After reading this chapter you should be able to:

Understand the law of murder

Understand the law of diminished responsibility

Understand the law of loss of self-control

Understand the law of involuntary manslaughter (constructive, gross negligence and reckless manslaughter)

Understand the law on other homicide offences

Analyse critically the law on homicide, including reform proposals

Apply the law to factual situations to determine whether there is liability for murder or manslaughter

10.1 Actus Reus of homicide

The actus reus elements of murder are as follows:

causing death of a human being

under the King or Queen’s Peace

within any county of the realm

The actus reus is fundamentally the same for manslaughter. Causation was dealt with in Chapter 2.

10.1.1 Human being: birth

A foetus that is killed in the womb cannot be a victim of homicide, although there are other (statutory) offences (see below). When does a foetus become a person in being? It appears that the child must be wholly expelled from the mother (Poulton (1832) 5 C & P 329) and have a separate existence from her (Enoch (1833) 5 C & P 539). That requirement creates its own problems: for example, it is now accepted that a foetus in the womb has an independent circulation within two months of conception. Where a foetus has been born alive but dies afterwards from injuries inflicted whilst in the womb, this may be manslaughter but not murder (Attorney-General’s Reference (No 3 of 1994) (1997) 3 WLR 421, considered in Chapter 3).

10.1.2 Human being: death

A person who is already dead cannot be the victim of homicide. But the legal definition of death has proved elusive. There is conventional death, when the heartbeat and breathing stop. But there is also brain death, when through artificial means the heart continues to beat and air circulates in the lungs. Brain death is recognised by the British Medical Association and is the point when life-support machinery will be switched off. In Malcharek, Steel (1981) 2 All ER 422 (the facts of which were discussed in Chapter 2), the Court of Appeal adverted to this test, although they did not have to decide the point. It is likely that if the question arose squarely, then the courts would adopt the brain death test (or strictly tests, as there are six of them). Thus, if D stabs V who has been certified brain dead but whose functions are being maintained on a ventilating machine, it is unlikely that the Court of Appeal would uphold a murder conviction.

In Inglis (2010) EWCA Crim 2637; (2011) 1 WLR 1110, which is discussed in detail in section 10.2.4 (below), the Court of Appeal rejected an argument that the law of murder did not apply to the ‘mercy’ killing of a severely disabled man. Lord Judge CJ stated:


‘The law does not recognise the concept implicit in the defence statement that [V] was “already dead in all but a small physical degree”. The fact is that he was alive, a person in being. However brief the time left for him, that life could not lawfully be extinguished. Similarly, however disabled [V] might have been, a disabled life, even a life lived at the extremes of disability, is not one jot less precious than the life of an able-bodied person.’

10.1.3 Under the King or Queen’s Peace

This serves to exclude from the scope of homicide enemy soldiers killed in the course of war.

10.1.4 Within any county of the realm

The limitations in this phrase have now all but disappeared. Murder (and manslaughter) committed by a British citizen outside of the UK may be tried in England (ss 9 and 10, Offences Against the Person Act (OAPA) 1861; s 3, British Nationality Act 1948). Murder committed on a British aircraft may be tried in the UK (s 92, Civil Aviation Act 1982). Murder committed on a foreign aircraft coming to the UK may also be tried in England (Civil Aviation (Amendment) Act 1996). The War Crimes Act 1991 confers jurisdiction on English courts over offences of murder (and manslaughter) committed as war crimes in Germany or German-occupied territory during the Second World War.

10.1.5 The year and a day rule

Until 1996 there was a further element: that V had to die within a year and a day. This rule was originally justified because of the difficulty in establishing causation where there was a long interval between the original wound, injury etc and V’s death. The net result was that if D stabbed, shot, strangled or otherwise fatally injured V, but V was kept alive for at least 367 days on a life-support machine before death, D could not be guilty of homicide (see Dyson (1908) 2 KB 454). However, over time, medical science developed to such an extent that the original justification was no longer valid and it was abolished by Parliament in 1996. The main impetus for change was public perception of ‘murderers’ escaping conviction for murder because the victim had been kept alive for more than 366 days. In the case of gross negligence manslaughter, there was not even an alternative offence for which D might be held liable if V survived the 367 days.


‘Law Reform (Year and a Day Rule) Act 1996

1 The rule known as the “year and a day rule” (that is, the rule that, for the purposes of offences involving death and of suicide, an act or omission is conclusively presumed not to have caused a person’s death if more than a year and a day have elapsed before he died) is abolished for all purposes.

2(1) Proceedings to which this section applies may only be instituted by or with the consent of the Attorney-General.

  (2) This section applies to proceedings against a person for a fatal offence if (a) the injury alleged to cause death was sustained more than three years before the death occurred, or (b) the person has previously been convicted of an offence committed in circumstances alleged to be connected with the death.

  (3) subsection (2) “fatal offence” means (a) murder, manslaughter, infanticide or any other offence of which one of the elements is causing a person’s death, or (b) the offence of aiding, abetting, counselling or procuring a person’s death.’

The consent of the Attorney-General is required in two circumstances. First, where several years had passed since the original incident, it was thought to be undesirable to have the history of the case trawled over again in a homicide trial. It would mean some defendants having to live for years with the threat of a murder change hanging over them. Second, where D has already been convicted of a non-fatal offence, or attempt, on the same set of facts. This encourages the prosecution to bring assault or wounding charges earlier, while V is still alive, rather than wait for years to see whether V dies or not.

10.2 Murder

The actus reus elements of murder have been dealt with above. The only remaining element is that of mens rea, ‘with malice aforethought’. This is a legal term — potentially very misleading — which requires neither ill will nor premeditation. A person who kills out of compassion to alleviate suffering (a so-called ‘mercy killing’) acts with malice aforethought — see Inglis (2010), discussed in detail below. Proof of malice aforethought means that a jury is satisfied that, at the time of killing V, D either (Moloney (1985) AC 905)

intended to kill (express malice); or

intended to cause grievous bodily harm (implied malice).

Thus, it is possible for D to be convicted of murder when he intends some serious injury but does not contemplate that V’s life be endangered. This has generated some controversy and calls for reform (see below).

10.2.1 Intention

All of the leading cases on the meaning and scope of intention have involved murder. You should refer back to the discussion of these cases — especially Woollin (1998) 3 WLR 382 — in Chapter 2, for a reminder of the principles.

10.2.2 Grievous bodily harm

The meaning of the phrase ‘grievous bodily harm’ is the same as when the phrase is used in the context of ss 18 and 20 OAPA 1861 (see Chapter 11). In DPP v Smith (1961) AC 290, a murder case, Viscount Kilmuir, with whom the rest of the Lords agreed, held that there was no reason to give the words any special meaning. Thus, he said, bodily harm ‘needs no explanation’ while ‘grievous’ means no more and no less than ‘really serious’. Subsequently, in the context of s 20 OAPA 1861, the Court of Appeal held that the omission of the word ‘really’ when a judge was directing a jury was not significant (Saunders (1985) Crim LR 230). This was confirmed in the context of murder in Janjua and Choudury (1998) EWCA Crim 1419; (1998) Crim LR 675. The Court of Appeal dismissed the defendants’ argument on appeal that the word ‘really’ had to be used in every single murder case.

10.2.3 Procedure in murder trials

In Coutts (2006) UKHL 39; (2006) 1 WLR 2154, the House of Lords allowed an appeal against a murder conviction on the basis that the jury was not allowed to consider manslaughter as an alternative verdict. D had pleaded not guilty, his defence being that V’s death was a tragic accident, but the jury rejected that version of events and therefore convicted him of murder. Lord Rodger explained as follows:


‘The jury were told that they had to choose between convicting the appellant of murder and acquitting him on the ground that the victim had died as a result of an accident. On that basis they chose to convict of murder. But the jury should also have been told that, depending on their view of the facts, they could convict him of manslaughter … The reality is that, in the course of their deliberations, a jury might well look at the overall picture, even if they eventually had to separate out the issues of murder, manslaughter and accident. So, introducing the possibility of convicting for manslaughter could have changed the way the jury went about considering their verdict.’


The Draft Criminal Code (1989), cl 54(1), defines murder as follows: ‘A person is guilty of murder if he causes the death of another (a) intending to cause death; or (b) intending to cause serious personal harm and being aware that he may cause death.’ This would narrow the mens rea of murder from its present common law definition. See also the discussion in section 10.9 below.


Self-test questions

1. Should the definition of murder be amended so as to impose a requirement that, if D did not intend to cause death but did intend to cause serious injury, he also had an awareness that death may be caused?

2. Consider the following scenario. D is a ‘loan shark’. One of his clients, V, is in considerable debt to D but cannot afford to repay it. D decides to physically punish V in such a way that D’s other clients will be left in no doubt as to the consequences if they fail to repay their debts. D specifically wants V to survive the punishment, to provide a long-term reminder of the implications of failing to repay D’s loans. One night D ambushes V and shoots him in the leg with a handgun. The idea is to leave V with a permanent limp. However, the bullet hits an artery and, within minutes, V bleeds to death. Is D guilty of murder:

  a. Under the present common law definition?

  b. Under the Draft Criminal Code?

10.2.4 Mercy killings and euthanasia

The courts have recently been confronted with difficult questions regarding the scope of murder, specifically whether ‘mercy killing’ and/or euthanasia should be treated differently from other deliberate killings. Mercy killing can be defined as the situation where D kills V in order to alleviate V’s suffering. Euthanasia is the situation where V consents to his or her own death, typically because V is suffering from an incurable condition.

The law of ‘mercy killing’ was examined in Inglis (2010) EWCA Crim 2637; (2011) 1 WLR 1110. The Court of Appeal ruled that, as far as the criminal law was concerned, there was no special defence available for those who kill out of compassion: ‘mercy killing’ is murder.


Inglis (2010) EWCA Crim 2637; (2011) 1 WLR 1110

D was charged with the murder of her own son, V, 22, by injecting him with a fatal overdose of heroin. At the time, V was in a ‘desperate state of disability’. Some 18 months‘ earlier, V had suffered serious head injuries after falling from an ambulance and had been in a deep coma on a life-support machine ever since. Two operations had been carried out after the accident, which involved removing part of the front of his skull to relieve pressure on the brain, which left V with a ‘severe disfigurement’. D found all of this extremely depressing and distressing. She regarded the operations as ‘evil’ and wished that V had been allowed to die a natural death; she was convinced that he was in pain and that it was her duty as his mother to release him from his suffering. She became further obsessed with the notion that she had to kill V, quickly and peacefully, to prevent what she regarded as a ‘prolonged and lingering’ death. At D’s murder trial, she relied on provocation but was convicted after the trial judge ruled that there was no evidence of a loss of self-control to support that defence. She appealed, arguing that her case was not murder but a ‘mercy killing’; alternatively, V was so severely disabled as to no longer be a ‘human being’. The Court of Appeal rejected those arguments and upheld her murder conviction, holding that mercy killing was murder, and that V was still a ‘human being’.

Lord Judge CJ stated (emphasis added):


‘The law of murder does not distinguish between murder committed for malevolent reasons and murder motivated by familial love. Subject to well established partial defences, mercy killing is murder. Whether or not he might have died within a few months anyway, [V’s] life was protected by the law, and no one, not even his mother, could lawfully step in and bring it to a premature conclusion.’

The Court of Appeal added that, if ‘mercy killings’ were to be treated differently to other deliberate killings, then that was a matter for Parliament to decide, not the courts. Subsequently, in Nicklinson v Ministry of Justice (2012) EWHC 2381 (Admin) (discussed in Chapter 8), the High Court reached a very similar decision with respect to euthanasia. In reaching that decision, the High Court followed both Inglis and Bland (1993) AC 789 (discussed in Chapter 2) . In Bland, the House of Lords had accepted that, whilst the withdrawal of feeding from a patient in a ‘persistent vegetative state’ was lawful, the deliberate ‘ending of life by active means’ was murder. This was because ‘the interest of the state in preserving life overrides the otherwise all-powerful interests of patient autonomy’ (per Lord Mustill). In Nicklinson, Toulson LJ stated that (emphasis added):


‘The reasons given in Bland and in Inglis for saying that it is for Parliament to decide whether to change the law on euthanasia are compelling and should be followed by this court … It would be wrong for the court to depart from the long established position that voluntary euthanasia is murder however understandable the motives may be.’


Self-test questions

Should ‘mercy killing’ and/or euthanasia be treated differently to other killings, perhaps as an alternative offence or as a defence to murder?

If a defence, should it be a full defence (leading to an acquittal) or a partial defence (leading to a conviction of manslaughter)?

10.3 Voluntary manslaughter

If D is charged with murder there are three ‘special’ and ‘partial’ defences which may be pleaded. They are called ‘special’ as they are only available to those charged with murder, and ‘partial’ because, if successful, D must be convicted of voluntary manslaughter instead. This allows the trial judge more discretion when it comes to sentencing; it also means that D avoids the label of ‘murderer’. With these defences, D is not denying killing V, nor denying malice aforethought, but is asking to be excused from full liability. There are three such defences:

diminished responsibility

loss of control

suicide pact

10.3.1 Diminished responsibility

The defence of diminished responsibility (DR) evolved at common law in the courts of Scotland and was introduced into English law by s 2 of the Homicide Act 1957. That section was amended by s 52 of the Coroners and Justice Act 2009, and it now provides that:


‘2(1)A person (“D”) who kills or is a party to the killing of another is not to be convicted of murder if D was suffering from an abnormality of mental functioning which—

  (a) arose from a recognised medical condition,

  (b) substantially impaired D’s ability to do one or more of the things mentioned in jsubsection (1A), and

  (c) provides an explanation for D’s acts and omissions in doing or being a party to the killing.

(1A) Those things are—

  (a) to understand the nature of D’s conduct;

  (b) to form a rational judgment;

  (c) to exercise self-control.

(1B) For the purposes of subsection (1)(c), an abnormality of mental functioning provides an explanation for D’s conduct if it causes, or is a significant contributory factor in causing, D to carry out that conduct.’

student mentor tip

“Understand the Homicide Act of 1957.”

Anthony, London South Bank University

The background to the reform of DR lies with the Law Commission (LC), who had been advocating modernisation of the definition for several years. For example, in their Report, Murder, Manslaughter and Infanticide, published in November 2006, the LC observed that the ‘definition of diminished responsibility is now badly out of date’. Key amendments made by the 2009 Act are as follows:

‘Abnormality of mental functioning’ replaces the original phrase ‘abnormality of mind’.

‘Recognised medical condition’ replaces the original list of causes: ‘condition of arrested or retarded development of mind’, ‘any inherent cause’ or ‘induced by disease or injury’.

‘Substantially impaired’ ability to ‘understand the nature of D’s conduct’, ‘form a rational judgment’ or ‘exercise self-control’ replaces the original phrase ‘substantially impaired mental responsibility’.

The requirement that D’s abnormality of mental functioning ‘provides an explanation’ for D’s involvement in killing V is a new element of the offence.

Notwithstanding these amendments, much of the case law that built up around the original s 2 will continue to be relevant.

DR is a ‘special’ defence in that it is purely a defence to murder. This allows the trial judge more discretion in terms of sentencing than he would have were D to be convicted of murder, because of the mandatory life sentence. In Campbell (1997) Crim LR 495, the Court of Appeal rejected the argument that DR should be allowed as a defence to attempted murder. This decision must be correct, because the trial judge already has discretion when it comes to sentencing those convicted of attempted murder, and so the defence is simply unnecessary in attempted murder trials. Had it been accepted (and successfully pleaded), moreover, then it would have introduced a new crime into English law: attempted manslaughter.

In Antoine (2000) UKHL 20; (2001) 1 AC 340, the House of Lords held that evidence of DR is not relevant when a jury is deciding whether or not D is fit to stand trial on a charge of murder.


Antoine (2000) UKHL 20; (2001) 1 AC 340

D had been charged with the ‘brutal’ murder of a 15-year-old boy, apparently as a human sacrifice to the devil. He was found unfit to plead under the Criminal Procedure (Insanity) Act 1964, on the basis of paranoid schizophrenia, and another jury was brought in to determine whether he had done ‘the act … charged against him’. He sought to rely upon DR but the judge ruled that it was unavailable. The jury duly found that he had done the act charged, and the judge ordered indefinite hospitalisation. The Court of Appeal and House of Lords dismissed D’s appeals.


D bears the burden of proving DR (Homicide Act 1957, s 2(2)) on the balance of probabilities (Dunbar (1958) 1 QB 1). A successful defence results in a verdict of not guilty to murder but guilty of manslaughter (Homicide Act 1957, s 2(3)). This allows the judge full discretion on sentencing. Some defendants may receive an absolute discharge, others probationary or suspended sentences, while in appropriate circumstances some will receive hospital or guardianship orders under s 37(1) of the Mental Health Act 1983. Others may still face imprisonment, with some receiving life sentences for manslaughter (about 15 per cent of cases). If D raises the defence, and the prosecution has evidence that he is insane then, under s 6 Criminal Procedure (Insanity) Act 1964, evidence may be adduced to prove this. Here, the burden remains on the prosecution to prove insanity. The converse situation is also allowed by s 6, that is, if D raises insanity, then the prosecution may argue it is really a case of DR. Where this happens, the burden is on the prosecution to prove DR beyond reasonable doubt (Grant (1960) Crim LR 424).

Pleading guilty to manslaughter on grounds of DR

Originally, the courts took the view that DR had to be proved to the jury in every case and could not be accepted by a trial judge. However, it is now accepted that D may plead guilty to a charge of manslaughter on the ground of DR. Such a plea would be proper ‘where the medical evidence available, in the possession of the prosecution as well as the defence, showed perfectly plainly that the plea’ was one that could properly be accepted (Cox (1968) 1 WLR 308). In Vinagre (1979) 69 Cr App R 104 the Court of Appeal said that pleas of guilty to manslaughter on the ground of DR should only be accepted where there was ‘clear evidence’ of mental imbalance. The plea was refused in the following cases.

Din (1962) 1 WLR 680. D attacked and killed a man whom he believed was having an affair with his wife, stabbing him several times and almost severing V’s head. After death, D cut off V’s penis. D pleaded DR, based on paranoia induced by an unreasonable belief in his wife’s infidelity. Two medical experts supported the plea; the prosecution was prepared to accept it. However, the judge insisted on leaving the defence to the jury, which returned a verdict of guilty of murder. D’s appeal was dismissed. Lord Parker CJ said that the case was ‘a very good illustration of what for long has been apparent’, namely, that the prosecution were ‘only too ready to fall in with and to support’ a defence of DR.

Walton (1978) 66 Cr App R 25. D shot and killed a random stranger, a 16-year-old girl. Charged with murder, he pleaded DR. Two defence medical experts described D as ‘retarded in certain respects’, suffering from ‘an extremely immature personality’ and ‘having an inadequate personality enhanced by emotional immaturity and low tolerance level’. The jury, however, rejected the defence. The Privy Council rejected D’s appeal. Lord Keith said that the jury was entitled to regard the medical evidence as ‘not entirely convincing’.

Where D pleads DR but it is rejected by the jury, the Court of Appeal may, if it believes the murder conviction to be unsupported by the evidence, quash it and substitute one of manslaughter. This happened in the following cases.

Matheson (1958) 2 All ER 87. D killed a 15-year-old boy. The medical experts agreed that D was suffering a mental abnormality but the jury rejected the defence. D’s murder conviction was quashed on appeal. Lord Goddard CJ said that where there was ‘unchallenged’ evidence of medical abnormality and ‘no facts or circumstances appear that can displace or throw doubt on that evidence’ then the Court was ‘bound’ to say that the conviction was unsafe.

Bailey (1961) Crim LR 828. D battered V, a 16-year-old girl, to death with an iron bar. Three medical experts agreed that D suffered from epilepsy, that he had suffered a fit at the time of the killing, and that it had substantially impaired his mental responsibility at that time. The jury rejected the defence. D appealed and his murder conviction was quashed.

According to research (S Dell, ‘Diminished Responsibility Reconsidered’ (1982) Crim LR 809) in practice 80 per cent of pleas of guilty to manslaughter on grounds of DR are accepted. Where the case does go to trial (usually because the prosecution disputes the defence), there is about a 60 per cent chance of conviction for murder. Thus the overall failure rate of the defence is quite small, around 10 per cent.

Importance of medical evidence

Medical evidence is crucial to the success of the defence. In Byrne (1960) 2 QB 396 it was said that, while there is no statutory requirement that a plea be supported by medical evidence, the ‘aetiology of the abnormality … does, however, seem to be a matter to be determined on expert evidence’. Thus, where D was suffering a condition that was not, at the time of the trial, regarded by psychiatrists as a mental condition the defence will be unavailable but, if the condition subsequently becomes so regarded, a conviction may be quashed. This was the outcome in Hobson (1998) 1 Cr App R 31.

The Court of Appeal in Dix (1982) 74 Crim LR 302 declared that medical evidence was a ‘practical necessity if the defence is to begin to run at all’. The jury were not, however, bound to accept that evidence if there was other material, which, in their opinion, conflicted with and outweighed the medical evidence. Occasionally, the jury may be faced with conflicting medical evidence. They are then required to weigh up and choose between the different opinions.

Operation of the defence

Section 2(1) breaks down into four components:

There must be an ‘abnormality of mental functioning’.

It must arise from a ‘recognised medical condition’.

D must have a ‘substantially impaired’ ability to understand the nature of their conduct, or form a rational judgement, or exercise self-control.

The abnormality must provide an ‘explanation’ for D’s acts and omissions in doing or being a party to the killing.

There are no further requirements nor exceptions. In Matheson (1958) it was accepted that the fact that a killing was premeditated did not destroy a plea of DR and this remains the position today.

‘Abnormality of mental functioning’

This is a new phrase, introduced by the 2009 amendment, to replace ‘abnormality of mind’. The reason for the change was explained by the Law Commission (LC) in their Report, Murder, Manslaughter and Infanticide (November 2006), at para 5.111. The LC stated that the original definition in s 2(1) had not been ‘drafted with the needs and practices of medical experts in mind, even though their evidence is crucial to the legal viability’ of any DR defence. The phrase ‘abnormality of mind’ was ‘not a psychiatric term’, and it received no further definition in the statute. As the LC pointed out, ‘its meaning has had to be developed by the courts from case to case’. As it happens, the courts had interpreted the phrase very widely, most famously in Byrne (1960) 2 QB 396, where Lord Parker CJ described it as ‘a state of mind so different from that of ordinary human beings that the reasonable man would term it abnormal’. It will be interesting to see if the courts in the future interpret the new phrase as widely. Note that there is nothing in the legislation to indicate that the ’abnormality of mental functioning‘ has to have any degree of permanence. Nor is there any requirement that the mental abnormality should have existed since birth (Gomez (1964) 48 Cr. App. R. 310). It should suffice that it existed at the time of the killing.

A ‘recognised medical condition’

This is another of the 2009 amendments. The original s 2(1) required the ‘abnormality of mind’ to arise from a ‘condition of arrested or retarded development of mind’ or ‘any inherent cause’ or be ‘induced by disease or injury’. That list has now been consolidated into the single, simpler, but potentially wider, requirement of a ‘recognised medical condition’. The Law Commission explained the thinking behind the redefinition in their 2006 Report by pointing out that ‘diagnostic practice’ in DR cases ‘has long since developed beyond identification of the narrow range of permissible causes’ stipulated in s 2(1). Moreover, the LC observed that ‘the stipulated permissible causes never had an agreed psychiatric meaning’. A further improvement is the long-overdue removal of the obsolete — and insulting — reference to retardation as a means of supporting a plea of DR.

The government agreed, claiming that the redefinition will bring ‘the existing terminology up-to-date’ whilst allowing for ‘future developments in diagnostic practice’ and encouraging defences to ‘be grounded in a valid medical diagnosis linked to the accepted classificatory systems which together encompass the recognised physical, psychiatric and psychological conditions’ (Ministry of Justice Consultation Paper, Murder, Manslaughter and Infanticide ( July 2008), para 49).

No further definition of ‘recognised medical condition’ is provided in the Act so it will be interesting to see how the courts apply this new criterion. However, it is not unreasonable to expect that the courts will, in the future, be prepared to accept the following conditions, all of which fell within the scope of the original s 2(1):

Adjustment Disorder (Dietschmann (2003) UKHL 10; (2003) 1 AC 1209; Brown (2011) EWCA Crim 2796; (2012) Crim LR 223)

Alcohol Dependence Syndrome (discussed below)

Asperger’s Syndrome (Jama (2004) EWCA Crim 960)

Battered Woman Syndrome (Hobson (1998))

Depression (Gittens (1984) 3 All ER 252; Seers (1984) 79 Cr App R 261; Ahluwalia (1992) 4 All ER 869;Swan (2006) EWCA Crim 3378)

Epilepsy (Bailey (1961); Campbell (1997) 1 Cr. App. R. 199)

Othello Syndrome, a form of extreme jealousy (Vinagre (1979) 69 Cr App R 104)

Paranoia (Simcox (1964) Crim LR 402)

Premenstrual Tension and Postnatal Depression (Reynolds (1988) Crim LR 679)

Psychopathy (Byrne (1960); Hendy (2006) EWCA Crim 819)

Schizophrenia (Moyle (2008) EWCA Crim 3059; Erskine (2009) EWCA Crim 1425, (2009) 2 Cr. App. R. 29;Khan (2009) EWCA Crim 1569)

It is possible that there will be more than one cause of D’s ‘abnormality of mental functioning’. If both causes are medical conditions (as in Reynolds (1988)), then if anything D’s defence is strengthened. However, if one of the causes is a medical condition but the other is not, the latter must be discounted. This situation has been raised before the courts a number of times where D pleaded DR and was also intoxicated. These cases will be examined below.

The Law Commission had suggested that ‘developmental immaturity in a defendant under the age of 18’ should be able to support a plea of DR, separately from a ‘recognised medical condition’. However, the government rejected this. In its Consultation Paper, Murder, Manslaughter and Infanticide (July 2008), the Ministry of Justice asserted that the term ‘recognised medical condition’ would cover conditions ‘such as learning disabilities and autistic spectrum disorders which can be particularly relevant in the context of juveniles’. There was therefore no need to have a separate category alongside ‘recognised medical condition’.

‘Substantially impaired ability to understand the nature of conduct, or form a rational judgment, or exercise self-control’

This is another amendment, replacing the original expression used in s 2(1), ‘substantially impaired mental responsibility’. The amendment was brought about after the government accepted the Law Commission’s criticism in its 2006 Report that the phrase ‘mental responsibility’ was too vague. The LC had argued (at para 5.110) that the ‘implication’ was that D’s mental abnormality ‘must significantly reduce the offender’s culpability’ but without saying, precisely, how or in what way it did so. The redefinition makes explicit what was, at best, implicit in the original version of the Act. Now D must prove that his abnormality of mental functioning impaired his ‘ability to understand the nature of [his or her] conduct’ and/or ‘form a rational judgment’ and/or ‘exercise self-control’.

In Byrne (1960), the Court of Criminal Appeal said that the question of whether D’s impairment could be described as ‘substantial’ was a question of degree and, hence, although medical evidence was not irrelevant, one for the jury. This was confirmed in Eifinger (2001) EWCA Crim 1855, the Court of Appeal describing this question as ‘the jury’s function’. More recently, in Khan (2009) EWCA Crim 1569, the Court of Appeal acknowledged that ‘scientific understanding of how the mind works and the extent to which states of mind and physical responses to them have physical or chemical causes have undoubtedly advanced considerably’ since the time when Byrne was decided. However, despite those advances, the Court said that ‘even today, it is impossible to provide any accurate scientific measurement of the extent to which a particular person’ might be able to ‘understand or control his physical impulses on a particular occasion’. In short, there was no ‘scientific test’ for measuring this aspect of the DR defence. It remained a question for the jury. It seems reasonable to assume that this will continue to be the case under the amended statute.

As to what is meant by ‘substantial’, in Lloyd (1967) 1 QB 175, the trial judge, Ashworth J, directed the jury as follows:


‘Substantial does not mean total, that is to say, the mental responsibility need not be totally impaired, so to speak, destroyed altogether. At the other end of the scale substantial does not mean trivial or minimal. It is something in between and Parliament has left it to you and other juries to say on the evidence, was the mental responsibility impaired and if so, was it substantially impaired?’

The direction from Lloyd was confirmed as still representing the law under the reformed defence in Brown (2011). This clearly gives juries a wide discretion. Sympathy/empathy for the defendant is crucial. On the one hand, it is not uncommon for manslaughter verdicts to be returned in cases with little evidence of abnormality but where D has reacted to situations of extreme grief or stress. Thus mercy killers, or killings committed by the severely depressed, may receive convictions for manslaughter instead of murder. Conversely, murder convictions have been returned in cases when the psychiatrists all agreed that D was suffering severe mental abnormality but whose actions evoked little or no jury sympathy. The classic example is the Yorkshire Ripper, Peter Sutcliffe, who in 1981 was charged with murdering 13 women. Despite medical evidence from four psychiatrists that he was suffering from Paranoid Schizophrenia, the case went to trial. The jury rejected his DR plea and he was convicted of murder.

The abnormality must provide ‘an explanation’ for D’s acts and omissions in doing or being a party to the killing

This requirement, in s 2(1)(c), is an entirely new legal principle, introduced by the 2009 amendment. The Law Commission (LC) proposed that this amendment be made and the government agreed. Section 2(1B) further provides that ‘an abnormality of mental functioning provides an explanation for D’s conduct if it causes, or is a significant contributory factor in causing, D to carry out that conduct’. It essentially means that there must now be some causal connection between D’s mental abnormality and the killing.

However, notice the use of the word ‘an’, as opposed to ‘the’, before the word ‘explanation’ in s 2(1)(c). This means that, although the ‘abnormality’ must at least be ‘a significant contributory factor’ for D killing, it need not necessarily be the only reason for doing so. The government agreed with the LC that it would be ‘impractical’ to require mental abnormality to be the ‘sole’ explanation for D’s killing of V, on the basis that ‘it is rare that a person’s actions will be driven solely from within to such an extent that they would not otherwise have committed the offence, regardless of the influence of external circumstances, and a strict causation requirement of this kind would limit the availability of the partial defence too much’ (Ministry of Justice, Murder, Manslaughter and Infanticide Consultation Paper (July 2008), para 49).

Diminished responsibility and intoxication

It is now well established that a state of intoxication (falling short of the level of intoxication at which D fails to form mens rea) on its own cannot be used to support a plea of DR. In Fenton (1975) 61 Cr App R 261, Lord Widgery CJ said that ‘We do not see how self-induced intoxication can of itself produce an abnormality of mind’. This has been confirmed as still representing the law under the reformed defence. In Dowds (2012) EWCA Crim 281; (2012) 3 All ER 154, it was argued that, because ‘Acute Intoxication’ appears in the World Health Organisation’s International Statistical Classification of Diseases & Related Health Problems (ICD), where it is defined as ‘a condition that follows the administration of a psychoactive substance resulting in disturbances in level of consciousness, cognition, perception, affect or behaviour, or other physiological functions or responses’, it was therefore a ‘recognised medical condition’ for the purposes of s 2. The Court of Appeal rejected this argument, stating that, if Parliament had meant to alter the law as decided in Fenton, it would have made its intention explicit. Hughes LJ pointed out that a variety of conditions appeared in the ICD and / or the American Medical Association’s Diagnostic & Statistical Manual that would not support a plea of DR, such as ‘unhappiness’, ‘irri-tability and anger’, ‘suspiciousness and marked evasiveness’, ‘pyromania’, ‘pae-dophilia’, ‘sado-masochism’, ‘kleptomania’, ‘exhibitionism’ and ‘sexual sadism’. Hughes LJ stated:


‘It is quite clear that the re-formulation of the statutory conditions for [DR] was not intended to reverse the well-established rule that voluntary acute intoxication is not capable of being relied upon to found [DR]. That remains the law. The presence of a “recognised medical condition” is a necessary, but not always a sufficient, condition to raise the issue of [DR] … Voluntary acute intoxication, whether from alcohol or other substance, is not capable of founding [DR].’


Dowds (2012) EWCA Crim 281; (2012) 3 All ER 154

D and his girlfriend, V, were both ‘habitual, heavy binge drinkers’. One night, D stabbed V 60 times, mostly in the neck, severing the carotid artery causing her to bleed to death. At the time, both had drunk a lot of vodka. At his murder trial, D did not deny being the killer but pleaded lack of intent due to intoxication and/or loss of control. The jury rejected both of these and he was convicted of murder. D appealed, arguing that DR, based on a state of ‘acute intoxication’, should have been left to the jury. The Court of Appeal disagreed and upheld his murder conviction.

However, what is the situation where D suffers from an underlying abnormality of mental functioning (eg, depression) and kills whilst intoxicated? This issue has arisen on several occasions, and the courts have taken a consistent line: a plea of DR may not be supported with evidence of voluntary intoxication. The trial judge should direct the jury to ignore the effects of the intoxication and consider whether the medical condition on its own would have been enough to amount to an abnormality of mental functioning. This was the decision in Gittens (1984) 3 All ER 252.


Gittens (1984) 3 All ER 252

D was suffering depression and had, on the night in question, consumed a large amount of drink and antidepressant pills. In this state he clubbed his wife to death with a hammer and then raped and strangled his 15-year-old stepdaughter. He was convicted of murder but the Court of Appeal allowed his appeal, on the basis that the underlying depression may on its own have amounted to an ‘abnormality of mind’. The Court did stress, however, that the jury should be directed to disregard the effect (if any) on D of any alcohol or drugs consumption.

This decision was confirmed by the Court of Appeal in Egan (1992) 4 All ER 470, where it was said that ‘the vital question’ for the jury in such cases is to ask, ‘was the appellant’s abnormality of mind such that he would have been under diminished responsibility, drink or no drink?’ In Dietschmann (2003), it was further held that it was wrong to ask a jury whether D would still have killed V, even if he had not been intoxicated. The question was whether or not D would have had an ‘abnormality of mind’, even if he had not been drinking.


Dietschmann (2003) UKHL 10; (2003) 1 AC 1209

D killed V by punching him and kicking him in the head in a savage attack. At the time of the killing, D was heavily intoxicated, in addition to suffering from an ‘adjustment disorder’, a ‘depressed grief reaction’ to the recent death of his girlfriend. At his trial for murder D relied on DR. The expert evidence for D was that, as well as the adjustment disorder, he had suffered a ‘transient psychotic episode’ at the time of the incident so that, even if he had been sober, he would still probably have killed V. The Crown’s case was that the alcohol had been a significant factor as a disinhibitor and that, if D had been sober, he would probably have exercised self-control. The judge directed the jury that the question was whether D would still have killed V had he not been drinking, and the jury convicted. D appealed and although the Court of Appeal dismissed the appeal, he was successful in the House of Lords. The jury had been misdirected.

Lord Hutton suggested the following model direction for future juries:


‘Assuming that the defence have established that [D] was suffering from mental abnormality as described in s 2, the important question is: did that abnormality substantially impair his mental responsibility for his acts in doing the killing? … Drink cannot be taken into account as something which contributed to his mental abnormality and to any impairment of mental responsibility arising from that abnormality. But you may take the view that both [D]’s mental abnormality and drink played a part in impairing his mental responsibility for the killing and that he might not have killed if he had not taken drink. If you take that view, then the question for you to decide is this: has [D] satisfied you that, despite the drink, his mental abnormality substantially impaired his mental responsibility for his fatal acts, or has he failed to satisfy you of that? If he has satisfied you of that, you will find him not guilty of murder but you may find him guilty of manslaughter. If he has not satisfied you of that, the defence of diminished responsibility is not available to him.’

Dietschmann has been followed by the Court of Appeal in a number of DR cases:

Hendy (2006) EWCA Crim 819; (2006) 2 Cr App R 33: D admitted killing V while intoxicated on alcohol, but there was evidence of an underlying brain damage and a psychopathic disorder.

Robson (2006) EWCA Crim 2749: D was heavily intoxicated, but also suffering from an ‘acute stress disorder’, when he killed V.

Swan (2006) EWCA Crim 3378: intoxication on top of underlying depression.

In each case, the jury had been directed that a defence of DR required proof that D would still have killed had they been sober. In each case the Court of Appeal, following Dietschmann, quashed the resulting murder convictions and substituted convictions of manslaughter. However, the rule of law laid down in Dietschmann and applied in Hendy, Robson and Swan now has to be read in the light of the amended s 2(1), specifically the requirement that D’s abnormality of mental functioning provide ‘an explanation’ for the killing. Thus, in future cases involving a combination of underlying abnormality plus intoxication, as in Gittens, Egan, Dietschmann and so on, the jury should be directed to:

(a) ignore the effect of D’s drinking and/or drug-taking

(b) decide whether D’s underlying abnormality arose from a ‘recognised medical condition’

(c) decide whether this underlying abnormality substantially impaired D’s ability to understand their conduct, form a rational judgement and/or exercise self-control

(d) decide whether the underlying abnormality caused, or was a ‘significant contri-butory factor’, in D’s killing of V

In short, whilst the courts had held that it was wrong for the trial judge in such cases to ask juries to decide whether D would have killed had he been sober, Parliament has decided that juries should, in future, be asked to decide whether D might have done so. This is because, if D definitely would not have killed V (or anyone else) had he remained sober, then there cannot be any causal connection between the underlying condition and the killing, as required by s 2(1)(c), and D would be liable for murder.

Diminished responsibility and alcoholism

Different rules apply where it is suggested that D’s ‘abnormality of mental functioning’ was itself caused by long-term alcohol and/or drug abuse, and that D has developed a medical condition, sometimes known as Alcohol Dependence Syndrome (ADS). In Fenton (1975), Lord Widgery CJ in the Court of Appeal envisaged the possibility that a craving for drink or drugs could produce an ‘abnormality of mind’. However, until recently the leading case in this area was Tandy (1989) 1 WLR 350, in which Watkins LJ added a very important caveat, holding that alcoholism on its own would not suffice for a plea of DR. Instead, it would have to be proved (by the defence) that either D’s 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 … judgment and emotional responses’ or, if not, that D’s ‘drinking had become involuntary, that is to say she was no longer able to resist the impulse to drink’.

The decision in Tandy was criticised on the basis that it unduly limited the scope of the defence. One commentator argued that ‘very few, if any, alcoholics will be permanently in a condition where the immediate consumption of alcohol is required to prevent or assuage the symptoms of withdrawal from alcohol’ (G R Sullivan, ‘Intoxicants and Diminished Responsibility’ (1994) Crim LR 156). Another commentator criticised the rule in Tandy that D’s drinking must be ‘involuntary’ before alcoholism can be used to support a DR defence. Goodliffe pointed out that, under Tandy, ‘the symptoms of the disease are seen in isolation from the disease itself, leaving the idea of “disease” devoid of meaning’ (J Goodliffe ‘Tandy and the Concept of Alcoholism as a Disease’ (1990) 53 MLR 809). Despite this criticism, in Inseal (1992) Crim LR 35, the Court of Appeal followed Tandy . In that case D, an alcoholic, had killed his girlfriend whilst in a drunken stupor. He claimed that he was either too drunk to have the intent to kill (the intoxication defence; see Chapter 9) or, if he did have the intent, his alcoholism was an ‘abnormality of mind’. The jury convicted and the Court of Appeal dismissed the appeal. The jury must have been satisfied that D could have resisted the temptation to drink and that ‘accordingly’ any ‘abnormality of mind’ was not induced by ADS.

However, in two recent decisions, the Court of Appeal has shown more sympathy for defendants who kill whilst suffering from ADS. In the first case, Wood (2008) EWCA Crim 1305; (2009) 1 WLR 496, the court held that the ‘rigid’ principles established in Tandy (1989) had to be ‘re-assessed’ in the light of the House of Lords’ decision in Dietschmann (2003). The court laid down the following principles.

Alcohol Dependence Syndrome (ADS) is a condition which may amount to an ‘abnormality of mind’. Whether it does or not is a matter for the jury to decide.

It is not essential that brain damage has occurred — although if it has, that can only help D to prove the defence.

If D’s syndrome does amount to an ‘abnormality of mind’, then the jury must then consider whether D’s mental responsibility was substantially impaired.

In deciding that question the jury should focus ‘exclusively’ on the effect of alcohol consumed by D as a ‘direct result’ of D’s condition but the jury should ‘ignore the effect of any alcohol consumed voluntarily’.


Wood (2008) EWCA Crim 1305

After a day’s heavy drinking, Clive Wood killed V in a frenzied attack with a meat cleaver. At Wood’s murder trial, four psychiatrists agreed that Wood suffered from alcohol dependence syndrome, but the trial judge told the jury that a verdict of manslaughter based on DR was only open to them if D’s consumption of alcohol was truly involuntary, and that simply giving into a craving for alcohol was not involuntary drinking. D was convicted of murder but the Court of Appeal quashed his conviction and substituted a verdict of manslaughter.

Sir Igor Judge stated:


‘The sharp effect of the distinction drawn in Tandy between cases where brain damage has occurred as a result of alcohol dependency syndrome and those where it has not is no longer appropriate.’

Commenting on Wood in the Criminal Law Review, Professor Andrew Ashworth states:


‘If there is no proof of brain damage it is still open to the jury to decide that the alcohol i dependency syndrome amounted to an “abnormality of mind” within s.2. If they do so, I then the next question is whether that abnormality “substantially impaired” D’s responsibility, discounting any effects of alcohol consumed voluntarily. So the jury are left to determine how much of D’s drinking derived from his alcohol dependency and how much was I “voluntary”. This is a fearsomely difficult question to ask.’

Partly as a result of this criticism, Wood was followed — and clarified — in Stewart (2009) EWCA Crim 593. Here, the Court of Appeal quashed D’s murder conviction (but ordered a retrial) because the jury had been directed in accordance with the ‘rigid’ directions laid down in Tandy. At D’s retrial, the jury would be directed in accordance with the new, more flexible, principles laid down in Wood. To provide further clarification, Lord Judge CJ in Stewart established the following three-step test.

1. Was D suffering from an ‘abnormality of mind’? The mere fact that D has ADS will not automatically amount to such an ‘abnormality of mind’, because the jury need to assess ‘the nature and extent of the syndrome’.

2. Was D’s ‘abnormality of mind’ caused by the ADS? If the answer to question (1) was yes, then this is likely to be straightforward.

3. Was D’s ‘mental responsibility’ ‘substantially impaired’? Here, the jury should be directed to consider all the evidence, including any medical evidence. The issues likely to arise would include (a) the extent and seriousness of D’s dependency; (b) the extent to which his ability to control his drinking or to choose whether or not to drink was reduced; (c) whether he was capable of abstinence from alcohol and, if so, (d) for how long; and (e) whether he was choosing for some particular reason, such as a birthday celebration, to get drunk, or to drink more than usual. D’s pattern of drinking in the days leading up to the killing and his ability to make ‘apparently sensible and rational decisions’ about ordinary day-to-day matters at the relevant time might all bear on the jury’s decision.


Key facts on diminished responsibility



Defi nition

abnormality of mental functioning

arising from a recognised medical condition

which substantially impairs D’s ability to understand the nature of D’s conduct, form a rational judgement or exercise self-control

and which provides an explanation for D’s

s 2(1) and (1A) Homicide Act 1957 (as amended by s 52 Coroners and Justice Act 2009)
Abnormality of mental functioning A new expression, introduced by the 2009 Act. None yet
Recognised medical condition

A new expression, introduced by the 2009 Act, to replace the list of causes in the original 1957 Act. However, the pre-reform cases provide examples of likely ‘conditions’:


Battered Woman Syndrome





Wood (2008)
Hobson (1998)
Seers (1984)
Bailey (1961)
Byrne (1960)
Erskine (2009)
Substantially impaired A question for the jury to decide.
‘Substantial’ does not mean total or trivial but something in between.
Byrne (1960); Khan (2009) Lloyd (1967); Brown (2011)
Effect of intoxication Intoxication must be ignored.
Where D has an underlying mental disorder, the question is whether this disorder on its own amounts to an abnormality of mental functioning.
Fenton (1975); Dowds (2012)
Gittens (1984); Dietschmann (2003); Hendy (2006)
Effect of alcoholism Alcohol Dependence Syndrome (ADS) may amount to an abnormality of mental functioning.
It is not necessary to prove either brain damage or that all of D’s drinking was involuntary.
Whether it substantially impairs D??s ability to understand his or her conduct / form a rational judgement / exercise self-control is to be decided by a jury, ignoring the effect of any alcohol consumed voluntarily.
Wood (2008); Stewart (2009)
Burden of proof It is for the defence to prove, on the balance of probabilities. S 2(2) Homicide Act 1957; Dunbar (1958)
Effect of defence The charge of murder is reduced to manslaughter. s 2(3) Homicide Act 1957


10.3.2 Loss of self-control

Loss of self-control is a new special and partial defence to murder, introduced by ss 54 and 55 of the Coroners and Justice Act 2009. It replaces the ancient common law defence of ‘provocation’, which was abolished by s 56(1) of the 2009 Act.

Background to the reform

The Law Commission (LC) had been advocating reform of the provocation defence for several years. In their Report, Murder, Manslaughter and Infanticide (November 2006), they stated that the ‘defence of provocation is a confusing mixture of judgemade law and legislative provision’. The government agreed. The Ministry of Justice Consultation Paper, Murder, Manslaughter and Infanticide: Proposals for Reform of the Law (July 2008), states (para 34):


‘We want to provide a partial defence which has a much more limited application than the current partial defence of provocation. We propose to do this … by abolishing the existing partial defence of provocation and the term “provocation” itself which carries negative connotations.’

The common law provocation defence had already been modified by Parliament, in s 3 of the Homicide Act 1957, which has been repealed by s 56(2) of the 2009 Act. For the purposes of comparison, s 3 is set out here:


‘Where on a charge of murder there is evidence on which the jury can find that the person charged was provoked (whether by things done or by things said or by both together) to lose his self-control, the question whether the provocation was enough to make a reasonable man do as he did shall be left to be determined by the jury; and in determining that question the jury shall take into account everything both done and said according to the effect which, in their opinion, it would have on a reasonable man.’