpret events in a conspiratorial manner.
Ms Somerville was interviewed for the s 269Q report on 29 May 2025. Overall, she indicated that she was doing as well as could be expected. She unsurprisingly ruminates over her children and their wellbeing, and continues to experience significant trauma, suffering regular flashbacks.
In the interview Dr Haeney asked Ms Somerville to reflect on her mental state at the time of her arrest and her progress since. Although she initially acknowledged that she was unwell at the time and her views were “distorted”, on further questioning it became apparent to Dr Haeney that Ms Somerville continued to hold many of her previous beliefs. With regards to the substance of the allegations she had made, she thought it was “more truth than not truth”. By way of example, she was adamant that she knew that her children were not going to kill her, but when asked about the many allegations that she made about her ex-partner she responded that it was all true.
I turn then to the issue of diagnosis and prognosis which s 269Q requires Dr Haeney to specifically address.
Diagnosis
In terms of diagnosis, Dr Haeney reported:[1]
Ms Somerville had a historical diagnosis of Bipolar Affective Disorder, a chronic mental illness characterised by periods of depression and mania (pathologically elevated mood). However, during the current admission, her diagnosis has been re-conceptualised as either schizophrenia (a psychotic mental illness associated with delusions and hallucinations) or schizoaffective disorder (whereby schizophrenia symptoms and mood disorder occur concurrently).
Additionally, Ms Somerville has displayed evidence of substance use disorder, primarily relating to cannabis and methylamphetamine. Borderline Personality Disorder (or strong traits) have also been observed, such as instability of mood (but not amounting to depression or mania), impulsivity, intense interpersonal relationships and threats of self-harm. There is also evidence of Post-Traumatic Stress Disorder (PTSD) arising from her own chronic trauma but more acutely from the memories of her offence.
(Emphasis in original)
[1] Report of Dr Owen Haeney dated 30 May 2025 at [5.2]-[5.3].
Dr Haeney expressed the view that “[w]hile mindful of [Ms Somerville’s] previous diagnosis of Bipolar Affective Disorder, her current presentation is more in keeping with the chronic schizophrenia. She has residual delusions occurring in the absence of evidence of mood disorder or substance misuse. Nonetheless, given her history, she will clearly also need treatment to ensure stability of mood”.[2]
[2] Report of Dr Owen Haeney dated 30 May 2025 at [5.5], Emphasis in original.
Prognosis
On the question of prognosis, Dr Haeney said:[3]
It is more difficult to speculate on Ms Somerville’s prognosis. She has both positive and negative prognostic indicators. There has been some response to treatment, with improvement in mental state, but the persistence of elements of her delusions is more concerning. It is also important to acknowledge that while elements of her beliefs are clearly delusional, it is more difficult to know whether there is any veracity to aspects of her claims. Ms Somerville retains excellent occupational functioning. She is expected to engage well in future psychological therapy on an individual and group basis. However, she will need to show substantial resilience, given the long-term impact of her offending on herself, her children and her family. This will not be easy for her to endure and there are extensive deficits in personal support.
[3] Report of Dr Owen Haeney dated 30 May 2025 at [5.6].
In Dr Haeney’s view, Ms Somerville’s illness “is expected to follow a chronic course and she will need close monitoring, in hospital and in the future in the community, in order to support her, identify and prevent deterioration and avoid recurrence of illicit drug and alcohol use. Her progress is likely to be cautious and gradual as a result”.[4]
[4] Report of Dr Owen Haeney dated 30 May 2025 at [5.7].
Treatment plan
Dr Haeney explained Ms Somerville will have significant treatment needs moving into the future:[5]
Ms Somerville has had substantial treatment during her near three years in hospital. The most critical element is consistent medication, comprising clozapine (for treatment-resistant schizophrenia), antipsychotic augmentation and mood stabilising medication. Also vital has been psychological input (to support and educate her, now turning to address her own trauma and offence), occupational and social therapy and nursing care.
All of these elements are ongoing. Further adjustments to antipsychotic medication are probable. There will be blood tests to ascertain her clozapine level and ensure compliance. Psychological treatment will address her PTSD symptoms and then seek to improve her understanding of her illness, her need for treatment and the associated risk, as well as developing appropriate coping strategies.
[5] Report of Dr Owen Haeney dated 30 May 2025 at [5.8]-[5.9].
It is Dr Haeney’s view that given the enormity of Ms Somerville’s offences, and the residual symptoms that are still evident, it would not be appropriate to consider release on licence to live in the community, or commence accompanied leave from James Nash House. Dr Haeney respectfully requested that Ms Somerville be committed to detention for ongoing treatment. He said this is the safest and most appropriate way of managing her condition and associated risks.
Counsels’ submissions
It was the Director’s submission that I make the order for detention as recommended by Dr Haeney, noting that it would not preclude Ms Somerville making an application to vary the supervision order at an appropriate time in order to transition back into the community.
Counsel for Ms Somerville, Mr Powell, put forward an alternative proposal to detention. He suggested that I order that Ms Somerville be released on licence but with conditions that required her to remain at James Nash House. It was submitted that the only practical difference between this course, and making an order for detention, was that it would enable the inclusion of a condition whereby Ms Somerville would be permitted to take supervised outings from time to time so that she could reintegrate back into the community.
In support of that proposal, Mr Powell relied on Ms Somerville’s behaviour since she was admitted to James Nash House. He submitted that since that time there has been no issue, incident or episode that would suggest that she poses any risk to public safety. In particular, there is no record of anger, hostility, aggression or violence.
Whilst Mr Powell accepted that Ms Somerville retains some of her delusional beliefs, and that she will require a long period of treatment, he submitted that she should not need to reach a symptom-free state before her release on licence is considered. Ms Somerville has made progress since she has been at James Nash House. She has been compliant with her medication. It was contended that in those circumstances, it is now time to permit Ms Somerville to leave James Nash House for short periods.
The Director opposed Ms Somerville’s release on licence and, as I have said, submitted that I should order that Ms Somerville be committed to detention.
Dr Haeney’s addendum report
Given the submissions made by Mr Powell, I ordered that Dr Haeney provide a further report, addressing the alternative proposal that was put forward.
I have now received that report. In the report, Dr Haeney explained that the reason for his initial recommendation that Ms Somerville be committed to detention was her “treatment resistant schizophrenia complicated by borderline personality disorder, her residual symptoms and the nature of her offence”.[6]
[6] Report of Dr Owen Haeney dated 24 July 2025 at [3.1].
Having reviewed the transcript of the submissions made by Mr Powell, Dr Haeney’s opinion did not change. He explained:[7]
The decision to commence accompanied leave … is a nuanced clinical decision. While time spent in hospital and presentation on the ward may be considered, these factors must be balanced against others, including residual risk-related symptoms, work undertaken to address future risk and resilience against deterioration. In Ms Somerville’s case, she has residual symptoms of psychosis that directly underpinned her index offences. She has yet to complete the necessary psychological work to further her understanding of her illness and its relationship to her offending. Further treatment, whether pharmacological or psychological, has the potential to destabilise her mental state and increase risk.
[7] Report of Dr Owen Haeney dated 24 July 2025 at [3.3].
In his addendum report, Dr Haeney also addressed the question of the risk posed by Ms Somerville. He said:[8]
Risk must be considered holistically, rather than being a restricted interpretation of whether an individual would behave violently in a particular situation at a narrow point in time, such as being accompanied by staff in the local area today or tomorrow. It involves consideration of whether an individual is ready to commence a leave process, their level of understanding of their illness and risk, the likelihood of deterioration and whether they would recognise and appropriately manage any deterioration in mental state. There is no dispute that use of leave is a vital factor in maintaining function, assessing progress and preparing a person for eventual discharge, but in my opinion it is too soon to commence this for Ms Somerville. With offences of this severity, there will appropriately be a conservative approach in order to protect the public, protect the accompanying staff and avoid difficult situations whereby judgments have to [be] made to continue or cease accompanied leave whenever there is a change in mental state.
[8] Report of Dr Owen Haeney dated 24 July 2025 at [3.4].
The argument mounted by Dr Haeney in support of an order for detention is compelling and considered. Importantly, he is Ms Somerville’s treating psychiatrist who is uniquely qualified to assess her current status.

It was therefore unsurprising, that having received Dr Haeney’s report and having had an opportunity to reflect on its contents and take instructions from Ms Somerville, Mr Powell no longer pressed for Ms Somerville to be released on licence at this point in time.
In my view, the only appropriate order is that Ms Somerville be committed to detention. In due course it will be open to her to make an application for release on licence when her risk to the safety of the community is reduced to an acceptable level.
The limiting term
That then brings me to the fixing of a limiting term.
A limiting term is not a sentence, however it is nonetheless to be fixed by reference to a hypothetical sentencing exercise. This exercise is to be undertaken excluding any consideration of the mental element of the offence.
The maximum penalty for attempted murder is life imprisonment or some lesser term.
Relevant matters to be taken into account in fixing a limiting term for Ms Somerville include her family and social circumstances, her lack of criminal antecedents, the circumstances and objective seriousness of the offences, the time that Ms Somerville has already spent incarcerated, and the impact to the victims of her offences.
In my view, taking all of these matters into account, the appropriate starting point for the limiting term is 15 years. Given that there is no power to backdate a limiting term, I take into account the time that Ms Somerville has already spent at James Nash House since her admission on 15 August 2022. I reduce the term by three years to approximate and reflect that time. The limiting term that I fix is 12 years.