Diminished responsibility cases

Swot, a student in a university hall of residence, is subject to attacks of somnambulism when he overworks. One night, just before his final examinations, he walks, fast asleep, into the room of his neighbour, Miles, and stabs him in the chest with a steel ruler, which was lying on Miles' desk. Miles' screams awaken Swot, who then realises what he has done and runs quietly back to his room, leaving Miles to bleed to death. Discuss.

In order to examine the offences that Swot may be charged with, this night should be divided into two distinct episodes; firstly when Swot stabs Miles and then when he leaves Miles injured in his room. Some may argue on the basis of Thabo Meli1 that this should not be broken into two parts, but rather seen as one long continuing act. This would be a but for the purposes of analysis this division is pertinent. 1) Miles is stabbed by Swot Actus reus The prosecution will first accuse Swot of the murder of Miles. The definition of murder is that it is the unlawful killing of another human being, with malice aforethought.

2 Prima facie, the actus reus when Swot stabs Miles, but to be successful the prosecution will have to prove that Swot had the corresponding mens rea for murder at this time. When identifying the actus reus one can look at the defendant's behaviour, the consequences and surrounding circumstances. In this problem, we must begin by deciding whether Swot's acts were factual and legal causes of Miles' death. The 'but for' test can be used to establish factual causation, as in R v White3; i. e. 'but for the defendants acts, would the victim have died?

' This can be answered affirmatively in this case, so we can move on to establishing legal causation. A case establishing a useful test for this is R v Smith4, where the defendant's act was said to have been an 'operating and substantial cause of the death'. This applies here, and it seems that legal causation is also easy to establish in the present case, and there are no identifiable intervening acts. Mens Rea In the case of murder, the prosecution will need to prove Swot's intention to cause death or grievous bodily harm (GBH).

5 Furthermore following Woolin6, it must also be proven that the defendant saw death as a virtually certain result of his conduct. It is here that the prosecution will run into trouble; after all how can they say a man who was asleep at the time of this episode had an intention to do anything, let alone the intention to kill or cause GBH. In Swot's Defence Automatism: Automatism is probably Swot's strongest defence; representing a lack of mens rea, when the performance of actions is without awareness or conscious intent. It is legally defined as acting involuntarily.

There are two types of the condition: insane automatism and non-insane automatism. Insane automatism is caused by a "disease of the mind" within the M'Naghten Rules7, while non-insane automatism is linked to external factors. 8 The importance of the distinction between the two forms rests on the verdict; sane automatism operates as a straightforward denial of voluntariness and leads to an outright acquittal, whereas insane automatism is treated as a type of insanity, for which there is a special verdict9 and a different burden of proof upon the defendant. 10

Until fairly recently it was assumed that sleepwalking was the paradigm case of automatism – "Can anyone doubt that a man, who, though he may be perfectly sane, committed what would otherwise be a crime in state of somnambulism, would be entitled to be acquitted. "11 The recent Canadian case of Parks12 is a classic example of sleepwalking found to be sane automatism, where the defendant was acquitted on the basis of the unanimous expert medical evidence to the effect that the his condition was not the result of mental illness but rather of a simple sleep disorder.

13 However in domestic law the recent case of Burgess14 is the precedent and here, by contrast with Parks, the expert medical opinion, following the line taken in Rabey15 and Hennessy16, was that sleepwalking was a mental abnormality, was transmitted through heredity and hence, though there were external triggers such as drugs and stress, which can precipitate sleepwalking, the episodes were due to an internal factor, namely the inbuilt tendency of the person to sleepwalk.

17 While there have been recent cases involving sleepwalking where the defendant has been acquitted, for example in the cases of Davies18 and Bilton19 these are anomalous with the results in both Burgess and Lowe unless it can be argued that the 'external factor doctrine' has outlived its usefulness,20 as has been found in Canada. 21 Consequently, it is probable that Swot will succeed on a defence of insane automatism, rather than sane, provided he can prove that he was asleep when he stabbed Miles.

A predisposition to sleepwalking can be proven through medical tests. 22 However even if Swot can prove he was asleep, the prosecution has several grounds for recourse. Firstly, Swot knows that when he overworks he is subject to attacks of somnambulism, and although there is no evidence to say that he has been overworking, his finals are imminent.

Therefore one should ask if there was anything he could have done to prevent stress and thus avoid an attack of somnambulism, because 'what is essential to the denial of responsibility for a defendant's involuntary behaviour is that she was unable deliberatively to control that behaviour and to prevent it from occurring. The case of Bailey23 found however that although the episode was self-induced, he could still be acquitted if he was unaware that the consequence would likely lead to violence.

Diminished Responsibility If Swots defence of automatism fails, then he could employ the defence of diminished responsibility. This defence does not guarantee acquittal, however it would reduce the murder charge to manslaughter. If Swot is to succeed under this defence, it needs to be shown that his somnambulism is an abnormality of the mind within the definition of the Homicide Act 1957, and that the abnormality is so great as to substantially impair his responsibility.

24 Furthermore in Byrne25 it was found that to prove diminished responsibility the state of mind must be different from a normal human-being to the extent that a reasonable man would find it abnormal. Swot can use medical evidence to support his claim that somnambulism constitutes diminished responsibility however as was seen in Saunders the jury has the power to dismiss even unanimous medical opinion when considering diminished responsibility cases.