HKSAR v. LIU CHUN YIP

CACC 266/2005

IN THE HIGH COURT OF THE

HONG KONG SPECIAL ADMINISTRATIVE REGION

COURT OF APPEAL

criminal APPEAL NO. 266 OF 2005

(ON APPEAL FROM HCCC NO. 120 of 2003)

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J U D G M E N T

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Stuart-Moore, VP (giving the judgment of the Court):

Background

1.  On 29 August 2002, the appellant killed Chui Sau-chun (Chui) and Tsoi Wai-man and he badly wounded two other members of the same family using a large kitchen knife to stab them all.  These motiveless attacks were apparently committed while the appellant was suffering from a psychotic episode.  The appellant was Chui’s godson.  He had been living for just over a month with her family, as a favour to him, in their ground floor flat in Sheung Wan where the attacks took place.

2.  Originally, the prosecution had been prepared to accept, on the two counts of murder, the pleas of guilty to manslaughter which were offered by the defence on the ground of diminished responsibility and to have the two other counts of wounding with intent left on the file.  The propriety of accepting pleas of guilty to manslaughter was considered by Beeson J in front of whom the case was first listed.  In the light of the psychiatric evidence with which she was provided, the judge ruled that these pleas should not be accepted and that the trial should proceed on the murder counts.

3.  Ultimately, the case was tried by Lunn J and a jury.  There was no issue at trial that the appellant had carried out the attacks.  On arraignment, the appellant pleaded guilty to manslaughter in respect of counts 1 and 2 and to unlawful and malicious wounding on counts 3 and 4.  These pleas, in the light of the earlier ruling by Beeson J and, we were informed, a further ruling by Lunn J, were not accepted by the prosecution.  The appellant was ultimately convicted on the two counts of murder as well as the two counts of wounding with intent.

4.  The appellant sought leave to appeal against conviction.  In due course, Mr Paul Loughran, who did not appear in the court below, was instructed to act on the appellant’s behalf.  Thereafter, the amended perfected ground of appeal, which replaced all previous grounds, was that:

“The learned Trial Judge(s) erred in law and/or fact by wrongly ruling and/or directing that if the abnormality of mind was related to the abuse of drugs it was not capable of satisfying the relevant criteria in s3 [of the] Homicide Ordinance, Cap. 334 of (induction by) ‘disease or injury’, and [was] thus incapable of making out the defence of diminished responsibility allowed for by such section.”

5.  This ground raises a point of some importance and we indicated to counsel that leave to appeal would be given.  The hearing then proceeded as the appeal.

6.  There was no issue at trial that the appellant, at the time he killed the victims, was suffering from an abnormality of mind which had been induced by paranoid psychosis, a disease of the mind.  There was agreement also that the appellant’s abnormality of mind substantially impaired his mental responsibility for his acts at the time of the killings.  The only area of real dispute, which arose from the evidence given by the psychiatrists, was the actual cause of the appellant’s disease of the mind.  The prosecution’s psychiatrist gave an opinion that this was the result of the appellant’s abuse of dangerous drugs over many years whereas the defence psychiatrist took the view that there were other factors which had led to the appellant’s psychotic condition.

7.  In addition to the psychiatric evidence, there was uncontradicted evidence at trial, based on the scientific analysis of samples taken from the appellant after his arrest, that the appellant was not intoxicated by the effects of dangerous drugs at the time of the killings.  The significance of the disagreement between the psychiatrists as to what may have caused the appellant’s psychosis was that the jury were directed that if the abnormality of mind stemming from paranoid psychosis was “induced by abuse of dangerous drugs including ‘ice’ and ‘ecstasy’”, this would fall outside the terms of the definition of diminished responsibility in section 3(1) of the Homicide Ordinance and, in those circumstances, such a defence to the charges of murder must fail.

8.  The guilty verdicts provide a clear indication that the jury was satisfied that the abnormality of mind was induced by the appellant’s long-term abuse of dangerous drugs.  The issue on which this appeal has focused, therefore, has been whether the fact that the disease of (or injury to) the mind was caused by prolonged abuse of dangerous drugs prevented the appellant from putting forward a defence of diminished responsibility on this basis.  If so, the appeal must succeed as the appellant was not permitted to advance a defence of diminished responsibility on this evidential foundation.

9.  There was, however, an alternative basis on which the defence of diminished responsibility was allowed, and rightly so, to be put forward to the murder counts.  This arose from the evidence given by the defence psychiatrist whose opinion was that the disease of the mind was not the result of drug abuse but had resulted from other factors.  Plainly, from the verdicts returned by the jury, this was, as we have indicated, rejected so that this alternative route for arriving at diminished responsibility verdicts has no relevance to this appeal other than to explain how a defence of diminished responsibility was before the jury at all.

The facts

10.  The flat at Sheung Wan where the appellant had been staying was occupied by six others apart from himself.  The appellant had the use of the cockloft.  Chui shared a bedroom with her granddaughter, Chan Ka-man.  Chui’s son, Chan Che-chow, shared a bedroom with his girlfriend, Yeung Mei-kuen.  The third bedroom was shared by Chan Che-chow’s son, Chan Hei-ming, and his girlfriend, Tsoi Wai-man.  Chan Hei-ming had left for work at the time of the attacks.

11.  At some time shortly before the arrival of the police at 9.36 am on 29 August 2002, Chan Che-chow, whose room had been locked, heard his mother screaming for help and he ran to her assistance.  As he went into his mother’s room, he found the appellant clasping a knife in both hands and stabbing his mother and his daughter.  As Chan Che-chow bravely fought the appellant, he sustained several serious wounds.  Fortunately, despite her terrible injuries, Chan Ka-man was able to alert the police by telephone.  When they arrived, Chan Che-chow was still struggling with the appellant on the floor.

12.  The evidence given by pathologists about the injuries sustained by the two victims who died showed that these consisted mainly of deep stab wounds in the region of the chest.  As a result of the serious wounds received by Chan Ka-man, she required about four months in-patient treatment.  Her father, Chan Che-chow, remained in hospital for about a fortnight.

13.  The appellant was also taken to hospital, arriving at 10.46 am.  He was spoken to by a doctor but he said nothing and was given no medication.  He was seen later by another doctor who found him to be “confused”, but the appellant said that was not under the influence of alcohol or drugs and that he had no history of psychiatric problems.  Later in the day, the appellant was seen by Dr Koh, a psychiatrist at the hospital, who learnt from the appellant that he was a social drinker who occasionally used cannabis, ketamine and ecstasy.  The appellant spoke of people who were plotting against him and, out of fear that they might harm him and in order to protect himself, he had harmed his “neighbours”.  Dr Koh observed that the appellant had some insight into his condition in that the appellant had said he was probably suffering from a mental illness.  Dr Koh’s opinion was that the appellant was in a psychotic state and he recommended that there should be an investigation to find out whether or not the reason was related to drug abuse.

14.  Blood and urine samples were taken from the appellant at about 9.15 am on 30 August 2002 which was nearly twenty-four hours after the appellant had launched his knife attack on the four victims.  Both samples gave negative results.  The importance of the negative analysis which resulted from the urine sample was that it could be safely inferred that the appellant had not abused amphetamine, a term which, for present purposes, included both methamphetamine (‘ice’) and MDMA (‘ecstasy’) for at least forty-eight hours preceding the taking of the sample.  For this reason, it was accepted at trial that the appellant had not been acting under the direct influence of dangerous drugs when he killed two of his victims (about twenty-four hours before the samples were taken) and wounded two more.  He was not, in other words, intoxicated by drugs at the material time.  The evidence given at trial indicated that the effects of ‘ice’ and ‘head-swinging’ pills usually subside after a few hours.

15.  The appellant was later transferred to Siu Lam Psychiatric Centre for further observation.

Psychiatric evidence

16.  When this case was first listed before Beeson J in September 2003, she made a ruling, on the basis of the psychiatric evidence then before the court, that it would not be permissible for a defence of diminished responsibility to be raised.  At that time Dr S H Lui provided psychiatric evidence for the prosecution and Dr Chung See-yuen did so for the defence.  As the judge noted:

“5. The psychiatric reports did not differ in any marked respect.  The Defendant was said to be suffering from a drug-induced psychosis during which he had committed the killings.”

17.  Later, the judge said:

“7. The Defendant is not mentally retarded, or mentally disabled.  No evidence of organic brain disease had been put before the court.  He has no previous psychiatric history, nor is there any family psychiatric history.

8. The Defendant is not a drug addict, although he claims to have been a user of various drugs over the last five years including methamphetamine [ice], cannabis, ketamine, ‘head-swinging pills’ and ‘white melon seed’.”

18.  Beeson J also took into account a number of leading authorities where consideration had been given to the effect of alcohol (which would have been equally applicable to dangerous drugs) on defendants who were also suffering from abnormalities of mind at the time when they killed their victims.  These included R v Fenton (below), R v Gittens [1984] 79 Cr App R 272 and R v Deitschmann (below).  In conclusion, the judge said:

“18. Although Dr Chung concludes his report by saying the defendant is suffering from drug-induced psychosis and says: ‘The drug-induced psychosis is a disease of the mind arising from a condition of inherent cause or induced by disease’ – that conclusion is not accurate as it does not conform to the legal basis for diminished responsibility.

19. What is clear is that the defendant was suffering from a voluntary, self-induced, drug psychosis at the time of the killings.  Dr Lui confirmed in his report of 15 September 2003:

‘If the defendant had never taken the drugs, which he claims he has used for several years, of course he would not have killed.’

20. There was no inherent cause, in the legal sense, for his condition.  The defendant was suffering a voluntary, self-induced, transient, psychotic episode.  That it was transient is confirmed by both Dr Chung and Dr Lui.”

19.  Finally, the judge stated:

“24. The psychosis, which results from the use or abuse of drugs, does not amount to an abnormality of mind as it is meant by section 3(1) of the Homicide Ordinance.  Although the psychiatric evidence is extensive in this case, it does not support the defendant’s claim to diminished responsibility.”

20.  By the time the case was listed for trial before Lunn J on 19 April 2005, Dr Chung See-yuen had been replaced by Dr Chan Sai-yin as the defence psychiatrist.  The prosecution’s psychiatrist, Dr Lui, remained the same.  At this stage, however, there was a difference of opinion between the experts, with Dr Chan and Dr Lui being able to agree only that the appellant was suffering from paranoid psychosis which substantially impaired his mental responsibility for his acts.  Dr Lui, who was called to rebut the evidence given by Dr Chan, repeated the view he had always expressed, saying that the appellant’s psychotic condition was brought on by long and heavy abuse of dangerous drugs and in particular ‘ice’ which the appellant admitted he had frequently taken.  Dr Chan’s opinion, on the other hand, was that the psychosis was the probable result of other factors.  This opinion, the opposite of Dr Chung’s in the earlier proceedings, ensured that on this limited basis diminished responsibility became an issue at trial.

21.  The foundation for the difference of opinion between the two psychiatrists as to the cause of the appellant’s psychosis arose because Dr Chan, for the defence, said that the appellant’s psychotic state, which he considered was still present at the time of his only interview with the appellant on 14 February 2005, was unlikely to have been caused by the abuse of dangerous drugs in view of its duration long after the appellant had been denied access to dangerous drugs.  In addition, the defence placed reliance on Professor Thomas Chan, a pharmacologist, whose opinion, as expressed in his report and confirmed in evidence, was that “clinical experience suggests that psychosis may last up to three to six months in extreme cases of high dosage use, even after the drug is withdrawn”.  In Professor Chan’s opinion, if Dr Chan was correct in saying that the appellant’s psychotic condition was still present about thirty months after the fatal stabbings, then the paranoid psychosis was not drug-induced.

22.  Dr Lui, on the other hand, who saw the appellant on a regular basis following the appellant’s admission to Siu Lam, described a psychosis which had built up gradually from about a year after 1997 when the appellant first began to abuse dangerous drugs.  The prolonged abuse had a cumulative effect on the brain.  Dr Lui expressed no doubt in his mind over his diagnosis and this, he stated, was consistent with his finding that the appellant had recovered from his paranoid psychosis by the end of February 2003.  The prosecution also called Associate Professor Koo who described, as an expert in pharmacology, how the symptoms from ‘ice’-induced psychosis can sometimes persist for months or even years.

Summing up

23.  The judge, when summing up to the jury, defined the issue which lay at the heart of the trial in the following way:

“Evidence has been laid before you in the defence case and in rebuttal by the prosecution of the opinions of two psychiatrists.  Each testified that at the time of the stabbing, the defendant was suffering from a paranoid psychosis.  Dr Lui Sing-heung, a consultant psychiatrist and a visiting psychiatrist at the Siu Lam Psychiatric Centre where the defendant has been and is detained, expressed the opinion that the defendant’s paranoid psychosis was an abnormality of the mind which substantially impaired his mental responsibility for his crime or his act.  Dr Chan Sai-yin, a consultant psychiatrist called in the defence case, expressed the same opinion.

The evidence is relevant to the two counts of murder on the indictment.  The law provides that where a person kills another, he shall not be convicted of murder if he was suffering from such an abnormality of mind, whether arising from a condition of arrested or retarded development of mind or any inherent causes, or induced by disease or injury as substantially impaired his mental responsibility for his acts in doing the killing.  I will be giving you a typed sheet with this direction in law, so there is no need to be too worried about notes.

At issue between Dr Lui and Dr Chan is the cause of the abnormality of mind.  Dr Lui expresses the opinion that the paranoid psychosis in the defendant at the time of the killings was drug-induced, that is, induced by his long and heavy use of psychotropic drugs, in particular, methamphetamine, that is ‘ice’, and MDMA, that is, ‘ecstasy’.  Dr Chan, on the other hand, expresses the opinion that the paranoid psychosis in the defendant at the time of the killings, was unlikely to be induced by his abuse of dangerous drugs.  In his opinion, it was probably induced by other factors.

This is the real issue in respect of Counts 1 and 2 on the indictment.  If the prosecution satisfy you so that you are sure of the ingredients of murder about which I will direct you and in writing in due course, it is for the defence to satisfy you on the balance of probabilities, that is, that it is more likely than not of the three elements of the defence of diminished responsibility, in particular, in the circumstances of this case, the defence must satisfy you to that standard that the abnormality of the mind of the defendant at the time of the killing arose from arrested or retarded development of mind or any inherent cause or was induced by disease or injury.

If Dr Lui is probably right that the paranoid psychosis in the defendant was induced from abusing illicit drugs, that is, ‘ice’ and ‘ecstasy’, and not from any inherent cause or disease or injury, then the defence fails.  The element of arrested or retarded development of mind does not arise on the evidence that we have received.

If Dr Chan is probably right, that it is unlikely that the paranoid psychosis in the defendant was induced from abusing illicit drugs and that it is more probable that it arose from another factor, then the defence succeed and the offence of murder is thereby reduced to the offence of manslaughter.” (Appeal bundle pp. 12-13) [Emphasis added]

24.  A little later, the judge added:

“Both doctors – Dr Chan and Dr Lui – are of the opinion that at the time of the events that led to the death of the two victims in Counts 1 and 2, the defendant was suffering from an abnormality of mind that substantially impaired his mental responsibility for his act in doing the respective killing.  The vital issue for you to determine is whether or not the abnormality of mind arose from the matters set out at 2 in the written direction.  That is, arrested or retarded development of mind or any inherent cause or was induced by disease or injury. 

Paranoid psychosis induced by abuse of dangerous drugs including ‘ice’ and ‘ecstasy’ does not come within those terms.  Accordingly, unless the defence satisfy you on all the evidence that it is more likely than not that the paranoid psychosis in the defendant was caused by another factor, then the defence will have failed to establish the second element of the three ingredients it is necessary for them to establish to make out the defence of diminished responsibility.” (Appeal bundle p. 21) [Emphasis added]

25.  In the light of these directions, it is plain that the jury, by their verdicts, rejected the evidence given by Dr Chan to the effect that the appellant’s paranoid psychosis at the time the killings took place had been caused by some factor other than drugs.  This, Dr Lui (appeal bundle page 300) had described as a “remote possibility”.

The application

26.  Mr Loughran submitted that an abnormality of mind amounting to “disease or injury” was sufficient to give rise to the partial defence of manslaughter by reason of diminished responsibility regardless of its cause.  In this sense, therefore, he contended that the main thrust of the passages we have cited from the summing up erroneously focused on the cause of the disease or injury.  This, he argued, would only have been material to the jury’s consideration in the present circumstances if the appellant had been drug-intoxicated at the time he carried out the killings.  We should add for the sake of completion, that there was no suggestion that the appellant was unable to form the specific intent required for murder.  The evidence clearly established that the appellant knew what he was doing when he attacked the victims with a knife.

27.  Although the trial judge had provided a comprehensive direction to the jury on the defence of diminished responsibility in the passage we have already cited from the summing up, we shall, for ease of reference, set out in full the terms of section 3(1) of the Homicide Ordinance, Cap. 339.  This provides that:

“(1) Where a person kills or is a party to the killing of another, he shall not be convicted of murder if he was suffering from such abnormality of mind (whether arising from a condition of arrested or retarded development of mind or any inherent causes or induced by disease or injury) as substantially impaired his mental responsibility for his acts and omissions in doing or being a party to the killing.” [Emphasis added]

The burden (on a balance of probabilities) of establishing diminished responsibility as a partial defence to murder is, by virtue of section 3(2), upon the defence.  It is helpful to add that section 3(1) is couched in identical terms to section 2(1) of the Homicide Act 1957.  This statutory provision introduced ‘diminished responsibility’ in England as a new defence to murder and its interpretation was considered in some of the cases to which we shall in due course turn. 

28.  As we have already said, no issue arose as to whether the appellant was suffering from an “abnormality of mind” at the time of the offences.  It was common ground that he was.  In R v Byrne [1960] 2 QB 396 at 403, where the appellant, a sexual psychopath, strangled a woman before mutilating her body, an ‘abnormality of mind’ was stated by Lord Parker CJ to mean:

“… a state of mind so different from that of ordinary human beings that the reasonable man would term it abnormal.  It appears to us to be wide enough to cover the mind’s activities in all its aspects, not only the perception of physical acts and matters, and the ability to form a rational judgment as to whether an act is right or wrong, but also the ability to exercise will-power to control physical acts in accordance with that rational judgment.”

29.  The judgment went on to deal with the expression ‘responsibility for his acts’, saying that this:

“… points to a consideration of the extent to which the accused’s mind is answerable for his physical acts which must include a consideration of the extent of his ability to exercise will-power to control his physical acts.”

30.  In these proceedings, Mr Loughran has rightly conceded that the appellant’s abnormality of mind did not arise from “arrested or retarded development of mind or any inherent causes”.  The issue, therefore, has centred upon whether, at the time the appellant killed two of the victims at the flat, his abnormality of mind was “induced by disease or injury”.

31.  Dr Lui’s description in his report about the appellant’s abnormality of mind, which he confirmed in evidence, was in these terms:

“… Liu [the appellant] gives a history of abuse of substance, especially ‘Ice’ – methamphetamine – for some five years.  He also took other drugs such as ketamine, cannabis and sedatives.  The after-effect was often irritability and suspiciousness which he says could be ‘slept off’.  According to Liu, he had been using those substances more frequently from early 2002.  He then began to hear imaginary voices, and suspiciousness [which] sometimes turned into periods of paranoia – for example, against the doctors who had treated his nose and knee ailments respectively at around the time – lasting many days. He did not seek psychiatric treatment.  It would appear that Liu had experienced increasing hallucination and delusional ideas of persecution in the week leading up to the index offences.  The last time he took ‘Ice’ is said to be two or three days prior to the violence, the mental symptoms apparently made worse by his failure to sleep properly.  At the material time, Liu recounts he heard voices telling of a ‘massacre’, believed he was in danger, was confused, frightened and impelled to act. Mental examination on admission here found Liu oriented and coherent but in a state of shock at what had happened.  He [spoke] of the deceased as entirely victims.  At the same time he was fearful of reprisal from their family. He reported still hearing voices.  Medication was later prescribed and he is now fully recovered and symptoms free.  Opinion: Liu was suffering from a drug-induced psychosis at the time of the said crime.  This would be an ‘abnormality of mind’ in legal terms which in my opinion substantially impaired his [mental] responsibility for his crime …

……

… The abnormality of mind was the psychosis.  Psychosis is a disease of the mind characterised by abnormal perceptions, hallucinations that is, delusional beliefs and impaired contact with reality.  Drug-induced psychosis, once induced, runs its own course, which may be days, even weeks.  The abnormality did, I believe, substantially impair the defendant’s mental responsibility for his fatal acts, despite the drugs.  If the defendant had never taken the drugs, which he claims he had used for several years, of course he would not have killed.” (Appeal bundle pp. 296-297) [Emphasis added]

32.  Later in his evidence, when Dr Lui was explaining how the onset of the psychosis was a process which occurred over a considerable period of time, he said:

“… my diagnosis on this defendant was based on a large part on the history.  He gave a long history of regular abuse of several drugs, and the psychosis at the time of the [offences] had not emerged suddenly, but, as I have told the court, that, according to the defendant, about a year after he started taking those drugs he already had experienced episodes of brief paranoia, and then by the year 2000 he had experienced episodes of frank paranoid psychosis.  So the psychosis was actually an evolving process looking back at the history, with ideas as he used drugs, the effects appear to have accumulated.  Now, this is compatible with the actions of these drugs because these drugs disturb the dopamine and serotonin neuro-transmitters, those neurons, and there is good evidence that prolonged use of these drugs could cause damage to these neurons.  So the effects, the damaging effects do accumulate … So the long history, the evolving process, I think is the strongest support for the diagnosis of drug-induced psychosis.” (Appeal bundle p.364) [Emphasis added]

33.  Dr Lui had described the abnormality of mind, in the passages we have cited from his evidence, as being the “psychosis” and had described this as a “disease of the mind”.  What is meant by this expression was considered in R v Quick [1973] 1 QB 910 where the appellant was charged with assault occasioning actual bodily harm.  He suffered from diabetes.  Reading from the headnote, evidence was called on his behalf “to show that at the material time he had an abnormally low amount of sugar in his blood and was suffering from hypoglycaemia and submitted that that evidence established that he had acted unconsciously as an automaton.  In the absence of the jury, the judge ruled that the evidence could support only a defence of insanity (rather than automatism) and the appellant then pleaded guilty to the assault”.

34.  Importantly, in the present context, the English Court of Appeal in Quick’s case said (at page 922):

“… Our task has been to decide what the law means now by the words ‘disease of the mind’.  In our judgment the fundamental concept is of a malfunctioning of the mind caused by disease.  A malfunctioning of the mind of transitory effect caused by the application to the body of some external factor such as violence, drugs, including anaesthetics, alcohol and hypnotic influences cannot fairly be said to be due to disease.  Such malfunctioning, unlike that caused by a defect of reason from disease of the mind, will not always relieve an accused from criminal responsibility.  A self-induced incapacity will not excuse (see Reg. v. Lipman [1970] 1 Q.B. 152), nor will one which could have been reasonably foreseen as a result of either doing, or omitting to do something, as, for example, taking alcohol against medical advice after using certain prescribed drugs, or failing to have regular meals while taking insulin.  From time to time difficult border line cases are likely to arise.  When they do, the test suggested by the New Zealand Court of Appeal in Reg. v. Cottle [1958] N.Z.L.R. 999, 1011 is likely to give the correct result, viz., can this mental condition be fairly regarded as amounting to or producing a defect of reason from disease of the mind?”

The judgment in that case continued by stating that if the appellant’s condition existed, his mental condition was not caused by his diabetes but by his use of insulin prescribed by his doctor.  “Such malfunctioning of his mind as there was, was caused by an external factor and not by a bodily disorder in the nature of a disease which disturbed the working of his mind”.  The court, allowing the appeal, decided that the defence of automatism ought to have been left for the jury’s consideration.

35.  It seems, in the present case, that the respondent has seized upon the wording used by the court in Quick’s case to assert, as the trial judge also appears to have done, that as the malfunctioning of the appellant’s mind was not a permanent condition and had “transitory effect” brought on by the voluntary application of dangerous drugs, the psychosis from which the appellant was suffering could not properly be called a “disease” of the mind.  In this regard, Dr Lui, under whose care the appellant has been at all times since these tragic events, suggested in one of his reports which he adopted in evidence (appeal bundle page 354) that the appellant might not have linked his psychotic state, which was itself “very similar to … schizophrenia”, directly to the drugs he was taking.  Dr Chan had earlier dealt with this topic by explaining (appeal bundle pages 124-125) that the appellant’s delusions of being persecuted were not something the appellant would have had any reason to doubt any more, to use the example he gave, than there was any reason to doubt that the pen he was holding (at the time he was giving this testimony) was a blue one.  Even if such a patient tried to doubt the delusion he was having he would, according to Dr Chan, only do so in a “very brief way and then accept it as true … it is so true to him that he did not have to doubt it”.  He went on to say that the appellant would not be aware that his unusual mental experience was anything unusual and would think of himself as totally normal.  Dr Chan, when explaining why the appellant would not connect his psychotic condition to his abuse of drugs, said (with added reference to his written report):

“Furthermore, connecting his unusual mental experiences to his abuse of drugs requires some academic knowledge of drugs, or personal weakness [or] madness in his fellow abusers.  Neither seems to be present.  What I want to say here is that, well just suppose he knew he had some unusual experience, just suppose he did.  He felt himself abnormal, then why should he doubt the cause due to the drugs rather than the pork that he ate this morning?  Just to quote a bizarre association?  Why should he doubt the drug causing his – this abnormal experience?  That would require some academic knowledge of drugs.  That is, he should read somewhere that amphetamine would cause psychosis, but this does not seem to be the case that he had access to the teaching of the side-effects of drugs.  Or he may have another hint.  He abuse amphetamine and many of his friends also abuse amphetamine and he can see that for friends abusing amphetamine they go mad, but for other friends not abusing amphetamine they are normal.  This is a chance that he should also think about his abnormality [related] to abuse of drugs.  But then this is not the case here.  I have already take[n] care of this point in my previous report that he is – among his 20-odd drug-abuse friends, only one, one of his friends has such an experience of being abnormal.  And then this abnormality can be explained even by the defendant.  If you wanted you can see paragraph 3.2 of my first report.  So there even if he had noticed, which is very unlikely, even if he had noticed that he had some unusual mental experience, he could not have connected it to the cause of the abuse of drugs.” (Appeal bundle pp. 125-126)

36.  Bearing all of this evidence in mind, there was nothing in the material before the jury to suggest that the appellant was aware in any shape or form that he was suffering in the way described by the medical experts.  Most importantly, as we have indicated, he was not intoxicated by the effects of dangerous drugs when he killed.  Thus, the circumstances are to be distinguished from the facts which arose in R v Fenton [1975] 61 Cr App R 261 where the appellant, who suffered from an abnormality of mind, had been drinking alcohol to excess before he killed four people.  The English Court of Appeal, when upholding the trial judge’s directions to the jury, stated (at page 263):

“There is no doubt that alcohol was regarded as an important ingredient because the jury later disclosed in reply to an observation of the learned judge that they were unanimously of the view that the killings would not have occurred if the appellant had not had so much to drink. The judge, however, ruled that the effect of the alcohol consumed by the appellant was to be ignored since the effect of the alcohol did not amount to an abnormality of mind due to inherent causes. Accordingly the judge directed the jury that they must convict of murder if satisfied that the combined effect of the factors other than alcohol was insufficient to amount to a substantial impairment in the mental responsibility of the appellant.” [Emphasis added]

37.  Plainly, the crucial factor in Fenton’s case was the alcohol taken just prior to the killings but of importance to the present case is whether the undoubted abnormality of mind which substantially impaired the appellant’s mental responsibility for his acts when killing was a factor to be considered by the jury despite the evidence given by Dr Lui that the psychosis, a disease of the mind, was caused by the appellant’s abuse of dangerous drugs over a long period of time.

38.  The judge, as we have indicated, did not leave ‘diminished responsibility’ to the jury because, in his words, “paranoid psychosis induced by abuse of dangerous drugs … does not come within those terms”.  Mr Loughran argued that this was a wholly different situation to the examples provided by a long line of cases (including Fenton’s case) where the defendants with an abnormality of mind had killed while intoxicated, the evidence of which is to be ignored for the purposes of deciding whether the defence of diminished responsibility has been established.  Here, he submitted, the appellant, unaffected by the direct influence of dangerous drugs, was suffering from a disease of the mind, albeit self-inflicted and caused by his continued abuse of dangerous drugs.

39.  The judge, who had plainly given close consideration to the effect of the authorities and recognised the distinction, nevertheless decided that the effect of what had been said in those cases where defendants had killed while intoxicated by alcohol applied also to the situation which had arisen in this case where the appellant had brought upon himself an abnormality of mind through the prolonged abuse of dangerous drugs.  We have some sympathy for this view as the appellant’s conduct would never have occurred had it not been for his abuse of drugs.  Furthermore, an informed person, knowing of the appellant’s abuse of drugs over many years, might well regard these dreadful acts as no different in moral terms to those of a man who was ‘high’ on drugs or dangerously intoxicated at the time he killed.  Either way, the illicit use of drugs had caused innocent lives to be lost.

40.  Whilst we can well understand the stance taken by the judge, with respect, we feel unable to approach this matter in the same way.  The terms of section 3(1) of the Homicide Ordinance are, we consider, for present purposes clear enough.  The abnormality of mind was an accepted fact at trial and there was no evidence for the jury to have drawn a contrary inference.  It was undisputed that paranoid psychosis was a disease of the mind and so also was the fact that, arising from the abnormality of his mind, the appellant’s mental responsibility for his acts was substantially impaired.  On the face of it, all three criteria necessary to establish this defence to murder were present.  There is no further criterion requiring that the cause of the disease should have been other than one which has been self-inflicted.

41.  It is well-established that a purely transient state, brought on by the recent consumption of dangerous drugs or alcohol, is to be disregarded for the purposes of this defence.  The abnormality of mind in such a case is to be regarded as neither induced by disease (or injury) nor, it is obvious, to have arisen from inherent causes.  The fact that the undoubted abnormality of mind in the present case was caused by a disease which may have been cured, to the extent that the appellant was found by Dr Lui to be “symptoms free” on account of his enforced abstinence from dangerous drugs over the long time he had spent in custody, is not in our opinion something which can properly be said to affect the situation.  Some ‘diseases’ recover in the course of time and section 3(1) makes no mention of a requirement that the disease should be permanent in nature.  Indeed, Mr Loughran drew on other examples where diseases of a non-permanent nature are to be regarded as forming the basis of a defence of diminished responsibility.

42.  In R v Hobson [1998] 1 Cr App R 31, the English Court of Appeal, having heard fresh evidence, allowed an appeal against conviction for murder and ordered a retrial in circumstances where the appellant, who had endured violence at the hands of the deceased on numerous occasions, was said to have been suffering from “battered women’s syndrome”.  This had been newly classified (between the trial and the appeal) as a mental disease and was said to be a variant of post-traumatic stress disorder.

43.  In a further example, Mr Loughran referred us to R v Reynolds [1988] Crim LR 679-680 where the appellant’s murder conviction was substituted by a verdict of manslaughter in circumstances where the appellant was described as “suffering from premenstrual syndrome and postnatal depression of sufficient severity to lead to temporary loss of control and this abnormality of mind was such that substantially impaired her mental responsibility for the killing”.

44.  The focus should, in our view, have been on the existence of the disease rather than the cause of it.  Perhaps the nearest this court has come to deal with the issue presently before us is to be found in HKSAR v Tang Kwok-wai [2000] 2 HKLRD 744 at 749 where it was said that:

“The applicant’s defect of reason was the result of his ‘ice’-induced psychosis and on the expert’s evidence, would subside spontaneously on withdrawal of the drug.  It was transient in nature and caused by an external factor.  There was nothing internal in the applicant’s body that is a disease.  In our opinion a mere temporary disposition or phenomenon displayed by the applicant as a result of taking drugs without more, cannot be regarded as a ‘disease of the mind’ within the Rules.  It is different from that which had been developed into a mental condition similar to schizophrenia and continued despite stopping taking drugs.  The condition of the applicant does not qualify within the definition of ‘disease of the mind’.” [Emphasis added]

45.  In the course of argument, Mr Zervos SC, for the respondent, relying on R v Sanderson [1994] 98 Cr App R 325, argued that the term “disease or injury” in section 3(1) of the Homicide Ordinance referred to organic or physical injury or disease of the body including the brain but that this did not cover a disease or injury to the mind.  If so, he argued, there was no positive evidence to show that the appellant had suffered from organic or physical injury or from a disease of the body.  The court in Sanderson declined to answer what was meant by the phrase “disease or injury” although a view, consistent with Mr Zervos’ submission, was expressed as to what this might mean.  This was more recently taken up in R v McQuade [2005] NICA 331 where the Northern Ireland Court of Appeal, commented (at pages 342-343) on the view expressed by the English Court of Appeal in R v Sanderson when providing its reasons for allowing the appeal.

46.  In McQuade, the applicant had killed his uncle who had allegedly sexually abused him when he was young.  There was agreement by the experts that the applicant suffered from a severe personality disorder which amounted to a disorder of the mind.  Kerr LCJ said:

“[39]  In R v Ireland and R v Burstow ([1998] AC 147, [1997] 3 WLR 534) and, indeed, in R v Chan-Fook ([1994] 1 WLR 689) current scientific thinking was that the body included the mind and that injury to the mind was therefore included in the expression ‘bodily injury’.  In the present case the question that arises is whether s 1 of the 1966 (Criminal Justice) Act (Northern Ireland) includes injury caused to the psyche by abuse in the form of neglect of sexual maltreatment.  If the injury is to the body (including the mind) it appears to us not to matter what the particular mechanism of injury may be.  The important question is whether the mind was injured; not how it was injured.

[40]   The case referred to by counsel for the prosecution, R v Sanderson, did not purport to provide a definitive view on this question.  It was principally concerned with the issue of what constituted disease of the mind.  However, the following obiter passage appears ((1993) 98 Cr App R 325 at 326):

‘Mr Jones submitted that “disease” in the phrase “disease or injury” in section 2(1) meant “disease of the mind” and was apt to cover mental illnesses which were functional as well as those which were organic.  This interesting and difficult question does not, in our view, require an answer in this case … We incline to the view that that phrase “induced by disease or injury” must refer to organic or physical injury or disease of the body including the brain, and that that is more probable because Parliament deliberately refrained from referring to the disease of, or injury to, the mind, but included as permissible causes of an abnormality of mind “any inherent cause” which would cover functional mental illness.’

[40]   In considering this passage we have taken ‘functional’ to mean a disorder without structural change and ‘organic’ to mean constitutional in the structure of the brain.  In as much as this section of the judgment suggests that there must be some physical or structural changes to the brain in order that the effect on the mind can qualify as an injury capable of amounting to an abnormality for the purposes of the relevant sections, we cannot agree with it.  It appears to us that the emphasis must lie on the degree of abnormality and the effect that this has on the mental capacity of the individual affected, rather than the species of injury or the cause of it.” [Emphasis added]

47.  The view expressed by the court in McQuade is one with which we are in agreement.  Everything in the present case points to the appellant having done damage, though not necessarily irreparable or permanent damage, to the brain leading to paranoid psychosis which substantially impaired his mental responsibility for his acts which led to these killings.  This view is arrived at from the evidence given at trial that the psychotic condition suffered by the appellant was one which arose from the appellant’s heavy and prolonged abuse of dangerous drugs.  It hardly needs to be emphasised that the position would have been quite different if the evidence had shown merely that the appellant was intoxicated by the voluntary consumption of dangerous drugs at the time of the killings.  In such a case, without evidence of disease of (or injury to) the mind, the foundation for a defence of diminished responsibility could not have been laid.

48.  The position is more complex where an abnormality of mind is established but the defendant is also shown to have been intoxicated by alcohol or dangerous drugs.  This, as we have said, was the position in R v Fenton (above).  This was further considered in R v Deitschmann [2003] 2 Cr App R 54 where, in a passage taken from the opinion of Lord Hutton (at page 60), unanimously adopted by their Lordships in that appeal, it was stated that:

“In a case where the defendant suffered from an abnormality of mind of the nature described in s. 2(1) and had also taken alcohol before the killing and where (as the Court of Appeal held in this case) there was no evidence capable of establishing alcohol dependence syndrome as being an abnormality of mind within the subsection, the meaning to be given to the subsection would appear on first consideration to be reasonably clear.  I would read the subsection to mean that if the defendant satisfies the jury that, notwithstanding the alcohol he had consumed and its effect on him, his abnormality of mind substantially impaired his mental responsibility for his acts in doing the killing, the jury should find him not guilty of murder but (under subsection 3) guilty of manslaughter.  I take this view because I think that in referring to substantial impairment of mental responsibility the subsection does not require the abnormality of mind to be the sole cause of the defendant’s acts in doing the killing.  In my opinion, even if the defendant would not have killed if he had not taken drink, the causative effect of the drink does not necessarily prevent an abnormality of mind suffered by the defendant from substantially impairing his mental responsibility for his fatal acts.” [Emphasis added]

49.  In the light of the decision in Deitschmann, we should perhaps, in order to lend emphasis to the fact that the most recent drugs taken by the appellant before the killings in the instant appeal, the effect of which would have worn off after a few hours, had no bearing on the psychotic state suffered by the appellant at the material time, refer once more to the expert evidence given at trial which touched upon this aspect.

50.  When Dr Chan was asked (appeal bundle page 226) whether the most recent drugs which the appellant admitted taking about thirty hours prior to the killings (that is, fifty-four hours before the blood and urine specimens were taken) may have caused the drug-induced psychosis, he said that the psychosis was “a prolonged effect” on the chronic and heavy user and that this did not depend on what drugs had been taken recently.  Dr Koo, the prosecution’s expert in pharmacology, said (appeal bundle page 372) that the type of drugs used by the appellant could produce “this persistent type of psychosis for months and sometimes even years after taking the drugs”.

51.  Dr Lui had referred, in the passage to which we referred (at paragraph 32 above), to the damage which could be caused by the regular abuse of dangerous drugs to the neurons in the brain providing, in turn, the “strongest support” for a diagnosis of drug-induced psychosis having regard to the appellant’s history of drug abuse.  Furthermore, when Dr Chan was describing the three ways in which the appellant might have been affected by drugs, namely (1) acute intoxication, (2) drug-induced psychosis and (3) withdrawal syndrome, he ruled out (1) and (3) and said that the second of these factors would be “due to a prolonged, damaging effect” of drugs upon the brain.  However, his opinion (for the reason given at paragraph 21 above) was that there was “less than a fifty per cent chance” that the appellant’s psychosis came about as the result of prolonged abuse of dangerous drugs.

52.  Mr Zervos pointed out that evidence had been given that the appellant was not classified by the experts as a “drug addict”.  Amongst other things, evidence was given that the appellant took psychotropic (or “mind-altering”) drugs in a social context to make him feel “energetic and elated”.  In this regard, he relied upon what was said in R v Tandy [1998] 87 Cr App R 45 where the appellant, who was an alcoholic, consumed nine-tenths of a bottle of vodka before strangling her daughter.  Dismissing the appeal against conviction for murder, Watkins LJ (at page 51) said:

“So in this case it was for the appellant to show: (1) that she was suffering from an abnormality of mind at the time of the act of strangulation; (2) that that abnormality of mind was induced by disease, namely the disease of alcoholism; and (3) that the abnormality of mind induced by the disease of alcoholism was such as substantially impaired her mental responsibility for her act of strangling her daughter.

The principles involved in seeking answers to these questions are, in our view, as follows.

The appellant would not establish the second element of the defence unless the evidence showed that the abnormality of mind at the time of the killing was due to the fact that she was a chronic alcoholic.  If the alcoholism had reached the level at which her brain had been injured by the repeated insult from intoxicants so that there was gross impairment of her judgment and emotional responses, then the defence of diminished responsibility was available to her, provided that she satisfied the jury that the third element of the defence existed.  Further, if the appellant were able to establish that the alcoholism had reached the level where although the brain had not been damaged to the extent just stated, the appellant’s drinking had become involuntary, that is to say she was no longer able to resist the impulse to drink, then the defence of diminished responsibility would be available to her, subject to her establishing the first and third elements, because if her drinking was involuntary, then her abnormality of mind at the time of the act of strangulation was induced by her condition of alcoholism.

On the other hand, if the appellant had simply not resisted an impulse to drink and it was the drink taken on the Wednesday which brought about the impairment of judgment and emotional response, then the defence of diminished responsibility was not available to the defendant.” [Emphasis added]

The court in Tandy determined, amongst other things, that “for a craving for drinks or drugs in itself to produce an abnormality of mind … the craving must be such as to render the accused’s use of drink or drugs involuntary”.  It followed, Mr Zervos submitted, that a defence of diminished responsibility could not be based on a state of mind arising from disease (or injury) if it had been brought about by the voluntary consumption of drink or dangerous drugs.  He contended that, as evidence had been called in the present trial to the effect that the appellant was not a drug addict, it followed that the drugs consumed by the appellant must have been taken voluntarily.

53.  However, what was decided in Tandy was that the voluntary consumption of alcohol by that appellant, rendering her intoxicated at the time she strangled her daughter, meant that the defence of diminished responsibility was not available to her.  What it did not decide was that if the voluntary consumption of alcohol, (and the same in our view would apply had that case been concerned with dangerous drugs), had caused a disease of (or injury to) the mind, and the other criteria necessary to establish diminished responsibility were present, the defence would not arise.  In the present case, we have gone to some lengths to emphasise that the appellant’s most recent (and voluntary) consumption of dangerous drugs some considerable time beforehand had no bearing upon the appellant’s abnormality of mind at the time when the killings took place.

54.  Before leaving Tandy’s case, we observe also that the English Court of Appeal did not cast any doubt on the proposition that a self-inflicted disease of, or injury to, the mind (or brain) such as alcoholism could qualify as a disease or injury for the purposes of raising a defence of diminished responsibility.  Accepting that it did so qualify, the court in that case was saying that this defence was available to the appellant if her alcoholism had reached a level at which her brain had been “injured by the repeated insult from intoxicants so that there was gross impairment of her judgment and emotional responses” or, at a rather lower level of injury, where the damage to the brain was such that the appellant’s consumption of alcohol had become involuntary in the sense that she was “no longer able to resist the impulse to drink”.  Again, reverting to the present case, the position was rather less complicated than in Tandy as the jury was only concerned with the psychiatric evidence.  As we have indicated, not only were all the criteria for a defence of diminished responsibility established, there was nothing to contradict that evidence emanating from any other source.

Conclusion

55.  For the reasons we have given, in our opinion the defence of diminished responsibility should not have been confined to the narrow basis on which it was left.  The alternative basis, which effectively hinged upon the defence establishing that the appellant’s abnormality of mind was induced by disease should also have been left to be determined by the jury, the cause of the disease (long-term drug abuse) being, for present purposes, irrelevant to the establishment of the defence.  We have concluded, therefore, that the judge’s direction to the jury that the defence of diminished responsibility must fail if the paranoid psychosis was induced by the abuse of illicit drugs amounted to a material misdirection.

56.  Accordingly, the appeal is allowed.  The convictions on counts 1 and 2 of murder together with the sentences of life imprisonment will be quashed and we shall substitute manslaughter verdicts on each of the counts.  This decision does not affect the propriety of the convictions for wounding with intent on counts 3 and 4 and the ground of appeal does not suggest otherwise.  There is no basis on which to interfere with these convictions and these, therefore, will stand.

57.  We indicated to counsel that in the event that the murder convictions were quashed we would require, for the purposes of sentence, an updated report from Dr Lui.  From a practical point of view, this may not present much of a difficulty as we understand that the appellant has remained at the Siu Lam Psychiatric Centre until the present time.  We would like Dr Lui to have in mind also the indication we have given to Mr Loughran that it may well be, despite the quashing of the murder convictions, that we would be considering ‘life’ terms for each count of manslaughter.  The respondent’s counsel will no doubt ensure that Dr Lui is so informed so that he can comment, if he feels able to do so, upon the long-term danger represented by the appellant to the community at large. 

58.  Meanwhile, bearing in mind that the appellant has been in custody since 29 August 2002, we shall order that the appellant should remain in custody pending sentence albeit we appreciate that such an order may be unnecessary as the appellant received concurrent 7-year sentences on counts 3 and 4.