Partial Defences
59At trial, Mr Biddle pleaded not guilty to murder, but guilty to manslaughter on the basis of either or both of the partial defences I discuss below.
60At trial Mr Biddle submitted, on the evidence, that the jury would find that he was provoked and therefore guilty of manslaughter. However, consistent with the jury's verdict, I am satisfied that, provocation having been negatived beyond reasonable doubt by the Crown, Mr Biddle was not provoked into killing his wife.
61Mr Biddle also submitted that the jury ought to find, on the balance of probabilities, in his favour the partial defence of substantial impairment by abnormality of mind. At issue at trial was whether substantial impairment to Mr Biddle's capacity to control himself existed, and if so, whether it was sufficient to reduce liability from murder to manslaughter. In finding the prisoner guilty of murder, the jury must have answered no to either the former or the latter, of these elements of the partial defence.
62In order to make a finding on this issue, evidence of Mr Biddle's mental health history should be briefly reviewed.
63In seeking to understand the effect of this evidence, it is important to bear in mind that Mr Biddle, through his senior counsel, did not seek to elevate the fact of his mental health issues too highly. He conceded to the jury, that at the time of the murder, Mr Biddle fully knew what he was doing and knew that it was wrong: T394. This concession was properly made.
64Dr Hatton, a general practitioner with over 30 years' clinical experience, including many patients with mental health issues, gave evidence. He was Mr Biddle's general practitioner for more than 16 years.
65He reported that Mr Biddle presented with neurological symptoms in May 1993, and was subsequently hospitalised and diagnosed with lymphocytic choriomeningitis, which included some features of encephalitis.
66In June 2005, Mr Biddle reported symptoms of memory loss and irritability to Dr Hatton. Mr Biddle expressed concern as both his parents had been diagnosed with dementia in later life. Dr Hatton performed a mini mental state examination test, a relatively crude test, in which Mr Biddle scored 30 out of a possible 30. Results of blood tests and a brain CT scan reported no detectable abnormalities, and no further investigation was pursued.
67On 14 January 2009, following a visit and a request from Mr Biddle, Dr Hatton completed a report to the Firearms Registry at the New South Wales Police. The report was required to enable an assessment of Mr Biddle's suitability to hold a firearms licence. This reassessment was in response to the attempted self-harm episode two weeks earlier. Dr Hatton did not suggest he was making a detailed psychiatric assessment, but concluded that Mr Biddle " does not suffer from any psychiatric disorder ... [and Mr Biddle] does in my judgment have the ability to form a rational judgment or to exercise will power to control physical acts in accordance with rational judgment ". I accept this assessment of Dr Hatton. It is consistent with Mr Biddle's working capacity and ability at the time.
68I also find it to be particularly persuasive because it is, in time, the closest opinion of a medical practitioner to the killing of Mrs Biddle. As well, it is entirely uninfluenced by any suggestion or hint of hindsight bias arising unconsciously in later opinions, because the killing had occurred.
69It is also free of any of the effects on the character and mental state of Mr Biddle consequent upon the murder of Mrs Biddle, and the later, and increasing, effect of Mr Biddle being in custody.
70I recognise that Dr Hatton is not a specialist psychiatrist, but he is not without a good deal of clinical and practical experience in patients suffering from mental health issues.
71Further information about Mr Biddle comes from the various expert mental health professionals who examined him after the offence. The majority of these examinations occurred over one to two years later. The experts had different fields of speciality, and I will briefly summarise those parts of their evidence, which I accept.
72Evidence of Mr Biddle's brain function was provided by Dr Pulman, a neuropsychologist. Mr Biddle was examined and tested two years after the offence. That testing placed him in the lowest first to fifth percentiles in five out of six separate areas of testing, which included verbal comprehension, working memory, processing speed and general ability index. He scored an extremely low full scale IQ of 69. Dr Pulman concluded that Mr Biddle was in the range of someone who was mildly intellectually impaired.
73Dr Pulman said that the IQ score of 69, was less than she anticipated, having regard to her assessment of Mr Biddle's likely capacity to function before the murder. The other mental health experts broadly agreed with this assessment. The score stands in contrast to Mr Biddle's work history and his capacity to manage the farming activities that took place on the family property, albeit on a low scale.
74I am satisfied that the most likely reason to explain the discrepancy between the anticipated, and the actual IQ score, is that the testing occurred at a time when, as a consequence of the offence, his continued incarceration, and the loss of regular contact with his family, Mr Biddle was suffering depression. Depression was, as I was told by Dr Pulman, one cause of low IQ scores on the tests undertaken by Dr Pulman.
75Evidence of Mr Biddle's psychiatric state (his mind) was provided by Professor Greenberg, Dr Allnutt, Dr Nielssen and Dr Furst. All experts were in agreement that Mr Biddle suffered from an abnormality of mind, emanating from brain damage subsequent to meningoencephalitis in 1993, with concurrent depression. Two experts assessed the resulting impairment of capacity to control himself as substantial, one expert assessed it as mild and the remaining psychiatrist was not asked to make an assessment.
76Expert evidence of any disease or injury of Mr Biddle's brain was provided by Dr Rosen, a neurologist. He concluded the prisoner suffered from a significant brain injury subsequent to meningoencephalitis.
77Four letters written by Mr Biddle to his family after his arrest were admitted as evidence, and available to the above experts to assist in forming their conclusions, and also the jury.
78It is appropriate to note that the word "substantial" in the partial defence carries its ordinary meaning of being of substance, and not trivial, slight or insignificant. It does not indicate that the impairment of mind must necessarily have of itself, overborne Mr Biddle's capacity to control himself.
79On the basis of the entirety of the evidence regarding the prisoner's mental health status and nature of the offence, I find, consistently with the jury's verdict, that the prisoner's capacity to control himself was substantially impaired by brain damage subsequent to earlier meningoencephalitis, and concurrent depression. However, that impairment was not sufficient to warrant reducing his liability from murder to manslaughter, because I find that it played no causal role in the events which occurred.
80In summary I reach the following factual conclusions:
(a)As his counsel told the jury, Mr Biddle fully knew what he was doing to his wife, and fully knew that what he was doing was wrong;
(b)Mr Biddle acted rationally and deliberately. He left his accommodation, went to collect the murder weapon, an iron bar, surreptitiously entered the homestead by a rear door, surprised his wife and bludgeoned her to death, in a most vicious attack;
(c)Mrs Biddle, was aware of what was happening, tried to defend herself, but was helpless to do so as the attack persisted;
(d)At the time of the attack, Mr Biddle was not provoked. However, the breakdown of his marriage, for which his conduct had been the precipitatory cause, together with his inability to accept that his wife was entitled to an independent life and the fact that he could not reside in the homestead, all combined to bring him to decide to kill his wife;
(e)The killing of Mrs Biddle was the product of his selfish, perhaps narcissistic, personality, his determination to have control over his wife's behaviour and the way in which his family lived their lives.
Simply put, he was jealous of his wife, and her newly found independence. He could not accept that his previously comfortable life had irretrievably changed. He felt threatened by the loss of his dominant position in the family.
(f)It is clear that he lost proper control of his behaviour, and attacked his wife, intending to kill her and succeeded in so doing.