Substantial impairment
52The partial defence of substantial impairment by abnormality of mind is established by the provisions of s 23A Crimes Act 1900. To make good to the defence it is necessary for the accused to prove that it is more likely than not that:
(a)At the time he bludgeoned Mr Makaradi the accused's capacity to understand events, or to judge whether his actions were right or wrong, or to control himself was substantially impaired by an abnormality of mind arising from a pre-existing mental or physiological condition; and
(b)The impairment was so substantial as to warrant liability for murder being reduced to manslaughter.
Both matters must be established by the accused. The first element is a mere question of fact to be decided on all of the evidence including the expert opinion of the qualified psychiatrists and clinical neuropsychologists. The second aspect requires me to make a value judgment. It is not permissible for me to defer to the opinions of experts, rather the second question must be determined by the application of the standards of ordinary, well-informed members of the community. Moreover, in deciding the second question, I am to disregard the effects of any self-induced intoxication.
53In the context of the first question, substantial means more than trivial; real, not fanciful; of substance.
54I also record for the purpose of this defence that I am satisfied on the balance of probabilities that Mr Makaradi probably hit the accused, before the accused attacked him. In arriving at this conclusion I have borne in mind what I said at [22] about out of court statements of the accused, and their potential unreliability. But I also bear in mind the disadvantage that the accused suffers having regard to his mental disability, including his difficulty in making a rational decision about whether or not to give evidence. I have heard evidence that his intellectual disability does not preclude him from lying if it suited him. Reconsidering the evidence in the light of these considerations, I remain of the view that Mr Makaradi probably "started it" by punching the accused and telling him he was leaving. The first three people the accused saw were Mr Hannan and the two Ms Matas. He told each of them that Mr Makaradi hit or punched him. In the telling, he did not hide that he had beaten Mr Makaradi with his bat. In addition to the evidence I have recounted at [40] and [41], the accused told Dr Stark, the Director of Clinical Forensic Medicine for the New South Wales police that Mr Makaradi punched him in the face (106.25T). As I have said that examination took place on 31st May. The point is, that from the earliest accounts given by him, and throughout, the accused has consistently said that Mr Makaradi hit him first. Notwithstanding his ability to confabulate, the consistency of the story in one who suffers from his difficulties is to my mind a telling point.
55Further, the contextual or relationship evidence provided by Ms Wilson, Mr Birks, Mr Sells and Mr Reeves makes it likely that such an event could have occurred. And I am satisfied that it did.
56The psychiatrists, Dr Allnutt, and Dr Furst, and the clinical neuropsychologists, Dr Hepner and Dr Pulman all agree, from their different standpoints, that Mr Peterson has an underlying condition. Dr Allnutt, in his in his report of 23rd February 2014 described the accused as suffering from an intellectual disability on the lower end of the mild range possibly in the moderate range. He said that as a consequence of his mental disability he has "an abnormality of mind" that impaired executive functioning and produced difficulties with speed of thought processing, inflexibility of thinking, problems with attention, and working memory.
57In oral testimony he said (at 48.49T):
I believe he had an abnormality of mind arising out of an underlying condition. That underlying condition being a combination of two things, intellectual disability, which is a developmental lifelong condition and executive dysfunction caused by frontal lobe damage which was in my view more recent.
He understood the neuropsychological evidence to be consistent with that diagnosis. It should also be added that the accused has a long history of epilepsy which is unmedicated. He has frequent seizures which may be related to the frontal lobe damage. Dr Allnutt said seizures could cause brief periods of a lack of oxygen which could cause brain damage (49.15T).
58Dr Furst's opinion was similar (Exhibit 2 page 8). Dr Furst also said, in his oral testimony at (125.15T), that the underlying condition was the combination of the intellectual disability and a broader cognitive impairment resulting from the frontal lobe damage.
59Dr Pulman, a clinical neuropsychologist, in her report of 10th June 2014 (Exhibit H page 7-8), explained that epilepsy was more prominent in persons suffering intellectual disability although the relationship between the two "is not always clear". Clinical studies of adults with intellectual disability who had epilepsy demonstrate that they have higher rates of behavioural and psychological problems than those without epilepsy. Persons suffering intellectual disability and epilepsy "were also significantly more likely to have severe or fleeting behavioural problems, with mood swings being most prominent". I accept this evidence. From her testing she described Mr Peterson's level of intellectual functioning as falling in the extremely low range, below 99.8 percent "of his same aged peers". I am also persuaded that the accused's abnormality of the mind resulting from his underlying condition resulted in the substantial impairment of his capacity to understand events and control himself at the time he bludgeoned Mr Makaradi. Probably he had the capacity for moral judgment, after all, he told the younger Ms Mata he had "done something wrong".
60Dr Allnutt and Dr Furst disagreed somewhat about the significance of the impairment of his ability to understand events. Dr Allnutt accepted that impairment, but thought he could understand the nature of the events as they unfolded on 30th or 31st May 2012. On the other hand, Dr Furst (at 126.20T) said because of the severity of his intellectual disability and frontal lobe impairment it would be "difficult for him to understand or appreciate the consequences of his actions as in, for example in this case, whether hitting the victim as alleged would lead to the very serious injuries that occurred"(my emphasis).
61Having regard to the severity of the intellectual disability, as described by Dr Pulman and Dr Hepner, and the long history of behavioural problems including problems with aggression summarised in Exhibit 5, I prefer that part of the evidence of Dr Furst to that part of the evidence of Dr Allnutt. Dr Allnutt did not really address the issue of the accused's appreciation of the consequences of his actions.
62In terms of loss of self-control, no one described the nature of the accused's problems better than Dr Allnutt. Dr Allnutt accepted that the impairment in self-control was substantial, if that word was defined as "more than trivial and of substance" (54.15T). He gave the following metaphor in oral evidence (55.10T):
Like all of us we are prone to react at one point in anger to a certain situation and at one point in time it may not at another, so you've got to bear that in mind. If I could put it this way is that as a consequence of his frontal lobe damage his ability to inhibit a strong emotional response was compromised. So in simple terms his brake pads were eroded so he had more difficulty to put on the brakes than you and I might have and that difficulty was probably also compounded by his disability but not necessarily.
He went on to say (55.20T):
In his case if we said that he felt anger by what he perceived as something that was an affront to him and then erupted with rage, his ability to inhibit that was diminished by virtue of his executive dysfunctional frontal lobe damage more than trivially.
I accept this evidence.
63This leaves the second question. Before answering it, I think it worth considering the evidence in relation to intoxication as I am required to disregard the effects of self-induced intoxication on his impairment when deciding the second question.
64It seems to me that it is for the accused to satisfy me on the balance of probabilities either that he was not intoxicated in the relevant sense, or if he, was what effect that had on his impairment. There is no doubt that Mr Makaradi was very intoxicated. His blood alcohol reading was 0.277. The accused told Dr Stark (Exhibit B [4.5]) that he and Mr Makaradi "had shared most of a standard bottle of whiskey with coke" on the night Mr Makaradi was killed. Some alcohol had been left in the bottle. Blood tests taken later on 31st May 2012 from the accused were negative for alcohol but positive for cannabinoids. Nothing in Dr Stark's written or oral evidence suggested that she noticed anything of the after effects of severe intoxication on the part of the accused. So far as the cannabinoids were concerned, Dr Duflou said that the pathology results demonstrated that the accused had used cannabis "in the prior week to weeks" (119.7T). I infer that cannabis is metabolised at a much slower rate than alcohol. From this evidence I would not infer that he was intoxicated by cannabis at the time he killed Mr Makaradi.
65The accused told Dr Allnutt that prior to striking Mr Makaradi he had consumed "about 4 cups of whiskey and coke". Dr Pulman received a history that Mr Makaradi had shown up with a bottle of whiskey but received no history of how much the accused had consumed. The accused told Dr Allnutt that he had been drinking with Mr Makaradi between about 10 pm and midnight and estimated he had drunk about 4 to 5 whiskeys and coke and did not feel intoxicated. The accused said Mr Makaradi was drinking the whiskey straight and he also explained that he was concerned about Mr Makaradi leaving to go home because Mr Makaradi was drunk.
66From this evidence, although I am satisfied that the accused had taken some alcohol, the quantity involved is not so great as to have any significant effect on his substantial impairment due to the abnormality of mind caused by his underlying condition.
67Dr Allnutt said that the impairment in terms of his capacity to control himself was substantial, independent of intoxication by substances, "alcohol or otherwise" (68.25T).
68Dr Furst said that he assumed the ingestion of alcohol made no difference at all to his opinion about the accused suffering from substantial impairment because (128.35T):
... the intellectual disability he suffers from and the epilepsy are both longstanding conditions present from early life, irrespective of alcohol intoxication. ... [the] neuropsychological testing conducted after his arrest was in the absence of alcohol, and both tests by Dr Hepner and Susan Pulman revealed the global impairment which I relied on to form my opinion.
69I am satisfied that a degree of intoxication by alcohol would not have added materially to the accused's impairment, or the seriousness of it, at the time of his assault on Mr Makaradi.
70I remind myself that the second question is whether the accused's impairment was so substantial as to warrant liability for murder being reduced to manslaughter. Counsel were divided about the nature of the inquiry. Learned Queens Counsel for the Crown argued that the focus was on the expression "so substantial". The question was about the magnitude, or perhaps seriousness, of the impairment of the mental capacity of the accused. Mr Smith argued that the second question was a single expression of a composite idea. The seriousness of the impairment was clearly relevant but a broader inquiry was called for. Both counsel relied on the analysis of Johnson J in Potts v R [2012] NSWCCA 229 at [33] and the authorities his Honour considered.
71Omitting citations Justice Johnson said:
It has been said that the issue under s 23A(1)(b) is a task for the tribunal of fact, which must approach that task in a broad commonsense way, involving a value judgment by the jury representing the community, and not a finding of medical fact:. It is often put to juries ... that an impairment is substantial if it is such as warrants the reduction of the crime from murder to manslaughter: .. In R v Majdalawi, Adams J observed... that the "value judgment by the jury representing the community" to which Hunt CJ at CL referred in R v Ryan "is a decision about culpability" and hence "is not a medical question".
I observe that to warrant the reduction in legal liability it is not enough that the impairment is substantial, something more is required. The impairment must be "so substantial" before the reduction is warranted. Another way of putting this may be that the impairment is substantial enough to warrant the reduction.
72This statutory language makes it natural to consider the seriousness of the impairment of the accused's mental capacity. But as the second question is not a medical question, that consideration cannot be of decisive importance. The question is about whether legal responsibility for the most serious crime of murder should be attributed to the accused. Seriousness of his condition is of central but not necessarily decisive importance.
73As the inquiry relates to the appropriate level of culpability other considerations are relevant. For instance, it is relevant to consider the effect of his impairment on his actions. The decision in Potts demonstrates that merely having an undoubted underlying condition which produces relevant impairments will not suffice unless those impairments were operative at the time of the offending; that is to say, unless the impairment explains in a significant way what happened. Clearly the impairment need not be total for that would constitute the mental illness defence. Partial mental incapacity is sufficient, but the extent necessary to reduce the legal liability of the accused is a matter for judgment.
74Moreover, in my opinion, the value judgment is not entirely at large. The decision involves normative considerations and the relevant legal norms must be derived from legal principle. One of the norms the statute embodies, derived from the criminal law generally, is that frequently, but not always, the criminal acts of the mentally ill or mentally disabled, justify less severe punishment than the criminal acts of persons of ordinary mental capacity. (cf Travel Compensation Fund v Tambree (t/as R Tambree and Associates) [2005] HCA 69; (2005) 224 CLR 627 at 639 [28] - [29] per Gleeson CJ).
75Applying these principles and disregarding the effect of the alcohol he had drunk, I am persuaded that the accused's impairment was so substantial as to justify reducing his criminal liability from murder to manslaughter.
76I am persuaded by the evidence I have recounted at [59] to [65] that, in lay terms, the accused's impairment was severe; particularly in his appreciation of the consequences of his actions, and his capacity for self-control. This severe impairment results from the combination of his mild to moderate intellectual disability, a lifelong disability in his case, and the frontal lobe damage, probably resulting from the affects of his unmedicated epilepsy. It is worth bearing in mind Dr Pulman's evidence that the accused's level of intellectual functioning falls in the extremely low range, 99.8 per cent of mature persons function at a higher level than him.
77The commission of the offence involved no planning or premeditation. It was a spontaneous attack without any thought at all to the consequences. The attack consisted of a series of blows lasting no more than a few seconds. His inability to control himself and his lack of appreciation of the consequences of his actions were the direct result of his substantial impairment. Applying the norms of the criminal law, which the statute embodies, as serious and severe as the attack was, his moral culpability is greatly reduced. Were this a normal criminal trial, I think the appropriate verdict would be manslaughter by reason of substantial impairment.