The State of Western Australia v Silich - [2011] WASCA 135

JURISDICTION : SUPREME COURT OF WESTERN AUSTRALIA

TITLE OF COURT : THE COURT OF APPEAL (WA)

CITATION: THE STATE OF WESTERN AUSTRALIA -v- SILICH [2011] WASCA 135

CORAM: MARTIN CJ
BUSS JA
HALL J

HEARD: 14 FEBRUARY 2011

DELIVERED : 28 JUNE 2011

FILE NO/S: CACR 61 of 2010

BETWEEN: THE STATE OF WESTERN AUSTRALIA
Appellant
AND
VERNON ROBERT SILICH
Respondent

FILE NO/S :CACR 64 of 2010

BETWEEN :VERNON ROBERT SILICH
Appellant
AND
THE STATE OF WESTERN AUSTRALIA
Respondent

ON APPEAL FROM:
Jurisdiction              :  SUPREME COURT OF WESTERN AUSTRALIA
Coram  :McKECHNIE J
Citation  :THE STATE OF WESTERN AUSTRALIA v SILICH
File No  :INS 195 of 2008

Catchwords:

Appeal - Criminal law - Offender appealing against conviction - Application by offender for an adjournment of the hearing of the appeal - Applicable principles - Whether offender had a reasonable opportunity properly to present his case on appeal

Criminal law - Evidence - Appeal of conviction - Admissibility of video record of interview - Discretion to exclude evidence on grounds of voluntariness, reliability and unfairness - Effect of intoxication - Admissibility of expert evidence - Whether sleepwalking comes within practice of psychiatry - Whether expert adequately qualified

Criminal law - Sentencing - State appeal against sentence - Murder - Offending towards middle range of seriousness for murders - Offender convicted of double murder of elderly parents - Life imprisonment with minimum period of 15 years before appellant eligible for release on parole - Whether minimum non-parole period manifestly inadequate - Proper approach to sentencing for murder under legislative scheme created by Criminal Law Amendment (Homicide) Act 2008 (WA) - Relevance of decisions under previous sentencing regime - Double murder as aggravating factor

Legislation:

Criminal Appeals Act 2004 (WA), s 39(1), s 39(3), s 40(1)
Criminal Code (WA), s 278, s 279(1), s 279(4), s 282, sch 1 cl 2
Criminal Law Amendment (Homicide) Act 2008 (WA)
Evidence Act 1906 (WA), s 32
Sentencing Act 1995 (WA), s 90(1)
Supreme Court (Court of Appeal) Rules 2005 (WA), r 38

Result:

Application for adjournment dismissed
Appeal on conviction dismissed
Cross-appeal on sentence allowed
Sentence of trial judge set aside in part
Appellant's minimum period required to serve before becoming eligible for parole set at 19 years for each count of wilful murder

Category: A

Representation:

CACR 61 of 2010

Counsel:

Appellant: Mr J McGrath
Respondent: Mr T F Percy QC

Solicitors:

Appellant: Director of Public Prosecutions (WA)
Respondent: D G Price & Co

CACR 64 of 2010

Counsel:

Appellant: Mr T F Percy QC
Respondent: Mr J McGrath

Solicitors:

Appellant: D G Price & Co
Respondent: Director of Public Prosecutions (WA)

Case(s) referred to in judgment(s):

Alexandroaia v The Queen (1995) 81 A Crim R 286
Atherden v The State of Western Australia [2010] WASCA 33
Austic v The State of Western Australia [2010] WASCA 110
Beamish v The Queen [2005] WASCA 62
Cleland v The Queen [1982] HCA 67; (1982) 151 CLR 1
Commonwealth v Howe (1857) 9 Gray 110
Dinsdale v The Queen [2000] HCA 54; (2000) 202 CLR 321
Easterday v The Queen [2003] WASCA 69; (2003) 143 A Crim R 154
Gallagher v The Queen [1986] HCA 26; (1986) 160 CLR 392
HG v The Queen [1999] HCA 2; (1999) 197 CLR 414
Hough v Ah Sam [1912] HCA 78; (1912) 15 CLR 452
House v The King [1936] HCA 40; (1936) 55 CLR 499
Kowaleff v The State of Western Australia [2010] WASCA 183
Lawless v The Queen [1979] HCA 49; (1979) 142 CLR 659
MacPherson v The Queen [1981] HCA 46; (1981) 147 CLR 512
Makita (Australia) Pty Ltd v Sprowles [2001] NSWCA 305; (2001) 52 NSWLR 705
Mallard v The Queen [2003] WASCA 296; (2003) 28 WAR 1
Mickelberg v The Queen [1989] HCA 35; (1989) 167 CLR 259
Mickelberg v The State of Western Australia [2004] WASCA 145; (2004) 29 WAR 13
Osland v The Queen [1998] HCA 75; (1998) 197 CLR 316
R v Buchanan [1966] VR 9
R v Burgess [1991] 2 QB 92
R v Lee [1950] HCA 25; (1950) 82 CLR 133
R v Ostojic (1978) 18 SASR 188
R v Parenzee [2008] SASC 245; (2008) 101 SASR 469
R v Parks [1992] 2 SCR 871
R v Smith (1992) 58 SASR 491
R v Smith [1979] 3 All ER 605
R v Swaffield [1998] HCA 1; (1998) 192 CLR 159
R v Williams (1992) 8 WAR 265
Ratten v The Queen [1974] HCA 35; (1974) 131 CLR 510
Rinaldi v The State of Western Australia [2007] WASCA 53
Sali v SPC Ltd [1993] HCA 47; (1993) 67 ALJR 841
Sinclair v The King [1946] HCA 55; (1946) 73 CLR 316
The State of Western Australia v O'Kane [2011] WASCA 24
The State of Western Australia v Singh (Unreported, 1 October 2010, INS 97 of 2010)
Tofilau v The Queen [2007] HCA 39; (2007) 231 CLR 396
Urbano v The State of Western Australia [2006] WASCA 147
Van Der Meer v The Queen [1988] HCA 56; (1988) 62 ALJR 656
Wendo v The Queen [1963] HCA 19; (1963) 109 CLR 559

MARTIN CJ:

Summary

The appellant, Vernon Robert Silich, appeals from his conviction on two counts of wilfully murdering his parents, Robert and Faye Silich. Following his conviction, he was sentenced to life imprisonment with a minimum period of 15 years to be served prior to eligibility for parole on each count. The State appeals against that sentence on the ground that the minimum period required to be served prior to eligibility for parole is manifestly inadequate.
For the reasons which follow, the appeal against conviction should be dismissed. The State's appeal against sentence should be allowed, the minimum period required to be served prior to eligibility for parole imposed by the sentencing judge set aside, and instead the appellant sentenced to life imprisonment with a requirement that he serve 19 years imprisonment prior to eligibility for parole on each count.

The facts

The evidence adduced at trial established the following facts, which were not seriously in contention, beyond reasonable doubt.
Prior to the events giving rise to the charges against the appellant, he enjoyed a loving and caring relationship with his parents. On the evening of 8 April 2008, the appellant visited his parents at their home in Yokine for the purpose of having dinner with them. He took with him a bottle of Scotch which he had been given by friends and some beer. During the course of the evening, the appellant and his father drank beer and some of the Scotch. Each consumed a substantial amount of alcohol. In addition, although there was contention on this issue at trial, the trial judge found, for the purposes of sentence, that the appellant smoked three joints of cannabis during the course of the evening.
During the evening, the appellant discussed the recent death of the appellant's brother, Murray, with his parents. However, the evening was otherwise uneventful, and three friends who telephoned the appellant during the course of the evening did not detect anything untoward in the appellant's behaviour, or in the family dynamic.
The appellant's father went to bed at about 11.30 pm. Although the appellant said in evidence that his mother went to bed at about 12.40 am, the fact that she was found in her day clothes makes this evidence improbable, and the trial judge found, for the purposes of sentence, that she had not gone to bed. At all events, the appellant stayed sitting at the kitchen table drinking alcohol. It is clear that he became heavily intoxicated.
At some point during the evening, the appellant entered his father's bedroom, and attacked his father in his bed. The appellant also attacked his mother in the bedroom. The appellant kicked each of his parents with considerable force. He was wearing steel capped boots. The kicks were aimed at the upper part of their bodies, and were not random, but were found by the trial judge for the purpose of sentence to have been directed in a manner that would cause death. The force of the blows caused unconsciousness, and ultimately death. Following the attacks, the bodies of the deceased were arranged so that their hands were adjoining (ts 65). The bodies must have been placed in that position by the appellant.
At about 3.45 am on the morning of 9 April 2008, the appellant telephoned his friend, Mr Michael Jurotte. The appellant asked Mr Jurotte to come to his parents' house. Mr Jurotte arrived at the house a few minutes later and found the appellant in the front driveway. The appellant appeared 'pretty intoxicated' (ts 106). The appellant said to Mr Jurotte that he did not know what had happened, and that he 'just went beserk' (ts 107). He then invited Mr Jurotte to go into the house and 'have a look'. Mr Jurotte entered the house and discovered the bodies of the deceased. He returned to the appellant who repeated that he did not know what had happened, but that he had 'gone beserk' (ts 108). The appellant also said that 'he thought he'd fallen asleep in a cat house and someone had stolen his wallet' (ts 108). Mr Jurotte took the reference to 'cat house' to be a reference to a brothel (ts 108).
Mr Jurotte returned to the house and got some beer out of the fridge. He returned to the front yard of the house, where he and the appellant each had a beer and smoked cigarettes. Mr Jurotte advised the appellant that he would have to call the police, and the appellant said, 'Yeah, I know' (ts 109).
Mr Jurotte telephoned the police. The attending officers observed that the appellant was affected by alcohol. He appeared unsteady on his feet and alcohol was smelt on his breath (ts 83).
The appellant was taken into custody, and conveyed to the Morley police station at around 6 am. The appellant was not interviewed by police at that point, because they did not consider him to be sufficiently sober (ts 98).
During the morning, the appellant had some sleep and was provided with coffee and food (ts 98).
At 12.56 pm on 9 April 2008, a blood sample was taken from the appellant. The blood alcohol content of that sample was 0.138% (ts 561).

The police interview

At 2.22 pm on 9 April 2008, the appellant participated in an interview with police which was recorded by video: GAB 35 ‑ 36. This was about an hour and a half after the blood sample had been taken.
The evidence of Mr Jason White, a pharmacologist, was that generally speaking, the body eliminated alcohol at the rate of 0.015% per hour (ts 381), from which it could be inferred that the appellant's blood alcohol level at the time of his interview would have been about 0.116%. However, there was no evidence as to the effect which such a level of alcohol would have had upon the appellant's mental faculties at the time of his interview.
At the commencement of the interview, the appellant was advised that anything he said would be recorded, and might be used in evidence against him. He was further advised that he was not obliged to answer questions if he did not want to, and he confirmed that advice. On a number of occasions during the interview, the appellant declined to answer questions that were put to him.
During the interview the appellant said that he had been living at his parents' house in Yokine for 'a while', and that he had lived there all his life. He denied living anywhere else recently. These statements were untrue, as the appellant had been living at premises in Nollamara for some years.
During the interview the appellant said that he had been drinking up until 'the incident'. He stated that he had not gone to bed, and that he was 'still up'.
Counsel for the appellant foreshadowed an objection to the admissibility of the video record of interview on the grounds that it was not voluntary or, alternatively, should be excluded in the exercise of discretion, on the grounds that the admissions made in the interview were not reliable, or that it would be unfair for the prosecution to rely upon them. The parties sought a ruling on the admissibility of the record of interview prior to trial. They were content to put their submissions on the subject of admissibility entirely in writing. The trial judge gave his ruling on the admissibility of the video at the pre‑trial voir dire in the following terms:
I consider that the video record is admissible and I see no reason to exclude it in the exercise of discretion. There is an issue about the amount of alcohol that the accused had taken and the extent to which he was under the influence at the time and the police officers did not ask him, as normally happens, whether he was fit but I have observed the video twice and consider that the questions he answered were voluntary and the reliability is not such that comes off the page to exclude it in the exercise of discretion. So the video is admissible (ts 150).

The trial

At the commencement of the trial, the appellant made formal admissions through his counsel as to the identity of each deceased, and that each died as a result of injuries inflicted by the appellant on the day and at the time alleged in the indictment (ts 9). As a consequence, the issues that were litigated during the trial, and which the jury were required to determine were:
(a)the intention of the appellant at the time he committed the acts causing the death of his parents, and in particular, whether the State established beyond reasonable doubt that he intended to kill each of his parents, so as to sustain convictions for wilful murder, or if not, that he intended to cause each of his parents grievous bodily harm so as to sustain convictions for murder, particularly having regard to his level of intoxication; and
(b)whether there was a reasonable doubt that the appellant was acting involuntarily at the time he committed the acts causing the death of his parents, because he was sleepwalking.
The prosecution case was that the jury should conclude beyond reasonable doubt that the appellant intended to kill his parents at the time he inflicted the blows which caused their death because:
(a)the blows were directed towards the head and upper body of each deceased, and applied in a manner which was likely to cause death;
(b)the severe and sustained nature of the attack on each deceased was only consistent with an intention to kill;
(c)the appellant had sufficient mental capacity to perpetrate the attacks, then arrange the bodies so that the hands of the deceased were juxtaposed and sufficient mental capacity to telephone Mr Jurotte for help, rather than the police or an ambulance. He also had sufficient mental capacity to arrange for his rent to be paid prior to his arrest;
(d)there was no evidence that the appellant was sleepwalking at the time he perpetrated the attack upon his parents - to the contrary, he admitted to police during the recorded interview that he had been up all night and had not gone to sleep.
The prosecution called a psychiatrist, Dr Frank Varghese, to give evidence on the subject of sleepwalking. The admissibility of that evidence was tested during a voir dire, after which the trial judge ruled the evidence to be admissible (ts 249).
The defence case was that the jury could not be satisfied that the appellant was not sleepwalking at the time he kicked his parents, with the consequence that the State had failed to prove beyond reasonable doubt that his acts of kicking his parents were voluntary, with the result that he was entitled to be acquitted on all counts. Alternatively, the defence contended that the appellant's intoxication was such that the jury could not be satisfied beyond reasonable doubt that he had the intention necessary to sustain a conviction for either wilful murder or murder, with the result that the appellant should be convicted of manslaughter.
The appellant gave evidence (ts 293 ‑ 357). His evidence was that he had arrived at his parents' house at about 5 pm on 8 April 2008. After dinner, he was told by his father that the coroner's report relating to the death of his brother, Murray, revealed that he had died from a drug overdose rather than a pacemaker malfunction, as they had previously suspected. He denied that this information caused any friction between him and his parents.
The appellant stated that he had taken beer and Scotch to his parents' house, and that between the time he arrived at his parents' house, and the time when he called Mr Jurotte the following morning, he would have consumed about a dozen stubbies of beer. He also stated that he had smoked a couple of joints of cannabis in the backyard during the evening. He also drank some of the Scotch.
The appellant stated that his mother had stayed up after his father had gone to bed, and that he remained drinking and talking with her until she went to bed at about 12.40 am. He stated that he went to sleep in the lounge room, fully clothed, about half an hour after his mother had gone to bed. The next thing he could recall was voices, the sound of a dog barking, and he thought the house was being broken into. He stated that he was 'very drunk' at that time (ts 338).
The appellant's evidence was that he woke up and found his parents lying on the floor, after which he panicked and 'freaked out'. He stated that he had no idea how his parents' hands came to be placed over each other. He also stated that he had no memory of kicking his parents (ts 312).
The defence called Mr Jason White, a pharmacologist, to whose evidence I have already referred. His evidence was to the effect that, having regard to the test which revealed that the blood alcohol level of the appellant was 0.138% at 12.56 pm on 9 April 2008, his best estimate of the appellant's blood alcohol level at the time of the attack upon his parents was between 0.23% and 0.397%, depending upon whether the attack occurred around midnight, or at 3.45 am, or some time in between (ts 381). Mr White also gave evidence as to the effect which such an alcohol level would have upon the appellant's capacity to form an intention, as did a psychiatrist called by the defence, Dr Victoria Pascu.
The defence also called a respiratory physician, Dr Jack Philpott (ts 399 ‑ 460). The evidence of Dr Philpott was that he spent around 60% - 70% of his professional time dealing with sleeping problems such as sleep apnoea. Those problems were addressed in part through a sleep laboratory which Dr Philpott conducted at a Perth hospital.
Dr Philpott gave evidence on the general subjects of parasomnia and somnambulism (sleepwalking). He also gave evidence of a sleep study that he had conducted on Mr Silich on 24 October 2009. His evidence was to the effect that the study confirmed that the appellant suffered from obstructive sleep apnoea which disrupted his sleep. Dr Philpott described Mr Silich as suffering from mild sleep apnoea. The test revealed no evidence of parasomnia or somnambulism. Nevertheless, based upon the history which Dr Philpott had taken from the appellant, and from histories he had taken from others who had observed the appellant sleepwalking, his diagnosis was that the appellant committed the attacks upon his parents during an episode of violent somnambulism.
The defence also called evidence from friends of the appellant, Mr Rule, and Mr Low, who had each given histories to Dr Philpott to the effect that they had observed the appellant sleepwalking. They confirmed those observations in evidence (ts 357 ‑ 368, 370 ‑ 377).
As I have mentioned, the jury returned a verdict of guilty on each of the counts of wilful murder (ts 385). The appellant makes no complaint with respect to the directions given to the jury by the trial judge.

The adjournment application

At the commencement of the hearing of the appeal on 14 February 2011, counsel for the appellant sought an adjournment. He did so in reliance upon an affidavit of the appellant sworn on 4 February 2011. In that affidavit, the appellant deposes that on 21 December 2010, he saw a television programme concerning the issue of sleepwalking as a cause of motiveless homicide. He further deposes that on 29 December 2011 [sic 2010], he observed another programme which dealt with similar issues. The appellant deposes that, as a consequence of viewing those programmes, he believes that there may be evidence available on the subject of sleepwalking that could cast doubt on his conviction, which evidence was previously unknown to him, his solicitors, or his medical advisors. He further expresses the belief, presumably based upon what he saw in the television programmes, that the science of the analysis of sleepwalking may be more advanced in Europe and America than either he or his legal advisors had previously known. For that reason, he sought an adjournment to enable his solicitors to contact medical experts in Europe and America in order to ascertain whether there is any scientific evidence that could shed light on the circumstances of the death of his parents.

The appellant deposes that as soon as he saw the first programme, he instructed his solicitors to contact the experts identified in that programme. However, Mr Silich asserts that he was advised by his solicitors that there would be insufficient time to locate and brief an expert prior to the hearing of the appeal, and that the costs involved would be significant. Mr Silich further deposes that as a result of the dismissal of charges that had been brought against him on 2 February 2011, assets previously frozen under legislation relating to the proceeds of crime had been freed up, which he would be able to utilise to meet the expenses involved in briefing additional experts.
After hearing argument, the court refused the application for an adjournment on the basis that reasons for that refusal would be given as part of the reasons dealing with the substantive disposition of the appeals. My reasons for joining in the refusal of the adjournment follow.
There is a strong public interest in the timely disposition of all criminal cases, including criminal appeals. In most cases, those who are interested in the final resolution of a criminal case are not limited to the prosecutor and the accused. In addition to the public interest in the final resolution of serious criminal cases such as this, there will often be others with a specific and identifiable interest in the timely conclusion of the proceedings. In the present case, it is reasonable to infer from the victim impact statement that was provided by the appellant's brother, that there are members of the appellant's family who have a very real interest in the closure of issues relating to the deaths of their parents and grandparents in horrific circumstances. Public resources provided to the prosecution and the court are also dissipated every time there is a late adjournment. In this sense, the interests of the parties are to be balanced with the effect of the adjournment on 'court resources and the competing claims by litigants in other cases awaiting hearing': Sali v SPC Ltd [1993] HCA 47; (1993) 67 ALJR 841, 844 (Brennan, Deane and McHugh JJ).
While these are important and weighty considerations, they will necessarily be subordinated to the interests of justice in a case in which it is established that the refusal of an adjournment would deprive an accused, or an appellant, of the opportunity to present a case which has a real prospect of success. However, this is not such a case.
The grounds upon which the adjournment was sought in this case are amongst the most vague that could be imagined. The court has been provided with only the most vague and general description of the television programmes in question, and has not been provided with any basis upon which any realistic assessment could be made of the likelihood of any relevant evidence being obtained as a result of the inquiries which the appellant wishes to conduct. No prospective witnesses have been identified, beyond the vague assertion that there may be unidentified experts somewhere in Europe or North America who might be able to express some unidentified view that may (or may not) be relevant to the issues in the appellant's case, and which may (or may not) support the appellant's case.
The programmes were viewed by the appellant seven weeks prior to the scheduled hearing of the appeal. The application for an adjournment was made shortly before the appeal was due to be heard. This delay is contrary to r 48 of the Supreme Court (Court of Appeal) Rules 2005 (WA), which requires that an application for an adjournment must be made 'immediately' if it is known that an adjournment is wanted. No explanation has been provided as to why information has not been sought from Australian experts, such as Dr Philpott, on the subject of whether there may be experts in other countries who might be able to give evidence on these issues which is not available within Australia. Nor has the court been advised whether Dr Philpott was asked prior to trial whether overseas expertise should be sought, or whether any inquiries were made as to the extent of the expertise available in other countries prior to trial.
Because of the strong public interest in the finality of the criminal trial process (R v Parenzee [2008] SASC 245; (2008) 101 SASR 469 [55] (Doyle CJ)), the circumstances in which additional evidence will be admitted in a criminal appeal are limited (Urbano v The State of Western Australia [2006] WASCA 147 [8] ‑ [10] (McLure JA)). In cases in which additional evidence is admitted on appeal, the principles to be applied in the resolution of the appeal will depend upon whether the additional evidence is fresh evidence or merely new evidence: Mickelberg v The State of Western Australia [2004] WASCA 145; (2004) 29 WAR 13 [411] ‑ [415] (Steytler J). Evidence will only be characterised as 'fresh' if it is evidence which either did not exist at the time of trial, or which could not then have been discovered with reasonable diligence. New evidence is evidence which was available at the trial, or which could then have been discovered with reasonable diligence (Mickelberg [411]).
The vagueness of the ground upon which the adjournment is sought in this case does not enable the court to evaluate whether any evidence which might arise from the inquiries which the appellant seeks to conduct would be 'fresh' or merely new. Given that the trial was conducted less than a year prior to the hearing of the appeal, it seems unlikely that the scientific principles addressed in the television programmes which the appellant saw (whatever they may be) would not have been known at the time of trial. And, as I have mentioned, the court was not told whether the expert who was called by the appellant at trial, Dr Philpott, was asked whether there were other experts overseas who might be in a position to give evidence of matters beyond his expertise either before trial or more recently, or whether any other inquiries were made with respect to overseas expertise prior to trial.
If additional evidence received on appeal is properly characterised as 'fresh', the appeal will be allowed and the conviction quashed if the appellate court concludes that the evidence has sufficient cogency to establish a significant possibility that if it had been adduced at trial, in the light of all the other evidence, a jury acting reasonably would have acquitted the appellant: Gallagher v The Queen [1986] HCA 26; (1986) 160 CLR 392, 399 (Gibbs CJ), 402 (Mason and Deane JJ); Mickelberg [417] (Steytler J). However, where the evidence is merely new, and not 'fresh', the verdict will only be disturbed if the appellate court is satisfied that the evidence carries sufficient cogency to establish the innocence of the appellant: Lawless v The Queen [1979] HCA 49; (1979) 142 CLR 659, 675 ‑ 676 (Mason J).
The vagueness of the basis upon which the adjournment was sought provides no basis whatever for any assessment of the cogency of any evidence that might be adduced following the inquiries which the appellant wants to undertake, or whether there is any prospect that such evidence might result in an arguable ground of appeal. Any attempt to make an assessment of such a prospect would be utter speculation, entirely devoid of any evidentiary foundation.
Accordingly, the grounds upon which the adjournment was sought provided no basis whatever for interfering with the various considerations which support the orderly disposition of this appeal by proceeding with the hearing at the time allotted.

Ground 1

Ground 1 challenges the ruling of the trial judge prior to trial to the effect that the video record of the interview of the appellant by police was admissible. The ground relies upon essentially the same propositions as were put to the trial judge - namely, that the video record of interview should be excluded on the ground that it was given involuntarily, or in the exercise of discretion on the basis of unreliability or unfairness.

Voluntariness

It is, of course, well established that in order to be admissible, a statement by an accused person that contains admissions against interest must have been made voluntarily; that is, 'made in the exercise of a free choice to speak or be silent': R v Swaffield [1998] HCA 1; (1998) 192 CLR 159 [50] (Toohey, Gaudron and Gummow JJ). A statement will not have been made voluntarily if the will of the maker of the statement has been overborne, perhaps as a consequence of a threat or promise made by a person in authority: MacPherson v The Queen [1981] HCA 46; (1981) 147 CLR 512, 519 (Gibbs CJ and Wilson J); Tofilau v The Queen [2007] HCA 39; (2007) 231 CLR 396 [2] (Gleeson CJ).
In the absence of evidence to the contrary, it is presumed that an admission against interest was made voluntarily: Hough v Ah Sam [1912] HCA 78; (1912) 15 CLR 452, 457 (Barton J); R v Williams (1992) 8 WAR 265, 271 (Rowland and Owen JJ). However, if there is evidence which casts doubt on the voluntariness of the statement, the State must prove on the balance of probabilities that the statement was made voluntarily: R v Lee [1950] HCA 25; (1950) 82 CLR 133, 144; MacPherson (522) (Gibbs CJ and Wilson J).
There is no direct evidence that the accused did not participate voluntarily in the interview with police. To the contrary, the direct evidence is to the effect that he participated voluntarily. As I have noted, at the commencement of the interview, the appellant was advised that he was not obliged to answer any questions, and he confirmed that he understood that advice. His awareness of his right to decline to answer questions put to him was demonstrated a number of times during the interview, when he exercised that right. Further, when the accused gave evidence at trial, he did not suggest at any point that he did not participate in the interview voluntarily. On the contrary, he gave evidence in chief to the effect that the statements made to police were correct, as best as he could recall, at the time he made them (ts 320), although he did say that he regretted giving the interview because he was not in a good 'state of mind' (ts 341).
The words, conduct and demeanour of the appellant depicted in the video record of interview itself do not evoke any suggestion of any disinclination or reluctance to participate in the interview. At the conclusion of the interview, the accused was asked if he had any complaints about the way in which he had been treated by police that day, and the accused responded that he had no complaint, and made a positive statement about the cigarettes he had been offered by police. He further confirmed that he understood everything that had happened during the day. When asked whether he had participated voluntarily in the interview, without any promises or threats being made, he facetiously replied 'not yet'. The facetiousness of that remark suggests that the appellant had not only had his wits about him, but also that he had not been overawed by the enormity of the events which had taken place. At all events, when the question was repeated, the appellant confirmed that he had not been offered any inducement in order to participate in the interview.
Given the body of evidence which strongly supports the conclusion that the appellant participated voluntarily in the interview with police, counsel for the appellant was driven to rely upon the evidence of the appellant's intoxication at the time he participated in the interview. As I have noted, the evidence suggests that the level of alcohol in the appellant's blood at the time the interview commenced would have been around 0.116%. As the pharmacological evidence confirmed, the levels of alcohol in the appellant's blood, and his intoxication, would have been much greater earlier in the day. That is why the police did not interview the appellant at the time of his arrest but rather, provided him with the opportunity to sober up, get some sleep, and to have coffee and food (although it seems the appellant may have declined food on the basis that he was not hungry).
In Sinclair v The King [1946] HCA 55; (1946) 73 CLR 316, Dixon J observed that mental impairment by the maker of a statement against interest did not necessarily mean that the statement was inadmissible in criminal proceedings brought against the maker of the statement, even if, as a consequence of the mental impairment, the maker of the statement was 'confusing the products of his disordered imagination or fancy with fact' at the time of making the statement (338). The statement will be admissible if the mental state of the accused did not 'disable him from observing, appreciating, recollecting and recounting real occurrences, events or experiences' (337). In the same context, Dixon J cited Commonwealth v Howe (1857) 9 Gray 110 as authority for the proposition that a confession made by an intoxicated defendant is admissible in evidence against him unless 'the degree of intoxication is so great as to deprive him of understanding what he was confessing' (336). Accordingly, a statement made against interest will be admissible if, despite mental impairment, the accused was capable of giving a true account of events.
In R v Ostojic (1978) 18 SASR 188, an admission made by an intoxicated accused was ruled to be admissible on the basis of the trial judge's conclusion that, notwithstanding his intoxication, the accused was capable of giving a detailed account of his movements and actions on the night in question. The admission of the confession into evidence was upheld on appeal. Wells J (with whom King and Hogarth JJ agreed) observed:
I could imagine one type of drunken person who is far gone in liquor and who, in the circumstances, is so plainly unaware of his surroundings, of the identity of his interrogator, and of the drift of the questions put, that he is incapable of choosing whether to speak or not, and is just gabbling. It would not be a wholly unacceptable proposition that what he said was not voluntary.
…
It is a question of fact and degree (197).
Similarly, in R v Williams, the majority upheld a ruling by the trial judge to the effect that a confession was made voluntarily by the accused notwithstanding his intoxication (277), although the confession was ultimately excluded on the ground of unfairness.
Accordingly, in the present case, the question of voluntariness is to be determined by asking whether, on the balance of probabilities, the appellant was so intoxicated at the time of his interview by police that he was incapable of choosing whether or not to participate in the interview, or to understand the questions being asked and provide reasonable responses to those questions. The evidence to which I have already referred compels the conclusion that the appellant's participation in the interview was voluntary, in the sense described in the authorities to which I have referred.
The appellant was plainly capable of deciding whether or not to participate in the interview. He said that he was, and demonstrated that capacity by declining to answer specific questions on a number of occasions. Further, during the interview, the appellant demonstrated his capacity to understand the questions that were put to him, and to provide coherent answers to those questions. At the conclusion of the interview, he confirmed that he had understood the process and had no complaints with the way he had been treated. During his evidence at trial, as I have noted, he stated that the answers he had given police were given to the best of his recollection and ability.
In the end, the argument advanced on behalf of the appellant on this issue seemed to come down to the proposition that through some unspecified process of reasoning, notwithstanding all the evidence to which I have referred, the court should nevertheless conclude that the participation of the appellant in the interview was involuntary because his blood alcohol level was in the vicinity of 0.116% at the time. One of the difficulties with that proposition is that, as I have mentioned, there is no evidence as to the effect which such a level of alcohol would have upon the mental faculties of the appellant. Nor is there any basis upon which the court could take judicial notice of the likely effect of such a level of alcohol in the blood, given the notorious fact that different levels of alcohol may affect behaviour and mental faculty differently, depending on the individual, and their experience with alcohol.
There is no substance in the proposition that the appellant did not participate voluntarily in the interview with police and this aspect of ground 1 must be rejected.

Reliability

In R v Swaffield, Toohey, Gaudron and Gummow JJ observed that unreliability was an important aspect of the discretion to exclude confessional evidence on the ground of unfairness.
The submissions put on behalf of the appellant in support of this aspect of ground 1 rely not only upon the appellant's intoxication at the time of his interview, but also upon the evidence of his much greater intoxication at the time of the events about which he was questioned. The evidence of Mr White, the pharmacologist, was that the level of intoxication experienced by the appellant in the early hours of the morning was so great as to create a risk of memory loss (ts 387). However, as with the submissions put on the subject of voluntariness, the difficulty which this submission faces is that the possibility of substantial memory loss is negated by the direct evidence given by the accused at trial, to the effect that the answers given were his best recollection of the events, and of the evidence of those events which he gave at trial. The pharmacological process described by Mr White would have resulted in the permanent loss of memory of those events, but, of course, the appellant gave evidence at trial of many events which took place on the night in question, and cannot therefore have suffered complete memory loss.
The statements made by the accused during the course of his interview do not suggest any general lack of recollection of the events of the evening, save for his failure to provide any information as to the specific events which caused the death of his parents. That failure, whether deliberate or due to lack of recall, does not render the statements which he made relating to matters which he could recall unreliable.
It was sought to bolster the argument advanced on behalf of the appellant on this issue by reference to the false statements which he made to police in relation to his place of residence. However, in his evidence at trial, the appellant sought to explain that evidence by the fact that he had always used his parents' address for paperwork such as his driver's licence and so forth (ts 319). He did not suggest that his false statements to police were to be explained by confusion or lack of recollection. Of course, there may be many explanations for the making of false statements in an interview with police other than lack of recollection or confusion. One that was suggested in the course of argument was the proposition that the appellant may have been attempting to conceal his true address from police because illegal drugs were later found at that address. Whether or not that proposition is true is not to the point. Rather, the point is that an inference of general unreliability cannot be drawn merely from the making of statements during the course of the interview that are false, especially when many other statements made by the appellant during the course of his interview were corroborated by the evidence which he gave at trial.
The question of whether the intoxication of the appellant at the time of the events which resulted in the death of his parents was so great as to impair his recollection of those events was a matter for the assessment of the jury having regard to all the evidence which it heard. That evidence included the pharmacological evidence given by Mr White. It also included the evidence of those things which the appellant was capable of doing in the early hours of the morning, including deciding to make, and making a telephone call to his friend, Mr Jurotte, rather than calling the police or an ambulance. Other evidence before the jury which bore directly upon that topic was the evidence of the events of the evening given by the accused himself.

On the other hand, the question of whether the statements made by the appellant during his interview were so unreliable as to be excluded from evidence in the exercise of the discretion to exclude evidence which would be unfair to an accused was a question for the trial judge. For the reasons I have already given, the level of alcohol in the blood of the appellant at the time he was interviewed by police does not, of itself, support the conclusion that the statements he made to police were unreliable, and there is a considerable body of direct evidence to the contrary. Accordingly, the proposition that the trial judge should have concluded that the admissions against interest made by the appellant during his interview with police were so unreliable as to be excluded from evidence lacks any real substance, and must be rejected.

Unfairness

'In considering whether a confessional statement should be excluded, the question is not whether the police have acted unfairly; the question is whether it would be unfair to the accused to use his statement against him': Van Der Meer v The Queen [1988] HCA 56; (1988) 62 ALJR 656, 666 (Wilson, Dawson and Toohey JJ).
The discretion to exclude a voluntary confession on the ground of unfairness is not limited to cases in which the confession has been procured by unlawful or improper conduct on the part of police, but extends to all cases in which admission of the evidence would be unfair to the accused: R v Williams (273) (Rowland and Owen JJ). In R v Williams, the confessional material was excluded on this ground. However, the accused in that case was much more intoxicated than the appellant in this case at the time of questioning, had suffered brain damage and had a low IQ, and behaved abnormally during the interview, for example, by hitting his head on the wall. Those circumstances are very different to the circumstances in which the appellant was interviewed in the present case. Once again, the submissions advanced in support of this aspect of ground 1 rely significantly upon the intoxication of the appellant at the time of interview. In this aspect of the ground, they are coupled with the proposition that the trauma of the events which had taken place earlier in the day, and his high level of intoxication at the time of those events, support the conclusion that admission of the statements made during the course of the interview into evidence would be unfair to the appellant.
On the other hand, as I have pointed out, at the time the appellant was apprehended, the police declined to conduct an interview because of his insobriety. The appellant was given an opportunity to sleep, provided with coffee and offered food. He participated voluntarily in the interview which was conducted about nine hours after he was apprehended. There is nothing in the record of interview which would suggest that the appellant's behaviour or demeanour was aberrant, or which suggested mental impairment either as a result of drunkenness or traumatic experience. To the contrary, the appellant's capacity to comprehend the questions put to him, his exercise of the right to decline to answer some of the questions put to him, and the coherence with which he answered many of the questions put to him tell strongly against the proposition that it would be unfair to the accused to admit his statements into evidence. Further, as I have already observed, the facetious comment made by the appellant at the conclusion of the interview supports the conclusion that he had not been emotionally or intellectually overborne by the traumatic events of the morning.
For these reasons, there is no substance in the proposition that the trial judge erred by failing to exercise his discretion to exclude the video record of interview from evidence on the ground of unfairness to the appellant.
Ground 1 should be dismissed.

Ground 2

Ground 2 challenges the decision of the trial judge, following a voir dire, to admit the evidence of Dr Varghese. Particulars given in support of the ground suggest that the evidence should have been excluded on the basis that Dr Varghese lacked appropriate qualifications or experience in 'sleep medicine or sleep science', was not qualified to conduct a sleep study, and failed to demonstrate current knowledge of the relevant literature relating to 'sleep medicine or sleep science'.
When issues concerning the admissibility of expert evidence arise, at least two questions must be addressed. The first is whether the evidence which it is proposed to adduce concerns matters about which ordinary persons are unable to form a sound judgment without the assistance of those possessing special knowledge or experience or expertise in the area, and in respect of which there is a body of knowledge which is recognised as a reliable body of knowledge or expertise: see Osland v The Queen [1998] HCA 75; (1998) 197 CLR 316 [53] (Gaudron and Gummow JJ); Mallard v The Queen [2003] WASCA 296; (2003) 28 WAR 1 [242].
In the present case, parasomnia and somnambulism, and the mechanisms which might cause a dissociative state in which a person's actions may occur independently of their free will and therefore involuntarily are matters outside the realm of ordinary experience, and are subjects upon which the jury is entitled to receive the benefit of expert evidence: R v Smith [1979] 3 All ER 605, 611.
The second question which must be addressed is whether the proposed witness has expertise in the relevant field by reason of specific training, study or experience: Makita (Australia) Pty Ltd v Sprowles [2001] NSWCA 305; (2001) 52 NSWLR 705 [85] (Heydon JA).
The particulars and argument advanced in support of this ground of appeal are based upon a misconception of the field of expertise that was relevant to this case. The critical question was whether there was a reasonable possibility that the appellant's actions, in kicking his parents to death, had occurred independently of the exercise of his free will because he was sleepwalking. The issues involved were those associated with parasomnia, somnambulism and dissociative mental states. While these may be aspects of a broader field loosely described as 'sleep science or sleep medicine', the evidence clearly established that they were also aspects of the field of psychiatry, in which Dr Varghese was qualified.
The evidence given on the voir dire established that Dr Varghese qualified as a medical practitioner in 1972, and in the specialist field of psychiatry in 1978 (ts 252). He is an associate professor in psychiatry at the University of Queensland, and also conducts a private practice. He has held various academic, clinical and professional appointments in the field of psychiatry throughout a lengthy career in that field. He has received a number of research grants funding research in the field of psychiatry, and has published many books, chapters and articles on a variety of topics in the field of psychiatry. He has also presented extensively at conferences in that field. Most recently, Dr Varghese has specialised in the area of forensic psychiatry, and has given evidence in a number of criminal cases in which psychiatric issues were involved (ts 236). In that capacity, he has experience of two previous criminal cases in which issues relating to sleepwalking arose. Outside the criminal area, Dr Varghese has experience of several dozen cases in which issues arose as to dissociative sleepwalking (ts 237).
Dr Varghese gave evidence that the standard manual of classification relating to psychiatric disorders was the Diagnostic and Statistical Manual of the American Psychiatric Association (known as the DSM). He expressed the view that the DSM was accepted within the practice of psychiatry in Australia. Parasomnia and other sleep disorders are classified in the DSM (ts 244).
Dr Varghese's evidence was that the diagnosis of sleepwalking fell within the field of psychiatry. When issues relating to sleep disorders arose, psychiatrists would often liaise with respiratory physicians who were qualified to assess sleep apnoea, perhaps through conducting a sleep study. Dr Varghese had, himself, liaised with respiratory physicians in relation to these issues. In such a relationship, the role of the respiratory physician was focused upon the identification of the sleep disorder, whereas the role of the psychiatrist was focused upon the psychiatric consequences of that disorder (ts 237 ‑ 238).
During cross‑examination on the voir dire, Dr Varghese asserted that while respiratory physicians are qualified to conduct and interpret sleep studies, dissociative behaviours associated with sleep disorders fell within the field of psychiatry (ts 291). He accepted that he had never conducted a sleep study, although he had observed such a study conducted. He also accepted that he was not qualified to interpret the results of a sleep study, as that field fell within the expertise of a respiratory physician (ts 240).
Dr Varghese also conceded that he had never specialised in the field of sleep medicine, or attended conferences run by associations focused upon sleep disorders (ts 241). That was because such conferences were mainly about the physiology of sleep, whereas his focus was upon the dissociative condition of the brain as a result of a sleep disorder.
He also accepted that he had not treated sleep apnoea, although he had treated insomnia which was the commonest psychiatric symptom (ts 242).
Dr Varghese testified that the most recent edition of the DSM which had been published was published in 2000, being a revision of a draft published in 1994. He expressed reservations about the classification system embodied in the DSM. He also accepted that a specialist respiratory physician would be unlikely to make reference to the DSM (ts 243).
During cross‑examination an alternative classification system (ICSD‑2) was put to Dr Varghese, being a classification system for sleep disorders. Dr Varghese was aware of the classification system (ts 244).
Dr Varghese rejected the proposition put to him in cross‑examination that sleep disorders were not a psychiatric problem, and reiterated that in cases in which sleep disorders caused behavioural problems, those problems definitely fell within the field of psychiatry. According to Dr Varghese, sleep disorders, including sleepwalking, are addressed in many psychiatric textbooks and journals (ts 244).
At the conclusion of the voir dire the trial judge ruled that Dr Varghese was qualified as a psychiatrist, and that behavioural disorders associated with dissociative states, including somnambulism, are within that field, and that he was qualified to express opinions within the limits of that expertise. He also expressed the view that the weight to be given to those opinions, having regard to Dr Varghese's lack of specialisation in sleep disorder was a question for the jury, but the issues raised with respect to his expertise did not render the evidence of Dr Varghese inadmissible (ts 249).
The ruling of the trial judge was plainly correct. The evidence given on the voir dire established that there are two related fields of expertise. The first, which is primarily the province of the psychiatrist, is the field of behavioural disorders arising from dissociative mental states, including those associated with parasomnia and somnambulism. The second, which is primarily the field of the respiratory physician, is the diagnosis and treatment of sleep disorders including sleep apnoea and other abnormal conditions associated with sleep. Dr Varghese is relevantly qualified in the former field of expertise. The fact that he was not qualified in the latter, and could not, himself, undertake the work of diagnosis and treatment undertaken by a respiratory physician, did not mean that the opinions he expressed on the mental states associated with somnambulism, and the behavioural characteristics of those who experienced sleepwalking, were not admissible. Issues arising from the existence of another field of expertise in which Dr Varghese was not qualified, or the extent of his experience in the field of sleep disorders generally, or arising from his attitude to the classification manuals available for use by medical practitioners were all questions properly taken into account by the jury when assessing the weight to be given to his evidence. However, they were not issues that went to the admissibility of his evidence.
Ground 2 should be dismissed.

The sentence appeal

The homicide laws of Western Australia were substantially amended by the Criminal Law Amendment (Homicide) Act 2008 (WA), which came into force on 1 August 2008. Because the appellant's offences were committed in April 2008 prior to the amending law coming into force, he was tried and convicted under the law applicable prior to those amendments. However, pursuant to cl 2 of sch 1 of the Criminal Code (WA), which sets out various transitional provisions relating to the amendments to the laws of homicide, although Mr Silich was convicted of wilful murder, he must be sentenced under the amended law as if he had been convicted of murder under s 279(1) of the Criminal Code (as amended). Section 279(4) of the Criminal Code now provides that a person who is guilty of murder must be sentenced to life imprisonment unless the sentence would clearly be unjust and the person is unlikely to be a threat to the safety of the community when released, in which case the person is liable to imprisonment for 20 years. It has never been suggested, nor could it be sensibly suggested, that the imposition of a sentence of life imprisonment upon the appellant would be 'clearly unjust'.
Section 90(1) of the Sentencing Act 1995 (WA) now provides that when an offender is sentenced to life imprisonment for murder, the court must set a minimum period of at least 10 years that the offender must serve before being eligible for release on parole, unless the court orders that the offender must never be released.
In Austic v The State of Western Australia [2010] WASCA 110 [153] ‑ [176], Buss JA analysed the differences between the structure of the old homicide laws, and those that are currently applicable, and the differences in the sentencing regimes applicable under each set of laws. It is unnecessary to repeat that analysis, which I respectfully adopt for the purposes of this case.
The principles that are most pertinent to the issues that arise in this case are:
(a)while, under the new regime, it will not inevitably be the case that murder committed with intent to kill will necessarily be treated as more serious, and punished more severely, than murder committed with intent to cause grievous bodily harm, the value which the community places on human life is such that it is likely that killing with an intention to cause death will be more seriously regarded: Atherden v The State of Western Australia [2010] WASCA 33 [30] ‑ [31] (Wheeler JA; McLure P and Owen JA agreeing);
(b)while the strict ranges of available non‑parole periods based upon the distinctions between wilful murder and murder, and between wilful murder carrying strict security life imprisonment and wilful murder carrying only life imprisonment have been abolished, sentencing dispositions under the previous legislative regime will generally be of assistance in determining the length of the non‑parole period to be fixed for the new offence of murder. However, there will inevitably be limitations upon the utility of such comparisons having regard to the breadth of circumstances in which murder is committed, and of those who commit murder: Austic [174] (Buss JA); The State of Western Australia v O'Kane [2011] WASCA 24 [41]; and Kowaleff v The State of Western Australia [2010] WASCA 183 [54] (Mazza J).
Under the old sentencing regime, the minimum non‑parole period that could be set in a case of wilful murder where strict security life imprisonment was not imposed was the period of 15 years, and the maximum non‑parole period was 19 years. Under the new regime, the minimum non‑parole period that may be set following a conviction of murder is 10 years, unless the court orders that the offender is never to be released, but there is no longer any maximum non‑parole period.

Sentence appeals - the principles

The principles which govern appeals against sentence are well known: Dinsdale v The Queen [2000] HCA 54; (2000) 202 CLR 321 [58] ‑ [59] (Gaudron and Gummow JJ). They are analogous to the principles which govern all appeals from the exercise of a judicial discretion. The appeal will not be allowed, and the decision disturbed merely because the appellate court would have imposed a different result if it had been called upon to exercise the discretion. Rather, the appellate court will only intervene if error is established in the exercise of the discretion. Such an error may be apparent from the reasons given for the exercise of the discretion, including the adoption of an incorrect principle, giving weight to an irrelevant consideration or failing to take a relevant consideration into account, or a mistake as to the facts. However, in some cases, even though an error of that kind is not apparent, the result of the exercise of the discretion may be so manifestly unreasonable, or plainly wrong that an inference of error can properly be drawn.

The principles applied to this case

In its ground of appeal, the State asserts that this case is of the latter kind - namely, a case in which error can be inferred from the manifest inadequacy of the sentence imposed, notwithstanding the lack of any specific error identifiable in the reasons given by the trial judge.
I agree with the proposition implicit in the position adopted by the State, namely, that a review of the observations made by the trial judge at the time of passing sentence does not reveal any error of principle, mistake of fact, the taking into account of any irrelevant consideration, or failure to take account of a relevant consideration. It follows that the only question that has to be determined is whether the minimum period which his Honour required the appellant to serve prior to becoming eligible for parole is so low as to fall outside the range of dispositions reasonably open, and therefore to manifest error. That question is to be identified by addressing the circumstances of the offences committed by the appellant, and his personal circumstances, with a view to identifying aggravating and mitigating factors, and then assessing whether the non‑parole period set by the trial judge in this case falls within the range appropriately suggested by other sentencing dispositions, taking into account the limitations upon comparisons between sentences imposed under the old and new regimes.

Aggravating factors

Following the abolition of the distinction between wilful murder and murder, it will no longer be apparent from the verdict of the jury whether the jury found that the offender had an intention to kill, or only an intention to cause grievous bodily harm at the time he or she committed the acts causing death.
Accordingly, there will be many cases in which it will be necessary for the trial judge to make a finding as to the precise intention of the offender at the time he or she committed the acts causing death because of the range of intentions which will sustain a conviction for murder under the current law. However, this is not such a case because the appellant was tried under the old law of homicide, and convicted of wilful murder on each count. Accordingly, he must be sentenced on the basis that he intended to kill each of his parents at the time he inflicted the injuries which caused their death. There are no circumstances in this case which would detract from the conclusion that the appellant's intention to kill each of his parents is a significant aggravating factor.
Another obvious and significant aggravating factor is the fact that the appellant was convicted of two offences of wilful murder. This is not one of those cases in which a single act or omission caused multiple deaths - such as where deaths are caused by the planting of a bomb or deliberately causing a motor vehicle accident. Rather, this is a case in which there was a separate and sustained attack on each of two victims, albeit in a single sequence of events. The fact that the appellant violently attacked and killed each of two people significantly aggravates the culpability of his conduct. Even though the attacks were sequential, it would be wrong in principle to equate the appellant's culpability with that of a murderer who had killed only one person: The State of Western Australia v Singh (Unreported, 1 October 2010, INS 97 of 2010).

Other significant aggravating factors include the fact that brutal and frenzied violence was directed towards two frail and elderly victims in their own home by their son; a person who they should have been able to trust. Although the evidence does not identify with precision the length of time that would have been occupied by the attacks, the number of wounds sustained by each victim, including wounds sustained when they were apparently attempting to defend themselves, suggests that the attacks must have been prolonged. The way in which the blows were delivered, being directed primarily to the upper part of the body of each deceased, supports the jury's conclusion that the blows were delivered with intent to kill.

Mitigating factors

The mitigating factors found by the trial judge were:
•the lack of planning or premeditation;
•the appellant has no prior history of violence;
•although the appellant's motive may never be known, there is no suggestion that he was motivated by base considerations like sex or greed;
•the appellant appeared remorseful;
•the appellant cooperated with police, and, although he did not plead guilty, was cooperative in the course of the trial process;
•many positive character references were proffered in support of the appellant;
•the appellant is at low risk of reoffending, particularly if he stays sober;
•although self-induced intoxication (as in this case) will seldom provide significant mitigation, in this case it is clear that the appellant formed the requisite intent while severely intoxicated due to a combination of alcohol and cannabis.
Counsel have referred the court to a number of other cases in which non‑parole periods have been set for homicide offences both before and after the changes in the legal regime to which I have referred. Because of the breadth of circumstances covered by those cases, including the circumstances of the offending and of the offender, little purpose would be served by a detailed analysis aimed at identifying aspects of each of those cases that are comparable to the present, or incomparable. It is sufficient to observe that any consideration of those cases establishes that a non‑parole period of 15 years, while not at the very bottom of the range, is very much at the lower end of the range. Prior to the amendments, it was the minimum period that could be set in any case in which an offender was convicted of wilful murder. While I accept that offenders sentenced under the new regime are not to be treated as if they were being sentenced under the old regime, dispositions made under the old regime remain relevant and provide guidance.

Having regard to the jury's finding that the appellant intended to kill each victim, that there were two victims of separate assaults, and that each victim was elderly and frail and bludgeoned to death in their own home by a family member they were entitled to trust, these homicides could not be said to be at the lower end of the range, notwithstanding the personal circumstances of the appellant and the mitigating factors found by the trial judge. The aggravating circumstances to which I have referred necessarily place these offences around the middle of the range of the homicides to which we were referred, rather than within the lower end of that range. It follows that the specification of a minimum period prior to parole which is at the lower end of the range was manifestly inadequate, and manifests error.
Giving full weight to the mitigating circumstances which I have identified, I would set aside that part of the decision of the trial judge in which he specified a minimum period required to be served prior to eligibility for parole of 15 years on each count, and in each case replace that with a minimum period of 19 years to be served prior to eligibility for parole.
BUSS JA: On 31 March 2010, Vernon Robert Silich (Mr Silich) was convicted, after a trial in the Supreme Court before McKechnie J and a jury, of the wilful murder of his mother, Faye Laraine Silich, and his father, Robert George Silich, contrary to s 278 (repealed) and s 282 (repealed) of the Criminal Code (WA).
Both offences were committed on 9 April 2008.
On 16 April 2010, the trial judge sentenced Mr Silich to life imprisonment, and set a non‑parole period of 15 years for each offence.
Mr Silich appeals to this court against his conviction.
The State appeals against the length of the non‑parole period on each count.
Mr Silich's appeal and the State's appeal were heard together. At the commencement of the hearing, counsel for Mr Silich applied for an adjournment of his appeal. The court unanimously dismissed the application. We said reasons for decision would be given later.
The background facts and circumstances are set out in the reasons of Martin CJ, with whom Hall J has expressed his agreement.

I agree with the Chief Justice that Mr Silich's appeal against conviction should be dismissed. I also agree with his Honour that the State's appeal against sentence should be allowed, and that a new non‑parole period of 19 years should be fixed for each offence.
My reasons are as follows.

Mr Silich's application for an adjournment

The court's power to grant an adjournment to an offender who is appealing against conviction is broad and flexible. The purpose of the power is to enable the court to achieve justice in the particular case. This is not, of course, confined to justice from the offender's perspective. There is a public interest in the prompt disposition of proceedings on appeal. However, the overriding consideration is whether an adjournment is necessary to ensure that the offender is given a reasonable opportunity properly to present his or her case on appeal. This is fundamental to the proper administration of justice in the criminal jurisdiction. Compare, in the different context of an application by an accused for the adjournment of a criminal trial, the observations of Hunt CJ at CL, Grove and Dunford JJ in Alexandroaia v The Queen (1995) 81 A Crim R 286, 289 and Gummow J in HG v The Queen [1999] HCA 2; (1999) 197 CLR 414 [126].
In general, four factors of relevance in determining whether to grant an application for an adjournment by an offender who is appealing against conviction are these. First, the nature and extent of the delay if the adjournment is granted. Secondly, the reasons for the adjournment. Thirdly, the prejudice (if any) to the offender if the adjournment is not granted. Fourthly, the prejudice (if any) to the State or the public interest if the adjournment is granted. This is not intended to be an exhaustive statement. In a particular case, there may be other factors.
Although the court's discretion is broad and flexible, the offender must establish a proper basis for its exercise. The court will, in general, require cogent reasons before granting an adjournment.
In the present case, at the commencement of the trial, Mr Silich made formal admissions pursuant to s 32 of the Evidence Act 1906 (WA) as to:
(a)the identity of the deceased; and
(b)the fact that the deceased died as a result of injuries he inflicted (ts 9).
It was not in contest that Mr Silich had, in fact, killed his parents by kicking them to death in the bedroom of their home while he was wearing steel‑capped boots.
The State's case at trial was, in essence, this:
(a)On the evening of 8 April 2008, Mr Silich visited his parents at their home at 102 Virgil Avenue, Yokine. He had dinner with them. The history of Mr Silich's relationship with his parents was close and loving.
(b)During the course of the evening, Mr Silich and his father consumed a significant quantity of alcohol. Mr Silich also consumed some cannabis.
(c)Sometime after 11.30 pm on 8 April 2008, something upset Mr Silich.
(d)At this time, Mr Silich entered his parents' bedroom and kicked them to death.
(e)Mr Silich was extremely affected by alcohol at the time of the incident, but was not so affected as to be incapable of forming an intention. He entered his parents' bedroom, overpowered them and struck the deliberate, repeated blows that caused their deaths.
(f)The blows were directed primarily towards the head and upper body of each deceased.
(g)The only reasonable inference in these circumstances was that the kicks were accompanied by an intention to kill.
(h)After the incident, Mr Silich was capable of placing one of his father's hands over one of his mother's hands, and telephoning his friend, Michael Jurotte, for assistance, rather than the police. He was also able to arrange for his rent to be paid.
(i)Mr Silich was acting voluntarily.
The defence case was that, at the material time, Mr Silich was sleepwalking and, as a result, he was absolved from criminal responsibility for the death of his parents. Alternatively, the defence case was that, at the material time, Mr Silich was so intoxicated as to be unable to form the intent necessary for a conviction of either wilful murder or murder and, in consequence, he should be convicted of manslaughter.
Mr Silich gave and called evidence in his own defence. He said that on the night in question he went to sleep at his parents' home. Later, he awoke and found his parents, lying on the floor, dead. He was unable to recall the incident in question or perpetrating the acts which caused their deaths (ts 311 ‑ 312).
Accordingly, the primary issues at the trial were whether Mr Silich's actions were voluntary and, if so, his intention at the time he inflicted the injuries upon the deceased.
A significant part of the defence case at the trial relied on expert evidence. Counsel for Mr Silich called Professor Jason White, a pharmacologist, Dr Jack Philpott, a respiratory physician, and Dr Victoria Pascu, a forensic consultant psychiatrist.
Professor White and Dr Pascu gave evidence as to the effect that Mr Silich's blood alcohol concentration at the material time might have had on his capacity to form an intention to kill or cause grievous bodily harm to the deceased.
Dr Philpott gave evidence, based on Mr Silich's history and a sleep study undertaken with him on 24 October 2009, to the effect that the incident in question was consistent with an episode of violent somnambulism (or sleepwalking).
The State called Dr Francis Varghese, an associate professor of psychiatry and a senior consultant psychiatrist, to give evidence about sleepwalking.
At the hearing of the appeal, counsel for Mr Silich relied, in support of the application for an adjournment, on an affidavit of Mr Silich sworn 4 February 2011. In the affidavit, Mr Silich deposes, relevantly:
4.On 21 December 2010, I observed a television programme which aired on SBS at 7:30 pm, entitled 'The Problem with Sleepwalking', which concerned the issue of sleeping as a cause of motiveless homicide.
5.On 29 December [2010], I observed a television programme which aired on ABC 2 at 11:00 pm entitled 'The Secret Lives of Sleepwalkers', which dealt with similar material to the earlier programme.
6.Having viewed the programmes, I verily believe that there may be available evidence in relation to the question of sleepwalking that may cast doubt on my conviction, which was previously unknown to myself, my solicitors or my medical advisors.
7.The programmes outlined a number of cases strikingly similar to my own, which involved the killing of my parents without motive, and contained interviews with prominent medical specialists in sleepwalking.
8.Dr Jack Philpott, who gave evidence on behalf of the defence at my trial, is an expert in the medical science in Australia in relation to sleepwalking.
9.It now appears that the science of the analysis of sleepwalking may be more advanced in Europe and America than either I or my solicitors had previously known. I am now anxious to have my solicitors contact a number of medical experts in Europe and America to have them examine my medical data and the transcript of my trial to ascertain whether there is any scientific evidence which may shed light on the circumstances of my parents' death in medical or scientific terms.
10.On 24 October 2009, at Sir Charles [Gairdner] Hospital, Dr [Philpott] conducted some tests on me, which were indicative of a sleepwalking disorder, but not conclusive. I am anxious that the European experts have an opportunity to assess this data, in light of the current expertise to see whether there is any further relevant and probative material which might have been put before the jury at my trial, had it [been] known.
11.As soon as I saw the SBS programme, I instructed my solicitors to locate the experts in question. I was advised by my solicitors that there would be insufficient time to locate and brief an expert in respect of my matter before the hearing of the appeal. I was also advised that it would be likely to be a costly exercise.
12.My finance position has this week received a boost with the dismissal of drugs charges in the Magistrates Court on 2 February 2011, which led to the freeing up of assets previously frozen under proceeds of crime legislation. This will make available to me a not insignificant sum which my solicitors will be able to use to locate and brief the European experts.
13.In the event that any fresh material is forthcoming as a result of analysis of my case by European and American experts, I would propose that a fresh ground of appeal be added to my existing grounds of appeal, relating to the proposed fresh evidence.
14.I am accordingly seeking an adjournment of my appeal for six months, in order for my solicitors to make these enquiries and if appropriate make the necessary amendments and additions to the existing grounds of appeal.
No other evidence was adduced before this court in relation to the television programmes referred to in Mr Silich's affidavit or otherwise in support of the application for an adjournment. Recordings of the programmes were not tendered.
At common law, there is, of course, a well-established distinction between new evidence, on the one hand, and fresh evidence, on the other. New evidence is evidence that could, with reasonable diligence, have been obtained or discovered for use at the trial. Fresh evidence is evidence which either did not exist as at the date of the trial or could not, with reasonable diligence, have been obtained or discovered for use at the trial. See Beamish v The Queen [2005] WASCA 62 [9].
In Lawless v The Queen [1979] HCA 49; (1979) 142 CLR 659, Mason J said, in relation to new evidence:
However, it is not permissible for a court of criminal appeal to set aside a conviction if the newly adduced evidence, not being fresh evidence strictly so called, reveals no more than a likelihood that the jury would have returned a verdict of not guilty. Two considerations operate to bring about this result. The first is that in a criminal trial the accused is entitled to decide how his case will be conducted, in particular, what evidence he will call. He makes this decision in the light of the knowledge that he is tried but once, unless error or miscarriage of justice results in a successful appeal. He cannot therefore conduct his defence by keeping certain evidence back in the expectation that, if he is convicted, the existence of the uncalled evidence will provide a ground for a second trial at which a different or refurbished defence may be presented. Accordingly, an accused person, if convicted, generally cannot complain of a miscarriage of justice if he deliberately chooses not to call material evidence, it being actually available to him at the time of the trial, or if he fails to exercise reasonable diligence in seeking out material evidence.
The second consideration is that there must be powerful reasons for disturbing a conviction obtained after a trial which has been regularly conducted … If the evidence newly adduced falls short of establishing that the accused should not have been convicted, there is no overwhelming reason why the conviction, regularly obtained after a fair trial should not be allowed to stand (675 ‑ 676).
In Mickelberg v The Queen [1989] HCA 35; (1989) 167 CLR 259, Mason CJ expressed the test to be applied by an appellate court, in deciding whether to set aside a conviction on the ground of fresh evidence, as follows:
It is established that the proper question is whether the court considers that there is a significant possibility that the jury, acting reasonably, would have acquitted the appellant had the fresh evidence been before it at the trial. This test was endorsed by four of the five Justices in Gallagher v The Queen ((1986) 160 CLR 392). Deane J and I (at 402) considered that the test was best expressed in those terms. Gibbs CJ (at 399) expressed his substantial agreement with the statement, although his Honour emphasised that 'no form of words should be regarded as an incantation that will resolve the difficulties of every case'. Dawson J said (at 421) that the court would need to conclude that 'a jury might entertain a reasonable doubt about the guilt of the appellant'. His Honour went on to say (at 421) that in his view the use of the expression 'significant possibility' did not involve a different standard. I am in agreement with those statements (273).
The approach of an appellate court to the consideration of fresh evidence will be different if the appellant submits that a conviction should be set aside outright (and there should not merely be a retrial) in that innocence is shown, or the existence of an appropriate doubt established. See Ratten v The Queen [1974] HCA 35; (1974) 131 CLR 510, 518 ‑ 519 (Barwick CJ), and the examination of the relevant issues by Steytler J in Easterday v The Queen [2003] WASCA 69; (2003) 143 A Crim R 154 [207] - [211].
In Rinaldi v The State of Western Australia [2007] WASCA 53, Steytler P (Wheeler and Pullin JJA agreeing) reviewed the authorities concerning the admissibility at common law of new and fresh evidence on appeal, and said [81] ‑ [82]:
It has been suggested that the distinction between fresh and new evidence is not as significant as it once was: see, for example, Nolan v The Queen, unreported; CCA SCt of WA; Library No 970260; 22 May 1997, per Malcolm CJ with whom Pidgeon and Murray JJ were in agreement. However, as this Court has noted in Easterday v The Queen (2003) 143 A Crim R 154 at [204] and in Beamish at [13], the distinction is one which is soundly based in principle and which continues to be recognised, even though there may be somewhat greater latitude in the case of criminal trials than in the case of civil trials: see Ratten v The Queen (1974) 131 CLR 510 at 517; Mickelberg (High Court) at 301; De La Espriella-Velasco v The Queen (2006) 31 WAR 291 at [150] ‑ [153].
Where the evidence is fresh, the test appears to be whether there is a significant possibility that, in the light of all of the admissible evidence (including that given at the trial), a jury, acting reasonably, would have acquitted the accused: see Gallagher, at 399, 402 and 421; Mickelberg, at 273, 275 and 302; Beamish at [14].
I agree, with respect, with his Honour's observations.
Section 39(1) of the Criminal Appeals Act2004 (WA) provides that an appeal court must decide an appeal on the evidence and material that were before the lower court. By s 39(3), however, s 39(1) does not affect the power of an appeal court to admit evidence pursuant to s 40 of the Act. Section 40(1) provides, relevantly:
For the purposes of dealing with an appeal, an appeal court may do any or all of the following ‑
(a)order the production of any record or thing, whether or not an exhibit, that is or may be relevant to the appeal;
(b)order a witness who would have been compellable at the trial in the lower court, whether or not called at the trial, to attend and be examined before the appeal court;
…
(d)subject to the Evidence Act 1906 section 9, admit the evidence of a witness, including a convicted appellant, who is a competent but not compellable witness;
(e)admit any other evidence.

In Rinaldi, Steytler P said, in relation to s 40(1)(a), (b), (d) and (e):
While these provisions afford the Court a discretion, which is not expressed to be limited in any way, to do any of the things provided for, it is most improbable that the legislature intended that they 'should be construed in a way that would have the practical effect of obliterating the distinction between original and appellate jurisdiction': CDJ v VAJ (1998) 197 CLR 172 at [111] per McHugh, Gummow and Callinan JJ (dealing with the provisions of s 93A(2) of the Family Law Act 1975 (Cth)) and see also De La Espriella-Velasco at [150] per Pullin JA. The common law principles have, of course, been developed over many years in order to meet the ends of justice and the considerations giving rise to them will plainly be material to the exercise of the statutory discretion, which must be exercised judicially. While the common law principles touching upon the distinction between new and fresh evidence are not necessarily determinative of the manner of exercise of the statutory discretion, the considerations giving rise to those principles will ordinarily be weighty, so much so that it will be a rare case in which an exercise of the statutory discretion produces a different outcome to that produced by application of the common law principles [84].
I refused Mr Silich's application for an adjournment for the following reasons.
First, Mr Silich bears the burden of proving that the evidence referred to in his affidavit is fresh as distinct from new. He will not prove that the evidence is fresh unless he satisfies this court, on the material before it, that the evidence either did not exist as at the date of the trial or could not, with reasonable diligence, have been obtained or discovered for use at the trial. Mr Silich was represented at the trial by the senior counsel and the solicitors who act for him on the appeal. Also, as I have mentioned, at the trial, his counsel called expert evidence from Dr Philpott to the effect that the incident in question was consistent with an episode of violent somnambulism. It is a remarkable feature of the application for an adjournment that no affidavit of Dr Philpott or any of Mr Silich's legal representatives was filed on his behalf. If the evidence referred to in Mr Silich's affidavit was relevant to and probative of his defence of involuntariness, and the evidence in question either did not exist as at the date of the trial or could not, with reasonable diligence, have been obtained or discovered for use at the trial, it is reasonably to be expected that affidavits to that effect of Dr Philpott (or another Australian expert in somnambulism) and a legal representative of Mr Silich would have been filed. No satisfactory explanation has been given for the absence of these affidavits. In the circumstances, the only inference reasonably open on the material before this court is that the evidence referred to in Mr Silich's affidavit is new as distinct from fresh.
Secondly, the new evidence referred to in Mr Silich's affidavit will not demonstrate a miscarriage of justice that requires the appeal to be allowed unless the evidence in question establishes that he should not have been convicted. On the material before this court, Mr Silich does not have a reasonable prospect of demonstrating, by reference to the new evidence, that he should not have been convicted. In any event, even if the evidence referred to in Mr Silich's affidavit is fresh as distinct from new, the material before this court does not reveal that Mr Silich has a reasonable prospect of demonstrating, by reference to that evidence, that there is a significant possibility that the jury, acting reasonably, would have acquitted him had the evidence in question been before it at the trial.
Thirdly, Mr Silich's statement in his affidavit that he believes 'there may be available evidence in relation to the question of sleepwalking that may cast doubt on my conviction, which was previously unknown to myself, my solicitors or my medical advisers' [6], is unsupported by any source or grounds, except his own view about the content and significance of the television programmes. Mr Silich left school after completing Year 10. He obtained a certificate in 'auto trade studies'. Mr Silich worked as a taxi driver (and, occasionally, a truck driver) for about 22 years before he was charged with the wilful murder of his parents (ts 294). He has no education or training that would enable him to express an admissible opinion or statement of belief of the kind to which I have referred. There are no particulars before this court as to the content of the television programmes, and no admissible evidence as to whether that content was known or unknown, as at the date of the trial, by his solicitors and medical advisers.
Fourthly, Mr Silich's statement in his affidavit that it 'now appears that the science of the analysis of sleepwalking may be more advanced in Europe and America than either I or my solicitors had previously known' [9], is also unsupported by any source or grounds, except his own view about the programmes. This statement has the same deficiencies as the statement which I have analysed at [136] above.
Fifthly, it is entirely speculative that any enquiries which might be made of any experts on somnambulism in Europe or the United States would produce any information or opinion, relevant to and probative of Mr Silich's defence of involuntariness, that was not given by Dr Philpott in his evidence at the trial. No experts in Europe or the United States have been identified.
Sixthly, there is no material before this court which indicates that any effort or attempt was made by Mr Silich or his legal representatives between 29 December 2010 (when the second television programme was broadcast) and 14 February 2011 (when the application for an adjournment was made) to contact Dr Philpott or another Australian expert on somnambulism and obtain their advice in relation to the content of the programmes.
Seventhly, there is no material before this court (apart from Mr Silich's unsupported, inexpert and inadmissible statements of belief) which establishes that medical expertise in Australia in relation to somnambulism is less advanced or sophisticated than the medical expertise on this subject in Europe or the United States.
Accordingly, Mr Silich has not made out a proper basis for the exercise by this court of its discretion to grant an adjournment. He has had a reasonable opportunity properly to present his case on appeal. These are the critical considerations, and they decisively outweigh the absence of any specific prejudice (and the existence of only modest general prejudice) to the State and the public interest if an adjournment of about six months were to be granted. The achievement of justice in Mr Silich's appeal does not require an adjournment of the hearing.

Mr Silich's appeal against conviction: ground 1: general

Ground 1 of Mr Silich's appeal against conviction alleges that the trial judge erred in law by ruling that Mr Silich's video‑recorded interview with police was admissible.
Mr Silich's interview with the police commenced at 2.22 pm on 9 April 2008. A blood sample taken from him at 12.56 pm on that date disclosed a blood alcohol concentration of 0.138%.
The trial judge conducted a voir dire for the purpose of determining defence counsel's objection to the admissibility of Mr Silich's video‑recorded interview.
At the voir dire, the evidence before his Honour included a report from Professor White which said that, on the basis of the blood alcohol concentration of 0.138% as at 12.56 pm on 9 April 2008, Mr Silich's blood alcohol concentration at about 3.45 am on that date would have been about 0.276%, with a possible range of 0.23% to 0.322%.
Professor White's report noted that the average rate of elimination of alcohol from the body is about 0.015% per hour. At this rate, Mr Silich's blood alcohol concentration at about 2.22 pm on 9 April 2008 would have been about 0.116%.
The precise time at which Mr Silich killed his parents was unknown, but at about 3.45 am Mr Silich telephoned Mr Jurotte from his parents' home and asked him to come to their house. Mr Jurotte arrived a few minutes later and, after a brief conversation with Mr Silich, found the bodies of the deceased.
Defence counsel submitted to the trial judge that the video‑recorded interview should not be admitted into evidence in that:
(a)admissions made by Mr Silich during the interview were not made voluntarily;
(b)alternatively, even if the admissions were made voluntarily, they were not reliable;
(c)alternatively, even if the admissions were made voluntarily and were reliable, it would be unfair to Mr Silich to admit them.
His Honour ruled that the video‑recorded interview was admissible. He said:
I consider that the video record is admissible and I see no reason to exclude it in the exercise of discretion. There is an issue about the amount of alcohol that the accused had taken and the extent to which he was under the influence at the time and the police officers did not ask him, as normally happens, whether he was fit but I have observed the video twice and consider that the questions he answered were voluntary and the reliability is not such that comes off the page to exclude it in the exercise of discretion. So the video is admissible (pre‑trial ts 150).
Before this court, counsel for Mr Silich reiterated, in substance, the submissions made to the trial judge.

Mr Silich's appeal against conviction: ground 1: voluntariness

It is a fundamental requirement of the common law that a confessional statement must be voluntary. See R v Swaffield [1998] HCA 1; (1998) 192 CLR 159 [50] (Toohey, Gaudron & Gummow JJ).
As Deane J noted in Cleland v The Queen [1982] HCA 67; (1982) 151 CLR 1, the rational basis for the rule excluding confessions that are not voluntary is a combination of the potential unreliability of a confessional statement that is involuntary and the common law privilege against self‑incrimination (18).
It is presumed that a confession is voluntary if there is nothing to suggest that it is involuntary. See Hough v Ah Sam [1912] HCA 78; (1912) 15 CLR 452, 457 (Barton J). If the issue of voluntariness is raised, the State or the Crown bears the onus of establishing, on the balance of probabilities, that the confession is voluntary. See Wendo v The Queen [1963] HCA 19; (1963) 109 CLR 559, 572 ‑ 573 (Taylor & Owen JJ).
A confession made by an accused 'more or less under the influence of intoxicating liquor is not inadmissible as evidence unless the degree of intoxication is so great as to deprive him of understanding what he was confessing': Sinclair v The King [1946] HCA 55; (1946) 73 CLR 316, 336 (Dixon J).
Where an accused is intoxicated, to some extent, a confession will not be voluntary unless the evidence demonstrates that, on the balance of probabilities, the accused was capable of appreciating that he or she had a free choice as to whether to speak or remain silent and was capable of exercising sufficient volition to give effect to what he or she knew was this right. See R v Buchanan [1966] VR 9, 15 (Sholl J, Pape J agreeing); R v Smith (1992) 58 SASR 491, 498 (Perry J).
The effects of alcoholic liquor vary, to a very significant extent, from person to person. Questions of fact and degree will arise in determining whether a confession made by an accused who is intoxicated, to some extent, was voluntary. See R v Ostojic (1978) 18 SASR 188, 196 ‑ 197 (Wells J, Hogarth & King JJ agreeing).
In the present case, the critical question for the trial judge, on the issue of voluntariness, was this: whether the State had established on the balance of probabilities that, despite his partial intoxication, when Mr Silich was interviewed by the police he was capable of:
(a)appreciating that he had a choice to speak or remain silent, and was capable of exercising sufficient volition to give effect to what he knew was this right; and
(b)understanding the questions put to him and what he was confessing.
In my opinion, his Honour, with respect, correctly concluded that the admissions against interest made by Mr Silich in the course of the interview were voluntary and the interview was therefore admissible. My reasons are as follows.
Shortly after the commencement of the interview, Acting Detective Sergeant Darren Bethell cautioned Mr Silich. The following exchange occurred:
Q. … Now, before I question you in relation to that I'm going to caution you and I need you to listen in. You're not obliged to say or do anything unless you wish to do so.
A. All right.
Q. Anything you do say will be recorded and may be used as evidence.
A. Yeah.
Q. Okay. Now, I need to be sure that you understand what your rights are so can you explain to me what you understand that I've just explained to you.
A. Anything that I say can be used against me and, ah, yeah.
Q. Okay. And you're aware obviously you don't have to answer my questions if you don't want to.
A. Yeah.
Q. Okay. And you may wish to answer some questions and not others. That's your right. Okay. You also have a right to legal counsel if you so, if you so wish. Right. Just let us know and so you understand those rights?
A. Yeah.
Q. That I've explained to you. Okay. You happy to proceed?
A. Yeah (interview ts 2 ‑ 3).
I have watched the video‑recorded interview. Mr Silich evinced a capacity to understand his surroundings, and the time, place and significance of the interview. He appeared to appreciate the nature and content of the caution. During the interview he chose to answer some questions and he declined to answer others. Mr Silich appeared to have no difficulty in understanding the questions put to him. He gave coherent answers to those questions he chose to answer.
There was no evidence as to the likely impact of a blood alcohol concentration of 0.116% on Mr Silich's cognitive functioning.
Mr Silich's mental acuity during the interview is demonstrated by his facetious response to a question, towards the end of the interview, as to whether any promises or threats had been made to him:
Q. Okay. Have you got any complaints about the way you have been treated by police since you have been with us today?
A. No, and you actually smoke the same brand that I smoke so ‑ ‑ ‑
Q. Okay. You have been coherent, you have understood everything that has happened with us today?
A. Yes.
Q. Okay. This interview has been made voluntarily by yourself, there's been no promises or threats made to you?
A. Not yet.
Q. No? Okay.
A. No.
Q. There's been no inducements to consenting to this.
A. No (interview ts 22).
None of Mr Silich's answers was rambling or unintelligible. The substantial majority of his answers accorded with the undisputed facts or the accounts of other witnesses.
It is true that Mr Silich did provide some wrong answers. In particular, although it was not in contest that Mr Silich resided at 7 Kweda Way, Nollamara (and had done so for many years), he said towards the beginning of the interview that:
(a)his address was 102 Virgil Avenue, Yokine (that is, his parents' home) (interview ts 2);
(b)he had been living there 'a while' and, indeed, had lived there all his life (interview ts 3); and
(c)he denied that he had lived elsewhere recently (interview ts 4).
Mr Silich, in his evidence‑in‑chief at the trial, sought to explain the wrong answers, as follows:
I think you gave your address to the police---I did.
When they asked you, what did you give them---It was a mistake. I gave my parents' address, [102] Virgil Avenue, Yokine. It's an address that - I've always used that address from my licence and for - you know, any paperwork, I've always used that as an address. I've had a post box in Morley since '91 and all my mail pretty much goes to the post box and it was ‑ it was just a mistake that I'd made.
What would you say to the proposition you were trying to actively mislead or deceive the police in giving that address---No. No, that's not the case (ts 319).
When a search warrant was executed at Mr Silich's residence in Nollamara, police found prohibited drugs. Charges were brought against him and an application for the confiscation of his property was made. It is possible that the wrong answers were given with a view to avoiding the detection of the drugs. However, this possibility was not explored by the prosecutor in his cross‑examination of Mr Silich at the trial.
In any event, I am satisfied that, despite the wrong answers, the only reasonable conclusion open, on an evaluation of the video‑recorded interview and the other evidence before the trial judge at the voir dire, is that the State established, on the balance of probabilities, that despite his partial intoxication, when Mr Silich was interviewed by the police he was capable of:
(a)appreciating that he had a choice to speak or remain silent, and was capable of exercising sufficient volition to give effect to what he knew was this right; and
(b)understanding the questions put to him and what he was confessing.

Mr Silich's appeal against conviction: ground 1: the unfairness discretion

A trial judge has a discretion to exclude an accused's voluntary confession if it would be unfair to the accused to admit the confession in evidence. The purpose of this discretion is to protect the rights and privileges of the accused, including his or her procedural rights. See Swaffield [52], [78].
In Swaffield, Toohey, Gaudron and Gummow JJ observed that 'it is not always possible to treat voluntariness, reliability, unfairness to the accused and public policy considerations as discrete issues' [74]. Their Honours added:
The overlapping nature of the unfairness discretion and the policy discretion can be discerned in Cleland v The Queen ((1982) 151 CLR 1. See also Foster v The Queen (1993) 67 ALJR 550; 113 ALR 1). It was held in that case that where a voluntary confession was procured by improper conduct on the part of law enforcement officers, the trial judge should consider whether the statement should be excluded either on the ground that it would be unfair to the accused to allow it to be admitted or because, on balance, relevant considerations of public policy require that it be excluded. That overlapping is also to be discerned in the rationale for the rejection of involuntary statements. It is said that they are inadmissible not because the law presumes them to be untrue, but because of the danger that they might be unreliable (See Sinclair v The King (1946) 73 CLR 316 at 335, per Dixon J, referring to R v Warickshall (1783) 1 Leach 263 [168 ER 234] and R v Baldry (1852) 2 Den 430 at 445 [169 ER 568 at 574]. See also Cleland v The Queen (1982) 151 CLR 1 at 27 ‑ 28; R v Scott (1856) 1 Dears & Bell 47 at 58 [169 ER 909 at 913-914]). That rationale trenches on considerations of fairness to the accused. And if admissibility did not depend on voluntariness, policy considerations would justify the exclusion of confessional statements procured by violence and other abuses of power [74].
Although unreliability is an important aspect of the unfairness discretion, it is not exclusive. See Swaffield [78]. As I have mentioned, the purpose of the discretion is to protect the accused's rights and privileges. It may be, in a particular case, that, because of some impropriety, the accused would be disadvantaged in the conduct of his or her defence if a confessional statement were to be admitted. See Swaffield [78].
An accused who asserts that a voluntary confession was improperly or unfairly obtained bears the onus of proving facts that would justify an exercise of the discretion in his or her favour. See Wendo (565); MacPherson v The Queen [1981] HCA 46; (1981) 147 CLR 512, 519 ‑ 520 (Gibbs CJ & Wilson J).

In the present case, the trial judge's discretion to exclude the video‑recorded interview was exercisable by reference to the reliability of what Mr Silich had said against his own interest, the free exercise by him of his right to speak or remain silent, and the propriety of the police investigation and their treatment of Mr Silich.
Mr Silich chose not to give evidence at the voir dire. At the trial, he said in evidence that he regretted participating in the interview (ts 341). Mr Silich did not say, however, that he did not understand his rights, or the implications of participating in the interview, or any of the questions put to him (ts 319, 342).
It is apparent from the video‑recorded interview (interview ts 21), and from the evidence of Detective Sergeant Bethell (ts 102) and Mr Silich (ts 318, 340) at the trial, that Mr Silich was in police custody from about 4.45 am on 9 April 2008. Before the interview commenced, Mr Silich slept in one of the cells at the police station, had a 'couple of coffees', was offered food (which he declined because he was not hungry) and was permitted to smoke a cigarette.
Mr Silich accepted in evidence at the trial that the police had asked him whether he wanted a lawyer. He did not retain a lawyer because he 'never had the need for one' (ts 319).
I am not persuaded that there was any unreliability in Mr Silich's admissions against interest, in the course of the interview, as a result of his partial intoxication. As I have mentioned, the substantial majority of his answers accorded with the undisputed facts or the accounts of other witnesses.
There is no reasonable basis for impugning the propriety of the police investigation, or their treatment of Mr Silich, or the manner and circumstances in which they conducted the interview. In particular, there was no breach of Mr Silich's right to choose whether to speak to the police or to remain silent. I am satisfied that Mr Silich understood the nature and content of the caution. As I have mentioned, during the interview he chose to answer some questions and he declined to answer others. The extent of Mr Silich's intoxication did not affect his capacity to make an informed decision as to whether he should participate in the interview.
The admission of the interview, in the circumstances in which it occurred, did not jeopardise Mr Silich's right to a fair trial.
Mr Silich has not alleged that the trial judge's decision‑making was vitiated by an express error. He has not demonstrated that his Honour's refusal to exercise the discretion in his favour was unreasonable or plainly unjust. See House v The King [1936] HCA 40; (1936) 55 CLR 499, 504 ‑ 505 (Dixon, Evatt & McTiernan JJ).

Mr Silich's appeal against conviction: ground 1: conclusion

Ground 1 is without merit. I would refuse leave to appeal on this ground.

Mr Silich's appeal against conviction: ground 2

I agree with Martin CJ, for the reasons he gives, that ground 2 of Mr Silich's appeal against conviction fails.
I merely note that the issue of involuntariness or non‑insane automatism during sleepwalking, in the context of the common law, was considered by the English Court of Appeal in R v Burgess [1991] 2 QB 92 and the Supreme Court of Canada in R v Parks [1992] 2 SCR 871.
In Burgess, the appellant was convicted after a trial on a count of wounding with intent to do grievous bodily harm. His defence was that he lacked the necessary intent in that, during undisputed violence against the victim, he was sleepwalking and suffering from non‑insane automatism. The prosecution and the defence called expert medical evidence. The defence called a consultant forensic psychiatrist, a consultant psychiatrist and a consultant neuro‑psychiatrist to give evidence about somnambulism (94).
In Parks, the appellant was convicted, after a trial, of murder. His defence was that he was in a state of somnambulism at the time of the killing and, in consequence, he was entitled to be acquitted on the basis of non‑insane automatism. A large part of the defence case was based on

medical evidence. The defence called a neurophysiologist and specialist in sleep and sleep disorders, a neurologist, a psychiatrist, a forensic psychiatrist and, finally, a neurologist and psychiatrist to give evidence concerning somnambulism.

The State's appeal against sentence

I agree with Martin CJ, for the reasons he gives, that the State's appeal against sentence should be allowed. I also agree with the orders his Honour proposes in relation to this appeal.
HALL J: I agree with the Chief Justice.