Delaney v R [2025] NSWCCA 76 | Case summary

Medium Neutral Citation: Delaney v R [2025] NSWCCA 76

Hearing dates: 14 May 2025

Date of orders: 13 June 2025

Decision date: 13 June 2025

Before: Harrison CJ at CL at [1]
Davies J at [2]
Weinstein J at [91]

Decision: 1. Extend time for the filing of the Notice of Appeal to 28 November 2024.
2. Grant leave to appeal.
3. Uphold the appeal.
4. Quash the conviction.
5. Grant leave to the appellant to withdraw his plea of guilty to the murder of Gabriella Delaney.
6. Remit the matter to the Supreme Court for retrial.
7. Stand into the Arraignments List in the Supreme Court on 4 July 2025.

Catchwords: CRIME – appeals – appeal against conviction – miscarriage of justice – where the applicant pleaded guilty to the murder of his sister – where the applicant was under the influence of drugs at the time of the offending – where the applicant was diagnosed with schizophrenia – where the applicant entered his plea on the basis of advice that the applicant did not meet the definition of “mental health impairment” – whether the advice was wrong and thus constituted a miscarriage of justice – whether the applicant’s impairment at the time of the offending was “solely caused” by drug ingestion – where none of the expert evidence engaged with the “caused solely by” test – the advice given to the applicant was wrong – conviction set aside
STATUTORY INTERPRETATION – whether the Crown bears the onus of demonstrating that s 4(3) of the Mental Health and Cognitive Impairment Forensic Provisions Act 2020 (NSW) applies – where s 4(3) provides an exception or a qualification to what is contained in s 4(1) – where the Crown asserts no mental health impairment by reason of ingestion of drugs or substance use disorder the Crown bears the onus of proof under s 4(3)

Legislation Cited: Crimes Act 1900 (NSW) s 23A
Criminal Appeal Act 1912 (NSW) s 6
Mental Health and Cognitive Impairment Forensic Provisions Act 2020 (NSW) ss 4, 14, 28, 36

Cases Cited: Dowling v Bowie (1952) 86 CLR 136
Fang v R (2018) 97 NSWLR 876; [2018] NSWCCA 210
Layt v R [2020] NSWCCA 231
R v De Souza (1997) 41 NSWLR 656
R v Delaney [2022] NSWSC 1327
R v Falconer (1990) 171 CLR 30; [1990] HCA 49
R v Jawid [2022] NSWSC 788
R v Miller [2022] NSWSC 802
R v Murray [2024] NSWSC 503
R v Patterson (No 6) [2024] NSWSC 458
R v Radford (1985) 42 SASR 266; (1985) 20 A Crim R 388
R v Sheridan [2022] NSWSC 1669
RE v R [2024] NSWCCA 180
Sagiv v R (1986) 22 A Crim R 73
TKWJ v The Queen (2002) 212 CLR 124; [2002] HCA 46
Waters and Others v Mercedes Holdings Pty Ltd and Others [2012] FCAFC 80; (2012) 289 ALR 489
White v R (2022) 110 NSWLR 163; [2022] NSWCCA 241
Xie v R [2021] NSWCCA 1; (2021) 386 ALR 371

Texts Cited: Nil

Category: Principal judgment

Parties: Lucas Delaney (Applicant)
Crown (Respondent)

Representation: Counsel:
Mr S Buchen SC with Ms C O’Neill (Applicant)
Ms K Jeffreys (Respondent)
Solicitors:
Legal Aid NSW (Applicant)
Office of the Director of Public Prosecutions (Respondent)

File Number(s): 2020/171177

Publication restriction: Nil

HEADNOTE

[This headnote is not to be read as part of the judgment]

On 22 April 2022 the applicant, Mr Lucas Delaney, pleaded guilty to the murder of his sister, Gabriella Delaney, on 3 June 2020. He adhered to that plea in the Supreme Court on 3 June 2022. The applicant was sentenced by Garling J to imprisonment for 21 years commencing 9 June 2020 and expiring 8 June 2041 with a non-parole period of 15 years 9 months expiring 8 March 2036.

The applicant and the deceased lived together as the sole occupants of a detached flat at Cambridge Park. Two other family members lived in the main house and another unit on the property. In the afternoon of 3 June 2020, their cousin, Jayleb, had an entirely normal interaction with the applicant and the deceased. Later that afternoon the applicant repeatedly struck the deceased with a hammer, causing fatal injuries. The applicant struck the blows with an intention to kill the deceased. The applicant wrapped the deceased’s body in a blanket on his bed before placing an armchair on top of the deceased’s body. The applicant then left the property. Over the next few days, the applicant stayed in several locations, consumed numerous drugs and transferred money from the deceased’s bank account to his own. On 7 June 2020, the applicant presented himself to Cumberland Hospital where he was voluntarily admitted in connection with his drug use. The deceased’s body was discovered in the flat on 8 June 2020. On 9 June 2020 the applicant was arrested and taken into custody from Cumberland Hospital.

The applicant’s lawyers arranged for the forensic psychiatrist, Dr Adam Martin, to provide a report on the availability of a defence of mental health impairment pursuant to s 28 of the Mental Health and Cognitive Impairment Forensic Provisions Act 2020 (NSW). Dr Martin concluded that a defence of mental health impairment was not available despite diagnosing the applicant with schizophrenia because acute intoxication could not be excluded as “the most important factor” to the offending. The Crown’s expert, Associate Professor Anthony Samuels, reached a similar conclusion. Based on that advice the applicant’s lawyers advised the applicant that they would have to exclude drug use on his part to be able to rely on the defence of mental health impairment. In reliance on that advice the applicant entered a plea of guilty to murder on 22 April 2022.

The applicant sought leave to appeal against his conviction on one ground:

Ground 1: A miscarriage of justice occurred because the applicant’s plea of guilty to murder was entered on the basis of expert opinion evidence and legal advice that was mistaken about the definition of “mental health impairment” in Section 4 of the Mental Health and Cognitive Impairment Forensic Provisions Act 2020 (NSW)

The applicant also sought leave to appeal against his sentence on one ground:

Ground 2: The learned sentencing judge erred in his consideration of the applicant’s mental state at the time of the offence.

As the applicant’s appeal against his conviction was allowed it was not necessary to consider the appeal against sentence.

The Court (per Davies J, Harrison C****J at CL and Weinstein J agreeing) held, upholding the appeal and setting aside the conviction**:**

As to Ground 1:

(1) The test in s 4(3) of the Mental Health and Cognitive Impairment Forensic Provisions Act 2020 (NSW) is whether the relevant impairment was “caused solely by” drug ingestion and cannot be equated to a “but for” test. Neither Dr Martin nor Dr Samuels properly engaged with the test in s 4(3). Both doctors considered that the applicant suffered from schizophrenia. Both doctors also concluded that both drug ingestion and schizophrenia were factors in the offending. Neither doctor stated that the mental health impairment at the time of the offending was caused solely by drug ingestion but yet advised that a defence of mental health impairment was not available. Therefore, the advice given to the applicant, that the defence under s 28 was not available, was wrong and deprived the applicant of the chance of a special verdict: [63]-[73] (Davies J); [1] (Harrison CJ at CL); [91] (Weinstein J).

Fang v R (2018) 97 NSWLR 876; [2018] NSWCCA 210; R v De Souza (1997) 41 NSWLR 656; R v Murray [2024] NSWSC 503; R v Patterson (No 6) [2024] NSWSC 458; TKWJ v The Queen (2002) 212 CLR 124; [2002] HCA 46*,* cited.

(2) The Court held that where the Crown asserts that there is no mental health impairment by reason of ingestion of drugs or substance use disorder the Crown bears the onus of proof under s 4(3). As s 4(3) is an exception or qualification to s 4(1), this conclusion is also consistent with the principle that the party relying on an exception bears the onus of proof: [74]-[89] (Davies J); [1] (Harrison CJ at CL); [91] (Weinstein J).

Dowling v Bowie (1952) 86 CLR 136; R v Falconer (1990) 171 CLR 30; [1990] HCA 49; R v Jawid [2022] NSWSC 788; R v Miller [2022] NSWSC 802; R v Murray [2024] NSWSC 503; R v Patterson (No 6) [2024] NSWSC 458; R v Radford (1985) 42 SASR 266; R v Sheridan [2022] NSWSC 1669; Waters and Others v Mercedes Holdings Pty Ltd and Others [2012] FCAFC 80; (2012) 289 ALR 489*,* cited.

Judgment

HARRISON CJ AT CL: I agree with Davies J.
DAVIES J: On 22 April 2022 in the Penrith Local Court the applicant pleaded guilty to the murder of his sister, Gabriella Delaney, on 3 June 2020. He adhered to that plea in the Supreme Court on 3 June 2022.
On 19 October 2022 he was sentenced by Garling J to imprisonment for 21 years commencing 9 June 2020 and expiring 8 June 2041 with a non-parole period of 15 years 9 months expiring 8 March 2036: R v Delaney [2022] NSWSC 1327.
The applicant now seeks leave to appeal against his conviction on the following ground:

A miscarriage of justice occurred because the applicant’s plea of guilty to murder was entered on the basis of expert opinion evidence and legal advice that was mistaken about the definition of “mental health impairment” in Section 4 of the Mental Health and Cognitive Impairment Forensic Provisions Act 2020 (NSW).

Leave is sought because the appeal is brought pursuant to the third limb of s 6(1) of the Criminal Appeal Act 1912 (NSW).
The applicant also seeks leave to appeal against his sentence on the following ground:

The learned sentencing judge erred in his consideration of the applicant’s mental state at the time of the offence.

The applicant requires an extension of time to appeal because the Notice of Appeal was not filed until 28 November 2024. A Notice of Intention to Appeal had been filed on 1 February 2023.
For the reasons which follow the applicant should be granted an extension of time to appeal, his appeal against his conviction should be allowed, and the matter remitted to the Supreme Court for retrial. In the circumstances it is not necessary to consider the appeal against sentence.

The Offending

The applicant was sentenced on the basis of agreed facts which were summarised by the sentencing judge.
The applicant and the deceased, who were biological siblings, lived together as the sole occupants of a detached flat at Cambridge Park. Their brother, Daniel, and his wife, Ms Tompkins, lived in the main dwelling house on the same property. The applicant’s cousin, Jayleb, lived in another unit on the property.
On 3 June 2020, Jayleb came home from work between 3:30pm and 4:00pm. He went into the flat and spoke with the applicant and the deceased for five to ten minutes before leaving to go to his unit on the property. That interaction was entirely normal.
Later that afternoon, after Jayleb left the flat, the applicant repeatedly struck the deceased in the head with a hammer, causing fatal injuries. As a result of the blows, the deceased suffered extensive fractures to her skull and face. The applicant’s assault on the deceased also caused bruising to her arms and legs, broken upper and lower front teeth, lacerations to her neck, and on the top of her skull. The applicant at the time he struck the blows did so with an intention to kill the deceased.
The applicant wrapped the deceased’s body in a blanket on his bed. He took a single armchair from the living room and placed it upside down on the bed, on top of the deceased’s body.
The applicant went to Jayleb’s unit and said he would be going “out for a couple hours, days”. Jayleb suggested he would go and see the deceased, to which the applicant responded that she had gone to a friend’s place. The applicant also refused Jayleb’s offer to care for their dogs while he was away.
That night, the applicant went to a friend’s house and smoked methamphetamine. He did not sleep. The following day, he checked into a motel where he stayed the night.
The applicant then caused $5,300 to be transferred from the deceased’s bank accounts to his bank account. Over the next few days, he withdrew a further $4,000 in cash and paid for two nights’ accommodation out of this money.
On 4 June 2020, Jayleb attempted to contact the deceased. Ms Tompkins entered the flat and called out to the deceased and the applicant, but she received no answer. Ms Tompkins noticed that the dogs were locked in the flat.
On 5 June 2020, the applicant went back to the flat, showered and changed his clothes. He left, and subsequently encountered Ms Tompkins along the road, who commented on his absence from the property. He dismissed her comments and said he would be away for a number of days.
The applicant checked into a hotel, where he met two friends, with whom he smoked ice and cannabis.
On 6 June 2020, the applicant again stayed away from the flat in a different motel.

Psychiatric Reports

The lawyers acting for the applicant arranged for the forensic psychiatrist, Dr Adam Martin, to interview the applicant and to provide a report on the availability of a defence of mental health impairment pursuant to s 28 of the Mental Health and Cognitive Impairment Forensic Provisions Act 2020 (NSW) (“MHCIFP Act”). Dr Martin interviewed the applicant on 20 September 2021 and provided his report on 3 December 2021. In the report, Dr Martin relevantly said:

Mr Delaney told me that he had smoked cannabis from the age of fourteen and previously smoked on a daily basis in large amounts, between 30-40 cones per day. He said that he has previously smoked synthetic cannabis heavily, over four years, up to 2015. He said that he had used methamphetamine ["ice"] over the last three years and for a period of one year smoked on a daily basis before reducing to just weekend use. Regarding other drug use, he said that he had used cocaine occasionally as well as MDMA [Ecstasy]. He said that he had smoked heroin once. He denied use of LSD or magic mushrooms. He described previous phases of daily and heavy alcohol use but over the last few years had only drunk more occasionally. He said that he attended drug and alcohol counselling in WA in a "smart group”, but denied periods of residential rehabilitation or detoxification.

…

Account of Alleged Offending

Mr Delaney gave an account of believing that he had been smoking cannabis with a person, saying "I thought it was someone I'd met on line". He said that he told him to go, but that the other person said "we've got heaps of smoke left, I don't want to". He said "I waved a tool at him – the person went from a normal looking person to really tall, his eyes were fire red, the room went black, I started swinging the tool at him, I could feel it go through him, he was laughing, I realised and looked down and saw it was my sister sitting on the couch". From what I could ascertain, Mr Delaney was given [scil. giving] an account of at the time believing he was smoking cannabis with a person who was not real. He said that he had assumed that he had met them online. In relation to the alleged offending, he said that he could remember the person walking back through a projector screen and glass wall "like a ghost''. He said that he then "freaked out, went to the bathroom, I don't know what happened -- it's blank until I was in the hotel". In the hotel, he said because of a disturbed state of mind that "I thought the best thing to do was to get to safety in hospital, for medical attention - didn't know I'd killed her until the police arrived".

On direct questioning, he said that he could not recall whether he had used methamphetamine but said "I know I had ice in my possession". He said that he did not think that he had used methamphetamine just before the alleged offending saying that he generally did not smoke it at his home and would only smoke it at others' houses.

…

He described a poor memory for the time following the alleged offending after going to psychiatric hospital but said that he could remember waking up in the hotel "in a freaked out state of mind". He said that he had been worried that freemasons were after him and that he had tapes of their initiations which had been obtained surreptitiously, saying "someone put a recorder on their body – they were given to me about five years before – it was privileged information". In the hotel, he said that he had thought that cousins were trying to get in and he said "it wasn't logical”. In hospital, he said that his mental state had been "very scattered, still hearing voices - everyone had the same voice”. He said that he thought he had used methamphetamine a week or two before the alleged offending, but had been smoking cannabis on most days for several years prior.

…

Opinion

In terms of diagnosis, in my view, it is probable that Mr Delaney does have ongoing psychotic phenomena despite being in a relatively controlled environment and taking anti-psychotic medication, and in my view, on balance, he can be diagnosed with schizophrenia. Schizophrenia is known to be a major mental illness and characterised by a predisposition to experience of psychotic phenomena. Psychosis is a description of a person being 'out-of-touch with reality', as manifested by experience of delusions [fixed false beliefs], hallucinations [perceptions in the absence of external stimuli], thought disorder [breakdown in coherence of expressed thought and communication] and disorganised behaviour. Schizophrenia and its related disorders are frequently precipitated, triggered, perpetuated and exacerbated by substance use, particularly methylamphetamine. There is clear documentation in the collateral information of a lengthy history of substance use leading to disorganised behaviour with Mr Delaney. He has a diagnosis of substance use disorder [cannabis and methylamphetamine].

Regarding the salient issue of whether he has the defence of mental health impairment pursuant to Section 28 of the Mental Health and Cognitive Impairment (Forensic Provisions) Act 2020, I found the following:

The issues are complex, as while he on balance has a serious mental health impairment [schizophrenia complicated by substance use], firstly, the issue of acute intoxication with methylamphetamine cannot be excluded as the most important factor being relevant to the alleged offending, on the assumption that the physical offending occurred as alleged. In short, acute intoxication with methylamphetamine could lead to a person being highly paranoid, agitated, angry and disinhibited. Given that he appears to be functioning reasonably well in the time before the fact, and to be apparently interacting appropriately with his sister according to the CCTV evidence for instance, in my view, the physical act appears to have been most likely in the context of acute drug use causing a transient severe disturbance of behaviour. Furthermore, based on the available information, it is not possible to state that he did not know the nature and quality of his act, or was unaware of the wrongfulness of his behaviour as a result of mental health impairment [as opposed to the effect of acute intoxication], or that he would have been unable to reason with moderate composure. The argument that he was significantly impaired by chronic mental illness to the extent that he would have not been able to appreciate the wrongfulness of his behaviour or been able to reason with moderate composure would be speculative. To this end, in my view, the proposition that he has the availability of the defence of mental health impairment available to him is contentious and problematic.

In formulation, Mr Delaney clearly has severe psychological problems with a probable diagnosis of schizophrenia, a major mental illness, complicated by chronic substance use disorder, with a background of limited psychosocial functioning and poor coping skills. Essentially, he has a drug addiction, and has presented with features of major mental illness such as reporting of hallucinations and paranoid beliefs. The offending as alleged appears to have occurred in direct nexus to the effects of drug addiction affecting his level of control and judgment. Unfortunately, it is not possible to know exactly how his mental state at the material time caused the physical act as alleged, but in my view, it can be assumed to have been the end product of drug addiction and intoxication affecting his thought processes and impairing his ability to behave rationally.

No spontaneous expressions or remorse were made. It was difficult to form a confident opinion in relation to his mental state at the time of the offending although, in my view, it is more likely than not that he was significantly paranoid in the time following the alleged offending, given his moving between motels and descriptions of concern about Freemasons' recordings for instance, which appeared to be of a genuinely paranoid nature.

(emphasis added)

On 9 December 2021 following receipt of Dr Martin’s report, the applicant conferred with his solicitor and counsel via AVL from custody. The solicitor’s notes of that conference disclose the following:

Points of discussion:

procedure

brief of evidence

psychological report

plea of guilty

Psychological report from Dr Martin

· Sought an expert opinion to see if there Is a defence of mental illness is available

· History of mental Illness

· History of drug abuse

· Report required a lot of time to obtain

· Needed time to prepare the report as it was necessary to progress the matter

· Questions to the psych. What mental Illness, role in the death, was the role to a degree you could plea [sic] guilty to mental illness

· Psychiatrist has come to an opinion

· The expert has a background in dealing with these Issues

· Mental health impairment –

· Drug use cannot be excluded as an important part to the commission of the crime

· Acute use of methamphetamine — disinhibited

· History of schizophrenia and cannabis

· Defendant confirmed he has problems recalling the events leading up and during the offence.

· At time of commission of offence in the course of a drug induced psychosis

· In report did not recall to psychologist of using the methamphetamine in possession

· Evidence is days after the offence using methamphetamine

· Concerns that he wasn't prescribed appropriately. Concerns not treated properly.

· We do not have the defence to plea the defence of mental illness

· The schizophrenia could not be separated from the offence.

· Advised would have to prove that he was not taking drugs

· Confirmed all information provided to the psychologist was true and accurate

· Lucas raised concerns that he has mental health issues that are longstanding

· Explained that there is no doubt of the mental health issues, it is different to the defence being available

· We would have to exclude the drug use at the time as a contributing factor and the doctor cannot separate the two

· Dr Martin says schizophrenia is trigged [scil. triggered] or exacerbated with drug use

· There is evidence that he was using drugs

· Long term history of drug use

· We will need to determine if you are pleading guilty or not guilty

· We have explored the medical Issue

· Terminated AVL at 1:305pm. Client has a copy of signed instructions, crown case statement and psychological report. Advised to read all material ahead of our next conference on 15 December 2021. Advised defendant to consider the plea he wishes to enter. Advised the defence is not available and will discuss all aspects of the case again.”

(emphasis added)

There were subsequent conferences between the applicant and his lawyers on 10, 13 and 15 December 2021 and 10, 12 and 21 January 2022. The notes of those conferences disclosed that the applicant understood that a mental illness defence was not available, that the mental health issues would be relevant to sentence and instructions were given to try to negotiate a plea to manslaughter. The applicant was advised about the discount for an early plea.
On 8 March 2022 the Office of the Director of Public Prosecutions served a report from Associate Professor Anthony Samuels. Dr Samuels interviewed the applicant on 24 February 2022.
Dr Samuels’ report of 24 February 2022 relevantly said:

Drug and Alcohol History

Mr Delaney said he smoked marijuana regularly. There was a period in Western Australia where he smoked ICE. When he returned to NSW in 2019 he was smoking marijuana regularly and occasionally using ICE, once every two months. He denied any other drug use. He said he had tried synthetic cannabis in the past, about three years ago. He also tried Ecstasy and cocaine but never heroin or LSD.

He denied significant alcohol use.

…

History of the Offence

Mr Delaney said he was living with his sister for nine months. He was very close to her. At one stage when they were in Western Australia she moved in with him. She had moved back to NSW a few years earlier. He came back partly to see her but also to see his other siblings and people that he knew. Mr Delaney had worked a few days before the offence. He was smoking marijuana regularly after work to relax. He might have used ICE a week or so before the offence but he was not entirely sure. He said he never used ICE at home and if he used ICE he would go to a hotel or some other place. After his return to NSW Mr Delaney was not on any psychotropic type medications.

I asked Mr Delaney about his memories of what happened on the day of the offence. He said he can remember parts of what happened. His main memory is of waking up in a hotel in Parramatta. He said he remembers being at home and thinking that there was someone else there. He was smoking marijuana. He was tired and he wanted to get to bed and he was trying to get this person to leave. He said he got the person to follow him to the front door but then they stayed in the house. He said this person got angry at him, the person changed from a normal person to "a tall person like a demon". He said this person was able to walk through walls and through the furniture. Mr Delaney said there were tools behind the couch, he grabbed them and hit the "demon" with them. The demon just laughed and was not affected by this. He was shocked and confused but felt he was hitting the demon. He said during this period his sister had been asleep on the couch and was unaware that he was arguing with this "personage". At this point in the interview Mr Delaney looked down, placed his head in his hands and seemed quite distressed but he recovered not long after that.

I asked Mr Delaney who this person might have been and he said, "I assumed it was someone I met online".

He said he "came to" in a hotel. He remembered hearing voices. He thought people were playing tricks on him and had "set me up". He said when the sun came up he thought he would go to Cumberland Hospital because he felt safe there, he acknowledged feeling "paranoid". He thought Freemasons were following him. He said he walked to the hospital.

Mr Delaney was admitted. He does not remember all that much. He remembers drawing and playing table tennis. He said a few days later he noticed that his belongings had been removed. He thought they had been stolen, the staff said that he should sit down with them and talk about it. He said he noticed then that all the patients were moved out of the area, the doors were closed and Security were in place. He said he felt quite confused. Then the police showed up and said they were arresting him for his sister's murder. Mr Delaney said, "I didn't believe it, I broke down, I was distraught".

…

OPINION

I have been asked to address the following:

1. Information from clinical interview including psychiatric history, account of the alleged offence and assessment of the current mental state.

As noted above, Mr Delaney does outline a history of mental health problems that began in his late teens but because of his parents' religious beliefs it was difficult to address these issues until his early twenties when he saw a GP who started him on some antipsychotic and antidepressant medication. At that time the GP thought he might have a Bipolar Disorder and sent him to Cumberland Hospital. Mr Delaney was not very specific about the treatment received but said he had been to Cumberland Hospital a number of times where he felt quite safe and was given various medications including olanzapine. He said when he was in Western Australia he was admitted to Armadale Hospital. In Western Australia his olanzapine had been changed to paliperidone but he got "blackouts". He said when he came back to NSW he was not under any mental health care and was not taking any anti-psychotic medications.

Mr Delaney acknowledged a history of marijuana and ICE use over the last few years. He was smoking marijuana regularly and he thinks he might have had some ICE a week or two before the index offence.

He was not able to give me much information about the events in the days before the offence. He said he was very close to his sister, they got on well and they had been sharing a house for nine months. Mr Delaney said that when the offence occurred his sister had been asleep on the couch. He thought he was having an interaction with someone whom he thinks he might have met online, that this person then turned into a demon-like figure, became very tall and would not leave the house. He remembers attacking this person with some tools that he had behind the couch. He acknowledged that on that day he had been smoking marijuana. Mr Delaney then said his next memory is waking up in a hotel. He does not remember having interactions with anyone else and he said when the sun came up he took himself to Cumberland Hospital because he felt unsafe. He thought people were following him and he was hearing some voices. He has some memories of being in hospital where he did some drawing and played table tennis, then one morning he thought his possessions had been stolen, he was taken to a room by staff and asked to sit down. Security arrived, followed by the police who announced that he was charged with his sister's murder. Mr Delaney described being very distraught at that time.

…

2. Psychiatric opinion as to any diagnosis and whether the accused has available to him the full defence of mental health impairment pers s 28 of the Mental Health and Cognitive Impairment (Forensic Provisions) Act 2020 with respect to the charge of murder.

Mr Delaney does appear to have an underlying psychotic illness characterised by perceptual disturbances, ideas of reference and persecutory ideation. There also appears to be a mood component with periods of depression, anxiety and suicidal ideation. It seems these symptoms have been present since his teenage years. He has had a number of psychiatric admissions both in NSW and Western Australia.

The most likely diagnosis appears to be that of a of a Schizoaffective Disorder. He does seem to meet DSM-5 diagnostic criteria for Schizophrenia in that he appears to have had delusions, hallucinations, disorganised behaviour, there have been problems with his functioning and continuous signs seem to meet DSM-5 diagnostic criteria for Schizophrenia in that he appears to have had delusions, hallucinations, disorganised behaviour, there have been problems with his functioning and continuous signs of disturbance have been present for more than six months. He also meets diagnostic criteria for Substance Misuse involving predominantly marijuana but he acknowledges intermittent use of crystal methamphetamine. At the time of the commission of the offence it certainly is possible that he was intoxicated. The large cash withdrawals following the commission of the offence suggest he might have used this money to buy more drugs and this may have further exacerbated his underlying psychotic illness, and the psychotic symptoms that were evident after his arrest may have been a consequence of heavy drug use after the offence.

In terms of the Mental Health and Cognitive Impairment Forensic Provisions Act 2020; No. 12, Mr Delaney does seem to meet the criteria for the first three aspects of "mental health impairment" as defined in Section 4 of the Act in that:

[s. 4(1)(a)] - he has had a temporary or ongoing disturbance of thought, mood, volition, perception or memory;

[s. 4(1)(b)] - the disturbance would be regarded as significant for clinical diagnostic purposes; and

[s. 4(1)(c) - the disturbance impairs the emotional wellbeing, judgment or behaviour of the person.

130*.* I agree with Dr Martin that is difficult to be certain that his offending behaviour arose solely from either an affective disorder, including clinical depression and bipolar disorder, or a psychotic disorder [s. 4(2)(b) and (c)]. I agree it may also be related to a substance induced mental disorder that was temporary [s. 4(2)(d)].

It is possible that at the time of the commission of the offence he was acutely intoxicated as a consequence of using marijuana and crystal methamphetamine. It is also possible that drug use post offence led to further deterioration in his mental state resulting in symptoms of paranoia including auditory hallucinations, a sense that he was being followed by Freemasons and a need to change accommodation and ultimately seek refuge in hospital. These symptoms remain evident, and at this stage Mr Delaney does appear to continue to suffer from a psychotic illness that has been precipitated by substance misuse.

Jayleb Delaney spoke to the accused at around 4:00 pm on the afternoon of the offence and did not notice any unusual behaviour, although when the accused came over to Jayleb's place 20 minutes later he seemed a bit emotional.

It is worth noting that when Mr Jones picked up the accused at 8:00pm on the night of the offence, apart from being quiet he was not noticeably drug affected or displaying an unusual mental state, suggesting that any acute intoxicating effects of substances taken earlier in the day had worn off. He was noted to be quiet and did not want to sleep at home. Over the next few days he withdrew $6000 in cash, bought new clothes and was evasive on questioning about the whereabouts of his sister. There is evidence that he did smoke ICE with Jones and O'Brien on the night of 5 June 2020.

…

Having reviewed Mr Delaney, my impression is that he may not have known the nature and quality of the act [s. 28(1)(a)] and he did not know the act was wrong and was not able to reason with a moderate degree of composure [s. 28(1)b)] at the time of the commission of the offence.

However in my view it seems likely that he was acutely intoxicated by substances (marijuana and possibly crystal-methamphetamine) and this resulted in paranoia, hallucinations and aggression at the time of the offence.

137*.* Therefore in my opinion he does not have the defence of "mental health impairment" open to him.

It is of course possible he had a sudden relapse of his underlying mental illness brought on by drug use in the preceding days or weeks. However he does not seem to have been unwell in the days before the offence and significantly neither Jayleb, Jones nor O'Brien noted significantly unusual behaviour or abnormal thinking patterns in the hours after the offence.

…

I agree with Dr Martin that it is difficult to give more than a “speculative” opinion in regard to the issue of Substantial Impairment because of the underlying substance misuse issues. However, given the likelihood that he was in a self-induced state of intoxication at the time of the commission of the offence, this partial defence may not be open to him.

4. C****omment, if possible, on whether there was any causal nexus of the alleged offending conduct and the accused’s mental state and**/or diagnosis** **(**as opposed to any drug and/or alcohol intoxication) and if such a nexus exists, whether it was tr****iggered by, or was a result of, or whether their exists any relationship between the accused’s mental state and/or diagnosis and in any reported drug and/or alcohol consumption.

It certainly is possible that use of marijuana and crystal methamphetamine led to an exacerbation of Mr Delaney’s underlying psychotic illness which is well documented. However in the days before the offence there were no apparent conflicts with his sister: they were captured on CCTV shopping together. No family members of [scil. or] friends raised any concerns about his mental state.

The history suggests that drug use on the day of the offence (marijuana and possibly crystal-methamphetamine) led to psychotic symptoms and violent behaviour in the context of acute intoxication,

…

Mr Delaney certainly is well aware of the option of the NGMI illness defence and it is certainly possible that he is exaggerating symptomatology. From the documents I have reviewed and the history that I have obtained, my impression is that he had a close, loving relationship with his sister, there was no particular argument or conflict between them. The assault on her was unprovoked and out of character, and almost certainly related to substance abuse.

(emphasis added)

On 28 March 2022 the ODPP rejected the plea offer made by the applicant to manslaughter in full satisfaction of the indictment on the basis of s 23A of the Crimes Act 1900 (NSW).
Subsequently the applicant and his lawyers conferred on 6 April 2022. The notes of the conference relevantly record the following:

Confirm previous instructions to plead to murder if the negotiations are unsuccessful.

Client still concerned his mental health is being disregarded and not considered.

Advise (sic) again provided as to the defence and the way the law operates.

Report from Dr Martin again explained, and findings explained.

Report from Dr Samuels read and explained.

Both reports note that Delaney was using drugs at the time of the offence.

Advised both doctors have come to the same conclusion.

Mental health is affected by drug use.

Not sufficient to have the mental health impairment but must lead to inability to know the right and wrong of the act.

…

Client advised to read instructions to plead guilty, report from Dr Samuels, and proposed facts from the DPP.

On 10 April 2022 the applicant signed a lengthy document prepared by his lawyers instructing them to enter a plea of guilty to murder. Amongst other things, this document, which must be taken as representing the advice the applicant was given, said:

My Solicitors and Barrister have informed me that the evidence is very strong against me and there is very little chance I could be acquitted…

I understand that I was assessed by a psychiatrist, Dr Adam Martin. I have been provided with a copy of the report or had the report read to me and I accept the contents of the report. I confirm everything I said in that report was true and accurate. I understand and accept that the report was prepared to see if the defence of mental illness was available in my case. I understand accept this advice. I was advised that the defence will not be available to me as I was under the influence of illicit substances at the time of the offence. I understand and accept this advice.

As noted earlier, the plea was entered on 22 April 2022.
A letter following the sentence proceedings written by counsel for the applicant to his solicitors said this:

We subsequently obtain [sic] a report from Dr Martin and the content of that report speaks for itself. In short Lucas could not rely on any defence or reduction because of the interrelationship between schizophrenia and the likelihood of a drug induced psychosis.

Legislation

The MHCIFP Act relevantly provides:

4 Mental health impairment

(1) For the purposes of this Act, a person has a mental health impairment if -

(a) the person has a temporary or ongoing disturbance of thought, mood, volition, perception or memory, and

(b) the disturbance would be regarded as significant for clinical diagnostic purposes, and

(c) the disturbance impairs the emotional wellbeing, judgment or behaviour of the person.

(2) A mental health impairment may arise from any of the following disorders but may also arise for other reasons -

(a) an anxiety disorder,

(b) an affective disorder, including clinical depression and bipolar disorder,

(c) a psychotic disorder,

(d) a substance induced mental disorder that is not temporary.

(3) A person does not have a mental health impairment for the purposes of this Act if the person’s impairment is caused solely by -

(a) the temporary effect of ingesting a substance, or

(b) a substance use disorder.

…

28 Defence of mental health impairment or cognitive impairment

(1) A person is not criminally responsible for an offence if, at the time of carrying out the act constituting the offence, the person had a mental health impairment or a cognitive impairment, or both, that had the effect that the person -

(a) did not know the nature and quality of the act, or

(b) did not know that the act was wrong (that is, the person could not reason with a moderate degree of sense and composure about whether the act, as perceived by reasonable people, was wrong).

(2) The question of whether a defendant had a mental health impairment or a cognitive impairment, or both, that had that effect is a question of fact and is to be determined by the jury on the balance of probabilities.

(3) Until the contrary is proved, it is presumed that a defendant did not have a mental health impairment or cognitive impairment, or both, that had that effect.

(4) In this Part, act includes -

(a) an omission, and

(b) a series of acts or omissions.

Ground of appeal

Ground 1: A miscarriage of justice occurred because the applicant’s plea of guilty to murder was entered on the basis of expert opinion evidence and legal advice that was mistaken about the definition of “mental health impairment” in Section 4 of the Mental Health and Cognitive Impairment Forensic Provisions Act 2020 (NSW)

The basis of the appeal against conviction, which concerned the integrity of the plea entered by the applicant, was succinctly identified by Mr Buchen SC as follows:

A miscarriage occurred because:

(a) The expert opinion did not address the material question posed by the relevant statute which is whether drug intoxication was the sole cause of the mental health impairment;

(b) That the legal advice then given to the applicant was necessarily and consequentially flawed; and

The further evidence

The applicant sought to read an affidavit of his solicitor which annexed emails passing between his solicitors at trial and the ODPP, file notes of conferences held between the applicant and his legal advisers prior to the entry of the plea, the letter of instructions to Dr Adam Martin and a report from Dr Olav Nielssen dated 22 February 2024 providing an opinion about whether the applicant had available to him the defence under s 28 of the MHCIFP Act.
The Crown did not object to the material annexed to the solicitor’s affidavit except in relation to the report of Dr Nielssen on the basis of what was said by this Court in Xie v R [2021] NSWCCA 1; (2021) 386 ALR 371 at [436]-[439]. Ultimately, the applicant did not press for the admissibility of the report of Dr Nielssen and the Court rejected that report.
The appellant in Xie sought to adduce further evidence at the hearing of his appeal against his conviction for five counts of murder. The Court discussed the distinction between a consideration of evidence that is said either to be new or fresh on the one hand and evidence to demonstrate that a trial departed from the essential requirements of the criminal process. The Court (Bathurst CJ, R A Hulme and Beech-Jones JJ) said:

[436] In those submissions, the appellant sought to identify two classes of cases in which further evidence was received with the first being the receipt of “fresh” or “new” evidence. The second class was said to be typified by the decision of this Court in Cesan v DPP (Cth) [2007] NSWCCA 273; (2007) A Crim R 385 (“Cesan”) where evidence was sought to be tendered as to the conduct of a trial judge in falling asleep during part of a trial and the medical condition that caused that to occur (at [21] to [22]). Evidence of the former was objected to by the respondent on the basis that it was neither fresh nor new evidence. Basten JA dissented on the outcome in this Court but that outcome was reversed in the High Court (Cesan v The Queen (2008) 236 CLR 358; [2008] HCA 52). For present purposes, it suffices to note the following analysis by his Honour of the basis for the receipt of that evidence by this Court which appears to have been accepted by the other members of the Court (at [178] per Grove J and at [216] per Howie J):

“24 The language of s 12(1) [of the Criminal Appeal Act] is curious in some respects, but it was not suggested that the Court did not have power to take the evidence tendered in the present case. Rather, it was said that in accordance with well-established discretionary principles, the Court should only accept the evidence if it could properly be regarded as fresh evidence, that is evidence which was not available at the time of trial and could not with reasonable diligence have been obtained at that time. The Director also argued that the evidence was irrelevant to the case sought to be presented, which at that stage relied on principles analogous to those underlying apprehended bias. As will appear below, the evidence called by the Appellants was relevant to the case as the argument was developed, within the terms of s 55 of the Evidence Act 1995 (NSW).

25 As explained by Barwick CJ in Ratten v The Queen (1974) 131 CLR 510 at 518-520, the manner in which evidence should be considered on a criminal appeal will depend significantly on the issue sought to be raised. For example, as his Honour noted at p 520:

‘To sum up, if the new material, whether or not it is fresh evidence, convinces the court upon its own view of that material that there has been a miscarriage in the sense that a verdict of guilty could not be allowed to stand, the verdict will be quashed without more. But if the new material does not so convince the court, and the only basis put forward for a new trial is the production of new material, no miscarriage will be found if that new material is not fresh evidence.’

26 Quite different considerations arise where the new material is put forward*, not in contradiction of the jury’s verdict*, or as inconsistent with the evidence called below, but to demonstrate that for some reason the trial departed from the essential requirements of the criminal process, or was in some other respect procedurally unfair. In some cases, the basis of a complaint may be apparent from the transcript. In other cases that will not be so and in those cases the Court should be slow to exclude evidence which would provide the only proper basis upon which the legitimacy of the challenge could be assessed. In the absence of binding authority to the contrary (and no authority was relied upon) the Court was satisfied that the evidence should be admitted.” (emphasis added)

[437] This extract confirms that the power conferred by s 12(1) of the Criminal Appeal Act to, inter alia, receive further evidence “if it thinks it necessary or expedient in the interests of justice” to do so is not a free standing power to receive evidence, but one which must be exercised having regard to the particular ground of appeal (which in turn will reflect one of the three limbs of s 6(1)). The “interests of justice” in this context are a reference to properly determining the relevant ground of appeal according to law.

[438] Thus, if what is sought to be done is, to use Basten JA’s phrase, “contradict … the jury’s verdict”, that is contend that there was other evidence not adduced at the trial that undermined the Crown case or pointed to the innocence of the accused, then the rules concerning fresh and new evidence are engaged. In this case, to the extent that any of the additional evidence was sought to be deployed on appeal in support of Grounds 1 to 3 then it was only being done for the purpose of attempting to relitigate so much of the 2016 trial that concerned the admission and treatment of DNA evidence concerning Stain 91. Hence to the extent that evidence is sought be adduced on appeal in support of those grounds, then its admission is governed by the rules pertaining to fresh or new evidence.

[439] However, the above discussion in relation to Ground 8 suggests that there is scope for the reception of evidence on appeal that is not necessarily fresh or new but which may establish what the position of counsel was when they committed the relevant act or omission said to have caused a miscarriage of justice or which may tend to establish what the effect of that act or omission was on the trial process. It is not necessary to explore the limits of those possibilities on this appeal.

It was initially submitted by the applicant that Dr Nielssen's report was admissible to address what would have ensued had trial counsel taken the step that the applicant submitted should have been taken. Reliance was placed on what was said in R**E v R [2024] NSWCCA 180.
The position in RE was somewhat different from the position in the present case. An important issue in that case related to the timestamps on Instagram messages and whether they were consistent with the times recorded on call charge records. It was an issue whether Instagram messages were being sent by the complainant at a time when the accused was on a telephone call. The evidence sought to be adduced at the hearing of the appeal was whether the call charge records and the Instagram timestamps operated on the same timing system. An expert report was obtained to answer that question and was sought to be tendered at the hearing of the appeal.
It was in those circumstances that Mitchelmore JA said at [98]:

… The effect of the objective evidence was explained by Mr Ghosh and Mr Campey [the experts], and if such a report had been obtained, it could have been put before to the jury. However, for the reasons I have already explained, in light of the Agreed Facts, it was not essential. Consistently with the reasoning in Xie at [441], I would admit the new evidence on the basis that it addressed what would have ensued had trial counsel taken the step that the appellant submitted he should have taken, subject to a limitation on its use to this ground pursuant to s 136 of the Evidence Act. However, I do not consider that its absence evidenced a failure on the part of the appellant’s trial counsel in the manner alleged.

In the present matter, not only did Dr Nielssen's report go beyond showing what evidence might have been given at the trial, it expressed an opinion that the applicant made out the defence under s 28 of the MHCIFP Act. The applicant accepted that the latter opinion was not admissible.
Dr Nielssen's opinion about what the proper approach to an assessment of whether the s 28 defence was made out is not necessary in the present case. The matter can be determined by an examination of the reports of Dr Martin and Dr Samuels and of the legal advice provided by the solicitors on the basis of those reports. The test that ought to have been applied under s 28 is one for the Court to determine. The approach another expert such as Dr Nielssen would have taken is not relevant.

Submissions

The applicant submitted that both the psychiatrists provided their opinions on the basis that the applicant did not have a mental health impairment at the time of the offence because he was intoxicated. The applicant submitted that Dr Martin asked himself the wrong question by addressing whether the issue of acute intoxication with methylamphetamine could not be excluded as the most important factor being relevant to the alleged offending. The applicant submitted that neither expert considered whether intoxication was the sole cause of the applicant's impairment as provided by s 4(3) of the MHCIFP Act, or whether it was reasonably possible that the applicant's schizophrenia also contributed to his mental state at the time.
The applicant submitted that the mistake was repeated in the legal advice given to the applicant in accordance with the expert opinion. In effect, the applicant was advised that he did not have a mental illness defence because he was intoxicated at the time of the offence.
The applicant submitted that it appears likely that, if the experts had been required to consider whether the applicant’s intoxication by marijuana and/or ice at the time of the offence was the sole cause of his impaired state, they would have concluded it was reasonably possible it was not, given the applicant's long-standing mental health problems.
The Crown submitted that the opinions expressed by the psychiatrists in their reports were not mistaken about the definition of “mental health impairment”. Although they did not use the word “solely” in their reports, it was apparent that after careful consideration each of the psychiatrists considered that intoxication provide the explanation of the applicant's behaviour.
The Crown drew attention to the conclusions of Dr Martin in paras 37 and 38 of his report that the physical act appeared to have been most likely in the context of acute drug use, that it was not possible to state that the applicant did not know the nature and quality of his act or that it was wrong as a result of a mental health impairment as opposed to the effect of acute intoxication, that the offending appeared to have occurred in direct nexus to the effects of drug addiction affecting the applicant's level of control and judgment, and that the applicant's mental state at the material time could be assumed to have been the end product of drug addiction and intoxication affecting his thought processes and impairing his ability to behave rationally.
The Crown submitted that while Dr Martin noted that the applicant had a serious mental health impairment, it does not follow that he considered that condition contributed to the applicant's mental state at the time of the offence. His opinion, that it would be speculative to argue that the applicant was significantly impaired by chronic mental illness to the extent that he would not have been able to appreciate the wrongfulness of his behaviour or had been able to reason with moderate composure, does not imply that he opined that “it was speculative that it was one or the other” (namely mental health impairment or acute intoxication) as the applicant submitted.

Consideration

In Layt v R [2020] NSWCCA 231, Payne JA (Walton and Fullerton JJ agreeing) summarised the principles relating to conviction appeals following a plea of guilty as follows:

[24] Where an applicant has entered a plea of guilty and subsequently seeks to appeal against conviction, it is not necessary to conduct an examination into the applicant’s guilt or innocence. Rather, the relevant inquiry is into the integrity of the plea of guilty: Sabapathy v R [2008] NSWCCA 82 at [14]; Thafer v R [2019] NSWCCA 143 at [287].

[25] When a person enters a plea of guilty, that person admits to all of the elements of the offence (at least to the minimum level necessary for a conviction) and the conviction will not be set aside unless it can be shown that a miscarriage of justice has occurred: R v Chiron [1980] 1 NSWLR 218.

[26] The rarity with which this Court grants leave to withdraw the plea of guilty at trial is an aspect of the public interest in the finality of proceedings: Reg. v O’Neill [1979] 2 NSWLR 582.

[27] While the categories are not closed, some examples of where leave to withdraw a plea of guilty has been granted are:

the nature of the charge to which the plea has been entered is not appreciated: R v Ferrer-Esis (1991) 55 A Crim R 231 at 233;

the plea is not “a free and voluntary confession”: R v Chiron at 220;

the “plea [is] not really attributable to a genuine consciousness of guilt”: R v Murphy [1965] VR 187 at 191;

there has been a “mistake or other circumstances affecting the integrity of the plea as an admission of guilt”: Sagiv v R (1986) 22 A Crim R 73 at 80;

the plea has been “induced by threats or other impropriety” and the appellant would not otherwise have pleaded guilty: R v Cincotta (Court of Criminal Appeal (NSW), 1 November 1995, unrep); and

the plea is not unequivocal or is made in circumstances suggesting it is not a true admission of guilt (Maxwell v The Queen (1996) 184 CLR 501 at 511; [1996] HCA 46).

[28] It is for the person seeking to withdraw the plea of guilty to satisfy the Court that leave to withdraw the plea should be granted: R v Boag (1994) 73 A Crim R 35; R v Ferrer-Esis. It is only where the material before the Court discloses a real question about the guilt of an accused that the Court will grant leave to withdraw the plea: R v Toro-Martinez [2000] NSWCCA 216; (2000) 114 A Crim R 533.

In White v R (2022) 110 NSWLR 163; [2022] NSWCCA 241, this Court confirmed that when an application is made to withdraw a plea of guilt after conviction and sentence, the conviction can only be set aside if it is established that a miscarriage of justice has occurred in accordance with s 6(1) of the Criminal Appeal Act 1912 (NSW).
In Sagiv v R (1986) 22 A Crim R 73, Lee J (with whom McInerney and Campbell JJ agreed) said at [80]:

It is clear that in the case of mistake or other circumstances affecting the integrity of the plea as an admission of guilt the court should readily grant leave [to withdraw the plea].

In the present case the evidence shows clearly that the plea to murder was entered on the basis of the advice given by the applicant's solicitors. That advice was in turn based on what appeared in the reports of Dr Martin and, to some extent, of Dr Samuels. If wrong advice was given, it must be ascertained if it affected the integrity of the plea. Senior counsel for the applicant made clear, in response to a question from the Court, that any ground of appeal alleging incompetence on the part of the lawyers did not add anything to the appeal if miscarriage was established and, hence, no such ground was raised. That must be correct, because the enquiry is not whether the lawyers were incompetent in giving the advice; rather, the enquiry is whether, if the advice was wrong, it affected the integrity of the plea and thus constituted a miscarriage of justice: TKWJ v The Queen (2002) 212 CLR 124; [2002] HCA 46 at [31], [79] and [97].
Sections 4 and 28 of the MHCIFP Act have clarified in statutory form what had been decided on common law principles, at least by this Court’s decision in Fang v R (2018) 97 NSWLR 876; [2018] NSWCCA 210. What s 4 has done is to identify in the first place in sub-s (1) what constitutes a mental health impairment, to give in sub-s (2) what Button J in R v Murray [2024] NSWSC 503 at [51] described as “illuminative examples”, and then in sub-s (3) to make clear that a person does not have a mental health impairment if it was “caused solely by" either the temporary effect of ingesting a substance or a substance use disorder.
The definition overcomes, therefore, some of the difficulties identified in a number of the cases referred to in Fang. Indeed, what now appears in s 4 might be thought to have been succinctly expressed by Powell JA (Studdert and Levine JJ agreeing) in R v De Souza (1997) 41 NSWLR 656 where he said that “disease” in the context of s 23A of the Crimes Act 1900 (NSW):

Exclude(s) effects which are more or less transitory, or are due to a temporary malfunction…or are self-induced, as, for example, as the result of the consumption of alcohol or the use of drugs.

Section 4(3) in particular removes the difficulty in cases where an accused had a pre-existing mental illness but the underlying mental illness was triggered or exacerbated by the use of alcohol or drugs: cf Fang at [56] and the decisions identified in that paragraph. Under s 4(3) a person does not have a mental health impairment for the purposes of the MHCIFP Act if the impairment is caused solely by drugs and/or alcohol, or a substance use disorder. As Dhanji J made clear in R v Patterson (No 6) [2024] NSWSC 458 at [16], the “caused solely by” test cannot be equated with a “but for” test where it would be sufficient to prove that but for the ingestion of drugs the psychosis would not have occurred.
Both Dr Martin and Dr Samuels considered that the applicant suffered from a mental health impairment being schizophrenia. However, what both doctors struggled with was the fact that on top of the mental health impairment of schizophrenia they considered that the applicant was acutely intoxicated by substances at the time of the killing. Their difficulty appeared to be attributing cause or contribution to one or both of those matters. Dr Martin approached the matter at para 57 of his report by noting that acute intoxication with methylamphetamine could not be excluded. That was not, however, to engage with the test in s 4(3). It was not a question of not being able to exclude the drug ingestion but, rather, whether that was the sole cause of the impairment. Both doctors concluded that as a result of the acute intoxication the applicant did not have available the mental health impairment. That led each to the conclusion that the applicant did not fall within s 28 of the MHCIFP Act, despite s 4(3) excluding an accused, who otherwise had a mental health impairment, only in the circumstances where the impairment was caused solely by the use of the drugs.
The Crown submitted that although Dr Samuels did not say in terms that the applicant’s impairment was caused solely by the temporary ingestion of a substance, that was the effect of his opinion as set out in paras 130 to 143 of his report. In my opinion, such a conclusion cannot be derived from Dr Samuels’ report. His only reference to “solely” in his report is in para 130 where he agrees with Dr Martin that it was difficult to be certain that the applicant’s behaviour “arose solely from” an affective disorder or a psychotic disorder. That was to reverse the enquiry. Section 4 is not concerned with finding that the offending behaviour arose solely from a particular disorder; it is concerned in sub-s (3) with excluding the impairment if it was caused solely by (in this case) the temporary ingesting of a substance.
The remaining paragraphs in Dr Samuels’ report relied on by the Crown, to the extent that they throw light on this central issue, are focused on the applicant’s ingestion of the drugs which leads to Dr Samuels’ conclusion at para 137 that “therefore” the applicant does not have the defence of mental health impairment. He does acknowledge at paras 138 and 144 that it was possible that the applicant had a relapse or an exacerbation of his underlying mental illness brought on by the drug use, but he then fails to address the test in s 4(3) in respect of that possibility.

[58] As I have already indicated on my construction of s 4, s 4(3) creates an exception to the circumstances in which a person would have a mental health impairment even though the matters referred to in ss 4(1) and (2) would be satisfied. That is, I do not read s 4(2) and s 4(3) as being mutually exclusive provisions.

[59] It is the Crown who asserts that the exception is enlivened. Whilst for the purposes of s 28 the obligation may be on the accused to rebut the presumption arising in s 28(3), I do not consider that in the context of the criminal law and the purposes of the MHCIFP Act that the onus rests on the accused to establish something that he does not assert but that which is asserted by the Crown.

…

[61] In my view, as it is the Crown who asserts that the facts required for the operation of s 4(3) are present, it is the Crown who bears the onus of establishing those facts for the purposes of the application of s 4(3).

[62] The accused must establish the matters referred to in ss 4(1)(a), (b) and (c) and that his mental health impairment arises out any of the disorders (or for other reasons) as set out in s 4(2). However, it is for the Crown to establish on the balance of probabilities that despite any satisfaction in respect of ss 4(1) and (2), the accused's mental health impairment was caused solely by one of the matters referred to in ss 4(3)(a) or (b).

Subsequently, in R v Sheridan [2022] NSWSC 1669 a similar question arose where an accused sought to demonstrate that he had a mental health impairment, but the psychiatrist instructed by the Crown considered that the impairment was caused solely by the temporary effect of the accused's drugtaking. Garling J was referred to Miller and his Honour said that for reasons of judicial comity he would ordinarily follow a decision of another judge of the Court unless he was convinced that it was plainly wrong. His Honour said that he was not so convinced, and went on to say:

[22] As the statute makes explicit, the onus is on an accused to establish the defence of mental health impairment under s 28 of the Act. The provisions of s 4(1) describe what a mental health impairment is. The provisions of s 4(3) provide for an exception or an exclusion to the existence of a mental health impairment, namely when a person’s mental health impairment is not of a kind which can be included within the definition and, accordingly, not available to be relied upon as a defence.

The determinations in Miller and Sheridan were followed in R v Patterson (No 6*)* [2024] NSWSC 458, although without any resistance by the Crown to the obligation placed on it under s 4(3) as determined in those cases.
Finally, the issue was considered in advance of the trial commencing in R v Murray [2024] NSWSC 503. The Crown again sought to argue that Miller, Sheridan and Patterson (No 6) were wrongly decided. Button J took the same course as that taken by Garling J in holding that there were no compelling reasons not to follow the earlier decisions. Nevertheless, his Honour considered that what he described as the “carveout” in s 4(3) might be considered an alteration to the defence at common law, because the accused bore the onus on the balance of probabilities with regard to all aspects of the defence (at [21]), and he suggested that the question of onus relating to the carveout in s 4(3) was contestable (at [62]).
Although the Crown argues that it is the entirety of s 4 which provides the definition of mental health impairment with the result that sub-s (3) is not to be regarded as an exception, that submission does not take account of the requirement, on that construction of s 4, that the accused would at the outset have to prove that his impairment was not caused solely by both of the matters set out in s 4(3)(a) and (b). This is where the Act has arguably brought about a change to the common law position.
In R v Radford (1985) 42 SASR 266, King CJ said at 274:

The expression ‘disease of the mind’ is synonymous, in my opinion, with ‘mental illness’ … I do not think that a temporary disorder or disturbance of an otherwise healthy mind caused by external factors can properly be regarded as disease of the mind as that expression is used in the M’Naghten rules. As Lord Denning pointed out in Bratty v Attorney*‐*General (Northern Ireland) [[1963] AC 386 at 412] … any ‘mental disorder which has manifested itself in violence and is prone to recur is a disease of the mind’.

That statement was endorsed as correct by Mason CJ, Brennan and McHugh JJ in R v Falconer (1990) 171 CLR 30; [1990] HCA 49 at 53.

In that way, a temporary disorder or disturbance, so described, would not constitute a disease of the mind to bring the M’Naghten rules into consideration. By contrast, such a condition might satisfy s 4(1). To exclude it, it must be a condition which falls within s 4(3).
Accordingly, in my opinion, s 4(3) provides an exception or a qualification to what is contained in s 4(1).
In Dowling v Bowie (1952) 86 CLR 136, Dixon CJ (Fullagar and Kitto JJ agreeing) said at 139:

The argument treats the case as governed by the common law doctrine that where a statute having defined the grounds of some liability it imposes proceeds to introduce by some distinct provision a matter of exception or excuse, it lies upon the party seeking to avail himself of the exception or excuse to prove the facts which bring his case within it. The common law rule distinguishes between such a statutory provision and one where the definition of the grounds of liability contains within itself the statement of the exception or qualification, and in the latter case the law places upon the party asserting that the liability has been incurred the burden of negativing the existence of facts bringing the case within the exception or qualification. See Barritt v Baker. The distinction has been criticized as unreal and illusory and as at best, depending on nothing but the form in which legislation may be cast and not, upon its substantial meaning or effect. The question, however, where in such cases the burden of proof lies may be determined in accordance with common law principle upon consideration of substance and not of form. A qualification or exception to a general principle of liability may express an exculpation, excuse or justification or ground of defeasance which assumes the existence of the facts upon which the general rule of liability is based and depends on additional facts of a special kind. If that is the effect of the statutory provisions, considerations of substance may warrant the conclusion that the party relying on the qualification or exception must show that he comes within it: Cf. Pye v. Metropolitan Coal Co. Ltd.; Dar**ling Island Stevedoring & L**ighterage Co. Ltd. v. Jacobson.

In Waters and Others v Mercedes Holdings Pty Ltd and Others [2012] FCAFC 80; (2012) 289 ALR 489, the Full Court of the Federal Court said:

[16] The general principles to be applied when considering a statutory provision which imposes an obligation subject to a qualification have been explained by the High Court on a number of occasions. McHugh J in Avel Pty Ltd v Multicoin Amusements Pty Ltd (1990) 171 CLR 88 at 119; 97 ALR 19 at 41; 18 IPR 443 at 465 summarised these principles as follows:

When a statute imposes an obligation which is the subject of a qualification, exception or proviso, the burden of proof concerning that qualification, exception or proviso depends on whether it is part of the total statement of the obligation. If it is, the onus rests on the party alleging a breach of the obligation. If, however, the qualification, exception or proviso provides an excuse or justification for not complying with the obligation, the onus of proof lies on the party alleging that he falls within the qualification, excuse or proviso: Vines v Djordjevitch [(1955) 91 CLR 512 at 519–20; [1955] ALR 431 at 433–4]. Whatever form the statute takes, the question has to be determined as one of substance: …

The reference to Vines v Djordjevitch (1955) 91 CLR 512 at 519–20; [1955] ALR 431 at 433–4 (Vines) was a reference to the following observations of Dixon CJ, McTiernan, Webb, Fullagar and Kitto JJ:

But whether the form is that of a proviso or of an exception, the intrinsic character of the provision that the proviso makes and its real effect cannot be put out of consideration in determining where the burden of proof lies. When an enactment is stating the grounds of some liability that it is imposing or the conditions giving rise to some right that it is creating, it is possible that in defining the elements forming the title to the right or the basis of the liability the provision may rely upon qualifications exceptions or provisos and it may employ negative as well as positive expressions. Yet it may be sufficiently clear that the whole amounts to a statement of the complete factual situation which must be found to exist before anybody obtains a right or incurs a liability under the provision. In other words it may embody the principle which the legislature seeks to apply generally. On the other hand it may be the purpose of the enactment to lay down some principle of liability which it means to apply generally and then to provide for some special grounds of excuse, justification or exculpation depending upon new or additional facts. In the same way where conditions of general application giving rise to a right are laid down, additional facts of a special nature may be made a ground for defeating or excluding the right. For such a purpose the use of a proviso is natural. But in whatever form the enactment is cast, if it expresses an exculpation, justification, excuse, ground of defeasance or exclusion which assumes the existence of the general or primary grounds from which the liability or right arises but denies the right or liability in a particular case by reason of additional or special facts, then it is evident that such an enactment supplies considerations of substance for placing the burden of proof on the party seeking to rely upon the additional or special matter: …

What is clear from both of these decisions is that the question of statutory construction is to be resolved as a matter of substance rather than as a matter of form. …

(emphasis added)

Applying that principle to the construction of s 4 of the MHCIFP Act does not impugn any principle associated with onus and burden of proof in the criminal law. The accused has the burden of demonstrating that he falls within s 28(1) of the MHCIFP Act if he asserts that he falls within it. So much is clear from s 28(3). The effect of that is that the applicant must bear the onus of proof in relation to s 4(1).
The Crown correctly points out that s 4 is a definition that not only plays an important role in the s 28 defence, but also provides the basis for diversionary orders in the Local Court under s 14 of the MHCIFP Act and it is a definition relevant to the question of fitness under s 36 of that Act. The Crown also correctly points out that it is not always the accused who seeks to invoke s 4. Support for that submission may be found in Falconer at 62-63.
It is not clear, however, why those matters have any bearing on considerations of the onus of proof within s 4. Every consideration of whether an accused has a mental health impairment will not engage the matters in sub-s (3). For example, in R v Jawid [2022] NSWSC 788 the Crown at a judge alone trial asserted that the accused had a mental health impairment under s 28 of the MHCIFP Act with the result that a special verdict ought to be given. On the other hand, the accused contended that he merely had a defence of substantial impairment under s 23A of the Crimes Act. In that case, the Crown had the onus of establishing that the accused had a mental health impairment which should result in a special verdict. No issue arose under sub-s (3).
The question of who bears the onus of proof under sub-s (3) only arises if an issue is raised suggesting that the accused's impairment is caused solely by the matters in that sub-section. If the accused asserts only that he suffers from a mental health impairment and the Crown seeks to show that the accused does not have a mental health impairment for the purposes of the Act (whether s 28 or otherwise) then the onus of proof is on the Crown to prove the exception that it has raised. The analysis by Cavanagh J in Miller is correct. In that regard, the directions provided by Dhanji J in Patterson (No 6*)* should be accepted as the preferred directions in circumstances where an accused relies on a mental health impairment and the Crown relies on sub-s (3).
There is no onus on the accused under sub-s (3) even in circumstances where on his own case, a substance or a substance use disorder is raised by the evidence. That is because unless it is shown that the impairment was caused solely by the ingesting of the substance or the substance use disorder, the accused will not be precluded from relying on a mental health impairment.

Conclusion

I would propose the following orders:
Extend time for the filing of the Notice of Appeal to 28 November 2024.
Grant leave to appeal.
Uphold the appeal.
Quash the conviction.
Grant leave to the appellant to withdraw his plea of guilty to the murder of Gabriella Delaney.
Remit the matter to the Supreme Court for retrial.
Stand into the Arraignments List in the Supreme Court on 4 July 2025.
WEINSTEIN J: I agree with Davies J.

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Delaney v R

At a glance

Court

Decision date

Before

Catchwords

Source

Catchwords

Judgment

HEADNOTE

Judgment

The Offending

Psychiatric Reports

Legislation

Ground of appeal

The further evidence

Submissions

Consideration

Conclusion

Parties

Legislation Cited (8)

Cases Cited (14)

Cited By (2)