Essay: The defence of insanity in English law

“The criminal legal system provides a defence for people who, as a result of their mental condition, should not be held responsible for what would otherwise be criminal conduct. This is the defence of “insanity” and the present form of that defence dates from 1843”.
Where the mental illness is of such a severe nature that a person cannot distinguish fantasy from reality, and cannot seem to conduct her/his affairs due to psychosis, or is subject to uncontrollable impulsive behaviour. Insanity is distinguished from low intelligence or mental deficiency due to age or injury.
In order to be convicted of a crime, the prosecution must prove that the accused did what is alleged in the charge and, in most cases, that he or she did so with some particular mental element. The accused might rely on defences including that of “insanity”. The insanity defence is set out in “the M’Naghten Rules” as laid down by the House of Lords in 1843:
The M’Naghten rules states “Every man is to be presumed to be sane, and … that to establish a defence on the ground of insanity, it must be clearly proved that, at the time of the committing of the act, the party accused was labouring under such a defect of reason, from disease of mind, and not to know the nature and quality of the act he was doing; or if he did know it, that he did not know he was doing what was wrong.” It is the Defendant bears the burden of proving on the balance of probabilities that he or she is insane within that test. If the test is met, in the Crown Court the defendant is found “not guilty by reason of insanity” which is known as the “special verdict”.
The test that determines if a defendant can distinguish right from wrong is based on the idea that the defendant must know the difference in order to be convicted of a crime. Determining a defendant’s ability to do so may seem straightforward enough, but dilemmas often arise in cases in which the M’Naghten standard is used. For example, some issues focus on whether a defendant knew that his or her criminal acts were wrong or whether he or she knew that laws exist that prohibit these acts.
A person found not guilty by reason of insanity has not been convicted of any crime and so he or she cannot be sentenced. The term “disposal” is therefore used to describe the main ways in which a court may deal with such a person. Following a special verdict, the Crown Court has the power to make an absolute discharge, a supervision order or to order that the person be detained in hospital, possibly with the restriction that he or she is not to be released until permission is given by the Secretary of State. Permission for release will depend on the person’s mental health and the risk to the public that he or she poses. This position differs in the magistrates’ courts, and the range of disposal powers is narrower.
1.2 Automatism
Automatism has been clearly defined as “An act which is done by the muscles without any control by the mind, such as a spasm, a reflex action or a convulsion; or an act done by a person who is not conscious of what he is doing, such as an act done whilst suffering from concussion or whilst sleep-walking”
Lord Denning also held that sleepwalking may give rise to the defence of automatism in the case of
Bratty v. Attorney-General for Northern Ireland he stated “It seems to me that any mental disorder which has manifested itself in violence and is prone to recur is a disease of the mind. At any rate it is the sort of disease for which a person should be detained in hospital rather than be given an unqualified acquittal.”
If a person totally lacked control of his or her body at the time of the offence, and that lack of control was not caused by his or her own prior fault, then he or she may plead not guilty and may be acquitted. This is referred to as the defence of automatism. It is a common law defence and it is available for all crimes. Once the accused has called enough evidence to make automatism a live issue in the trial, the prosecution must disprove the defence; if they fail to do so the defendant will be acquitted. There is no special verdict. The defence of automatism is evidently so closely related to that of insanity that reform of one entails reform of the other.
Chapter 2 – Criticisms and problems with the present law surrounding Insanity
The precise wording of the central part of the M’Naghten Rules is as follows, with numbers added to assist in following the subsequent discussion:
Jurors ought to be told in all cases that every man is to be presumed to be sane, and to possess a sufficient degree of reason to be responsible for his crimes until the contrary be proved to their satisfaction and that to establish a defence on the ground of insanity, it must be clearly proved that, (1) at the time of the committing of the act, (2) the party accused was labouring under such a defect of reason, (3) from disease of the mind as (4) not to know the nature and quality of the act he was doing, or (5) if he did know it, that he did not know he was doing what was wrong.10
(1) The requirement to prove D’s “act”
In the Crown Court, for the verdict of not guilty by reason of insanity to be given, the prosecution must prove that the accused “did the act or made the omission”. This means that the prosecution have to prove “the ingredients which constitute the actus reus”, and are not required to prove any mental element (mens rea) . The actus reus can be described as the conduct element of an offence. For example, in the case of criminal damage, the actus reus is causing damage to property belonging to another. It is not always easy to identify precisely what must be proved because in some instances the elements of an offence cannot easily be classified as either actus reus or mens rea. In cases where the actus reus realistically requires some awareness of the action (such as where a person possesses or keeps an item, or permits an activity) it is not so obvious. The case law acknowledges this difficulty but leaves it unresolved.
This problem is not confined to only a few offences. In recent years, large numbers of offences have been created which blend a mental element into the actus reus. Difficulties would arise if a plea of not guilty by reason of insanity was raised by a defendant facing charges for such an offence.
We asked consultees whether this problem had thrown up difficulties in practice. One respondent provided an example of a case of assault where the accused believed he was defending himself. The CPS pointed out a further consequence of this problem:
In cases where a mental element has been blended into the actus reus, the “trial of facts” is indistinguishable from the full trial so where the “actus reus” has not been proved beyond reasonable doubt the defendant is acquitted. The original purpose of the trial of facts was to protect the defendant from being subject to the power of the criminal court to commit him to hospital for an indefinite period, where there was no evidence that he had committed an offence. The purpose of the special verdict is also frustrated as in its absence the court has no power to make a hospital order for the therapeutic benefit of the defendant or a restriction order to protect the public.
(2) The interpretation of “defect of reason”
The term “defect of reason” has been interpreted to mean that for the defence of insanity to operate, the accused’s powers of reasoning have to be impaired at the time of the commission of the offence. A mere failure to use powers of reasoning is not enough. Momentary failure of concentration, even where caused by mental illness, is not insanity within the M’Naghten Rules.
The definition of “defect of reason” also excludes from the scope of the insanity defence abnormalities of mind such as an inability to control one’s emotions or compulsions. These do not reflect impaired powers of reasoning. This narrow construction of the defence has met with telling criticism from leading academics. As Professor Ashworth notes, “some forms of mental disorder impair practical reasoning and the power of control over actions”. He argues that it follows that the power of controlling one’s actions “should clearly be recognized as part of a reformed mental disorder defence”.
(3) Disease of the mind
The M’Naghten test requires the accused to be suffering from a “defect of reason from disease of the mind”. The kind of disorder that is relevant is not necessarily a disease in the ordinary sense of that word, and the word “mind” is not interpreted to mean “brain”.
Significantly, therefore, “disease of the mind” is not limited to mental illness: “it means a disease which affects the proper functioning of the mind”. “Mind” here means, in the words of Lord Diplock, “the mental faculties of reason, memory and understanding”. What matters is the effect of the impairment, as he explained:
“If the effect of a disease is to impair these faculties so severely as to have either of the consequences referred to in the latter part of the rules, it matters not whether the aetiology of the impairment is organic, as in epilepsy, or functional, or whether the impairment itself is permanent or is transient and intermittent, provided that it subsisted at the time of commission of the act”
Judges give the phrase a more modern interpretation in practice: in the guidance given to judges on how to direct the jury “disease of the mind” is described as “an impairment of mental functioning caused by a medical condition”.
Some conditions are clearly going to be regarded as diseases of the mind, for example, schizophrenia. However, one consequence of the courts’ broad interpretation of “disease of the mind” is that people with conditions that would not be described generally as mental disorders have been held to come under the M’Naghten understanding of insanity. These include, for example, sleepwalkers, and people with epilepsy or diabetes
This has come about because the law has not distinguished between mental disorders and physical disorders so that the latter are outside the notion of “disease of the mind” in M’Naghten. Instead, it has adopted a distinction between whether the cause of the accused’s lack of control was due to an “internal factor” (ie some malfunctioning of the person’s body) or an “external factor” (such as a blow to the head or substances taken). Involuntary conduct caused by an “internal factor” is classed as insanity and that leads to the special verdict. Involuntary conduct caused by an “external factor” is classed as (sane) automatism, leading to a simple acquittal. This leads to illogical results. The “line drawn between sane and insane automatism can never make medical sense”. It “makes illogical, hair-splitting distinctions inevitable, allowing some an outright acquittal while condemning others to plead guilty or take the risk of a special verdict”, and, as Lord Justice Hughes has recently said:It is well known that the distinction drawn in Quick between external factors inducing a condition of the mind and internal factors which can properly be described as a disease can give rise to apparently strange results at the margin
The application of the law to diabetics demonstrates this most starkly. Diabetics may suffer excessively high blood sugar (hyperglycaemia) or excessively low blood sugar (hypoglycaemia), and both states may be caused by “external factors” (alcohol or insulin) or “internal factors” (lack of food or insufficient insulin). In Hennessy, the defendant had a hyperglycaemic episode caused by his failure to take a prescribed dose of insulin. His loss of control was created by a factor internal to him so his reliance on that at trial was classified as a plea of insanity. In contrast, in Quick the loss of control arose when a diabetic suffered a hypoglycaemic attack following his failure to eat after taking insulin. His loss of control was an external cause and was therefore classified as an automatism plea. The Court of Appeal held that there will be no “disease of the mind” under the M’Naghten Rules where a malfunction was “caused by the application to the body of some external factor such as violence, drugs, including anaesthetics, alcohol and hypnotic influences”.
The upshot is that a diabetic who, without fault, fails to take insulin and then commits an allegedly criminal act would be treated as insane. In contrast, a diabetic who took insulin in accordance with a medical prescription would be acquitted if he or she was an automaton at the time of committing an allegedly criminal act, whether that was because he or she had an unexpected reaction to the insulin or because having taken the insulin he or she failed to eat through no fault of their own. As Professor Ashworth has written: There can be no sense in classifying hypoglycaemic states as automatism and hyperglycaemic states as insanity, when both states are so closely associated with such a common condition as diabetes.
Beyond its application to diabetes, another basis for criticism is that with some conditions, both internal and external factors may operate simultaneously, as in sleepwalking or hypnosis: some people are more susceptible to sleep disorders, but then there may be an external trigger (an interruption to sleep) which also plays a part in loss of capacity.
A yet further difficulty with this boundary between internal (insanity) and external (automatism) has arisen in so-called “psychological blow” cases where the accused enters into a dissociative state following a traumatic event. We discuss this in the context of automatism (see paragraph 5.47 and following below).
We noted in the supplementary material to the Scoping Paper that a diabetic who falls into a hyperglycaemic coma and then commits an offence may be surprised and offended to hear a court rule that, following precedent, because his or her loss of voluntary control was internal, namely arising from the condition of diabetes, if he or she wishes to plead not guilty on the basis of the medical condition, it must be a plea of not guilty by reason of insanity. One respondent to the Scoping Paper wrote that it was “unpalatable” that he, as a diabetic, should be labelled “insane” in law, and Lord Justice Davis wrote that the distinction between internal and external conditions is “illogical, little short of a disgrace and should be abolished”. Lord Justice Davis presided over the trial of Brian Thomas, who was charged with murder of his wife. His defence was that he killed her when he was in the throes of “night terror violence” (akin to sleepwalking). The prosecution decided not to proceed with the case. Other than this case, however, only one other instance was provided of a sleepwalking case which ought, in the respondent’s view, to have been dealt with under the M’Naghten Rules.
Despite the breadth of the definition of disease of the mind, the other elements of the M’Naghten Rules are construed so narrowly that the defence will be denied to many with serious mental disorders. We turn now to consider the core elements of the defence.
(4) The “nature and quality of the act”
One way in which a defendant might satisfy the M’Naghten Rules, and thereby be found insane, is by showing that he or she did not know the nature and quality of his or her act. This nature and quality limb of the defence may be thought too narrow in two ways. First, it is based on an unduly narrow concept of what must be known. The courts have held that the insanity defence is unavailable if the defendant has knowledge of the physical aspects of the act alleged even if he or she does not have knowledge of the moral aspects of his or her act . It is clear that in this (physical) sense it will be very rare indeed for a person with a relevant medical or physical condition not to know the nature and quality of his or her actions. Secondly, an exclusive focus on cognitive questions excludes other sorts of problems in the functioning of minds and brains, such as mood disorders or emotional problems.
(5) “He did not know he was doing what was wrong”
The second way in which the defendant might rely on insanity is if he or she can satisfy the “wrongfulness limb” of the M’Naghten Rules by showing that even if he or she was aware of the nature and quality of the act he or she was not aware that it was wrong. The issue of interpretation that has troubled the courts here is whether “wrong” means “contrary to law”, or “morally wrong”.English law has adopted an unusually, and arguably unjustifiably, narrow interpretation of the “wrongfulness” limb. In Windle, Lord Goddard interpreted it as meaning that if the accused knew that what he or she is doing was against the law, then the insanity defence is not available.
The effect has been:
To close off the possibility of expanding the interpretation of the word “wrong” … to include situations where the accused’s mental disorder prevented him from realizing that his actions could not be rationally justified.
Consider, as an example, the US case of Andrea Yates. Yates, a woman with a history of mental illness, drowned all five of her children in a bath. Believing that Satan had been conversing with her, she concluded she needed to kill her children while they were still innocent to save them from an eternity of torment in hell. Yates knew she was killing her children and a sign of her premeditation was her awareness of the special problem her eldest child Noah (aged 7) would pose to her course of action, given his developing physical strength. According to the “nature and quality” limb as interpreted by Codère,. Yates did know the nature and quality of her acts. Someone in her position would not be able to rely on this limb of the insanity defence in English law.
(6) Incoherence
A further theoretical problem, and one with potentially significant practical consequences, is that it is unclear whether the insanity defence is essentially a denial of mens rea or a denial of responsibility for the crime. Our view is that the true rationale of the defence is to deny criminal responsibility, not merely to deny mens rea. This follows from the view that it would be fundamentally unfair and unjust to hold someone criminally responsible for their conduct if, through no fault of their own, they lacked the capacity to obey the law.
If a defence of insanity is merely a denial of mens rea, then the defence is irrelevant if there is no mens rea element to the offence. Conversely, if a defence of insanity is a denial of criminal responsibility, then the availability of the defence should not depend on whether there is a mens rea element to the offence. This is not merely a theoretical concern. Consider the following example. The accused is charged with the offence of causing a water discharge activity, in other words, polluting surface water, which is a strict liability offence, punishable in the magistrates’ courts by up to £50,000 and/or 12 months’ imprisonment, and in the Crown Court by an unlimited fine/up to 5 years’ imprisonment. The accused, who suffers from delusions, including that he has been entrusted by a supernatural power with the task of saving the world, pollutes the water because he believes he has been commanded to do so. If the insanity defence is only relevant to mens rea, then he would be held responsible and convicted (unless dealt with outside the criminal justice process).