10.1.2 Insanity, Automatism and Intoxication Lecture

1.0 Introduction

Where the defendant is charged with a crime there are several ways he can go about attempting to exonerate himself of legal responsibility, reduce his liability or lessen his sentence. This can be done through arguing the facts of a case, arguing a case on a point of law, arguing mitigating circumstances or establishing a defence in his favour. In law, there exist many different types of defences and one defence may fall under a multitude of the categories. These categories include:

  • Complete defences: These defences exonerate the accused of any criminal liability
  • Partial defences: These defences have the effect of reducing the charge to a lesser charge
  • General defences: These can be pleaded in relation to all crimes
  • Special defences: These can only be pleaded in relation to the specific crimes which. For example, murder carries special defences unique to the offence.
  • Excusatory defences: These defences apply so that the accused could not have committed the crime due to an absence of criminal intent or mens rea.
  • Justificatory defences: These defences apply where the accused admits they committed a criminal act but that their actions can be justified and therefore they should not be criminally culpable.

These notes focus on three different defences: Insane automatism, non-insane automatism and intoxication. These defences are all general, excusatory defences. The requirement of each defence and the effect of a successful plea of each are discussed and set out.

2.0 Automatism

As stated above, automatism is as a general defence that can be pleaded in relation to all crimes. There are two types of automatism: Insane automatism and non-insane automatism. The distinction as to which defence applies comes from whether the cause of the defendant’s behaviour was internal or external. In order to understand this distinction, consider the two similar cases of Hennessey and Quick, both involving defendants suffering from diabetes.

Case in Focus

R v Hennessy [1989] 1 WLR 297

The defendant was an insulin dependent diabetic who did not take any insulin and went without food for a period of days which caused him to suffer from hyperglycaemia. In this case the Court held that the defendant’s behaviour was caused by the internal factor of the non-regulation of the blood sugar and as such the correct defence of his behaviour was insane automatism.

Case in Focus

R v Quick [1973] QB 910

The defendant was charged with assault. He had taken insulin and then consumed some food and drink which caused him to suffer from hyperglycaemia. It was held by the Court that the external factor of the insulin caused the behaviour and thus the correct defence was non-insane automatism.

2.1 Insane Automatism

This defence is often referred to as insanity but the technically correct phrase is insane automatism. The two terms will be used interchangeably throughout. Note that this is a legal defence and is not reflective of any medical condition. The result of a successful plea is a finding of not guilty by reason of insanity.

2.1.1 Criteria

The criteria for the defence was established in the case of M’Naghten (1843) 8 ER 718 and is referred to as the M’Naghten rules. These set out that for a successful plea of insanity the following must be established:

  • The defendant laboured under a defect of reason;
  • Arising from a disease of the mind;
  • So that he did not know the nature and quality of his act, OR;
  • He did know that what he was doing was wrong.

In law, everyone is presumed sane. Once the prosecution have established the actus reus beyond all reasonable doubt, the onus is then on the defendant to establish that he fulfils the criteria of insanity but as there is a reverse burden he must satisfy a lower standard of showing this on the balance of probabilities. Section 1 of the Criminal Procedure (Insanity and Unfitness to Plead) Act 1991 requires the defendant in establishing the defence to adduce evidence from two or more registered medical practitioners.

Case in Focus

R v M’Naghten (1843) 8 ER 718

The defendant, Daniel M'Naghten was obsessed with the Prime Minister at the time, Sir Robert Peel. M’Naghten attempted to kill the Prime Minister by shooting him but instead shot and killed Edward Drummond who was the Prime Minister's Secretary. At trial it became evident that M'Naghten was suffering from insane delusions at the time of the killing and was found not guilty by reason of insanity. This led to public outcry due to the high profile nature of the crime. In upholding the findings, the House of Lords set out what subsequently became known as the M'Naghten rules. Speaking at paragraph 719, Lord Tindal CJ explained that “In all cases of this kind the jurors ought to be told that every man is 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 at the time of committing the act the party accused was labouring under such a defect of reason, from disease of the mind, as not to know the nature and quality of the act he was doing, or as not to know that what he was doing was wrong.".

Examination Point

Learn these criteria and ensure that you can recite them exactly in an exam. You will need to be confident in applying them and the first step towards that is being able to fully set out the requirements of the defence. Make sure you explain that the onus is on the defendant as getting confused and stating that the onus is on the prosecution will lose you marks.

2.1.2 Defect of Reason

This is a high standard to meet as the defendant must prove that he was deprived of his power to reason. A temporary distraction or absentmindedness will not suffice.

Case in Focus

R v Clarke [1972] 1 All ER 219

The defendant having been charged with theft, admitted that she had taken the goods but only because she was absentminded at the time due to depression. The Court held this was not sufficient to constitute a defect of reason and the defence failed.

2.1.3 Disease of the Mind

The definition for what constitutes a disease of the mind is a legal definition confirmed in R v Sullivan [1984] AC 156, and not a medical one. Accordingly, it encompasses a number of things that doctors would be very reluctant to classify as such, for example diabetes. A disease of the mind relates to a disease affecting the mental faculties of reason, memory and understanding, and cannot arise from an external cause. This can be a difficult concept to apply but there is lots of case law to help assist in its understanding.

Case in Focus

R v Kemp (1957) 1 QB 399

A husband violently attacked his wife with a hammer and was charged with causing grievous bodily harm. At the time of the attack he suffered from a medical condition of hardening of the arteries which lead to a congestion of blood in the brain which caused a lack of consciousness so that he was not aware of what he was doing.  The Court held that the hardening of the arteries was a disease of the mind within the M'Naghten Rules despite the fact it was not a degeneration of the brain. Devlin J stated that the important issue is the state of mind of the accused, not how he got there and the mind did not mean the brain instead it referred to the ordinary mental faculties of reason, memory and understanding. 

Case in Focus

R v Sullivan [1984] AC 156

The defendant was prosecuted for kicking a man. At the relevant time he was suffering from epilepsy. The judged ruled that this was rightly classed as an internal factor and thus the disease of the mind and stated that the duration or temporary nature of the suspension of the mental faculties of reason, memory and understanding, particularly where it is a recurrent issue, is not relevant to the application of the M’Naghten Rules.

Case in Focus

R v Burgess [1991] 2 WLR 1206

The defendant had been sleeping over a friend’s flat when he attacked a her whilst he was sleepwalking, hitting her over the head and grabbing her throat. She screamed and he came round showing immediate horror at his actions. The sleepwalking was held be an internal factor and sufficient to constitute a disease of the mind.

Examination Point

Learn this list and the cases as you will need to be able to cite them in the likely instance that you are confronted by one such situation in a problem scenario. Make sure you understand the distinction between a medical disease of the mind and what would constitute such disease in law for the purposes of insane automatism. Avoid seemingly becoming confused between the two by falling into the trap of focussing on psychiatric conditions and use the case law to focus your discussion on whether the issue in question impaired the defendant’s mental faculties of reasoning, memory and understanding.

2.1.4 Effect of Defect

There are two alternative elements that could be shown here for a plea to be successful. These are either or elements, although it may be possible to show both.

2.1.4.1 Nature and Quality

This relates to the defendant’s ability to recognise what he was physically doing and the physical consequences of that. For example, Lord Denning’s example of the defendant throwing a baby on the fire believing it to be a log or the oft cited example of cutting off a sleeping victim’s head as a joke to make him see it when he wakes up.

Case in Focus

R v Codere (1916) 12 Cr App R 21

The defendant cut his wife’s throat thinking it was a loaf of bread. He was charged with murder. In handing down the verdict the Court confirmed that the element of the M'Naghten rules relating to a defendant’s knowledge of the nature and quality of his act was held to refer to the physical nature of the act, not its legal or moral character. A defendant, such as Codere that knows that killing is legally wrong may still be precluded from understanding the physical nature of his actions in killing someone.

2.1.4.2 Wrong

This asks whether the defendant knows what he is doing is legally wrong, as opposed to morally wrong. Consider the case of R v Windle [1952] 2 QB 82 for an illustration of this.

Case in Focus

R v Windle [1952] 2 QB 82

The defendant was a man who suffered from a physiological disability and had very low resolve. He was in an unhappy marriage with a woman who was suffering from severe depression and had asked him to kill her. He abided and gave her an aspirin overdose. The police came to arrest the defendant upon where he declared “I suppose I’ll hang for this”. This indicated that despite his defect of reason arising from the disease of the mind, he did realise what he was doing was legally wrong, even though he could not comprehend why it was morally wrong. Accordingly, the plea of insanity failed.

Case in Focus

R v Johnson [2007] EWCA Crim 1978

This case law confirmed the ruling in Windle. In this instance, the defendant who was suffering from paranoid schizophrenia stabbed his victim. Whilst he was clearly labouring under a defect of reason arising from a disease of the mind, medical evidence drawn from an assessment of the accused stated in his defence that he thought he had a moral right to do this. This was insufficient as the accused at all times knew that his actions were legally wrong. Accordingly, the defence of insanity was not available to him.

Examination Point

The requirement of legal knowledge on the part of the defendant has attracted a lot of criticism. As evidenced from the two cases discussed it operates harshly on defendants that are mentally ill and who really should be afforded the defence. The Butler Committee on Mentally Abnormal Offenders concluded in a 1975 report that knowledge of the law was a very narrow ground of exemption as even people who are severely disturbed generally possess the knowledge that murder is a crime. What do you think? Could you propose a more suitable test in relation to this arm of the M’Naghten guidelines?

2.1.5 Effect of a Successful Plea

The effect of a successful plea is a special verdict of not guilty by reason of insanity. The defendant will then be made the subject of a disposal order under the Mental Health Act 1983.

2.2 Non-Insane Automatism

Somewhat confusingly this defence is also referred to as just automatism. It was defined by Lord Denning in Bratty v Attorney General for Northern Ireland [1963] AC 386 as an act which is done by the muscles without any control by the mind or an act done by a person who is not conscious of what he is doing. In lay terms, the defence applies in situations where by reason of an external cause the defendant’s mind has no control over the actions of his limbs, for example, a spasm, involuntary reflex or convulsion. The oft cited example here is the swarm of bees scenario quoted by Lord Goddard in Hill v Baxter [1958] 1 All ER 193, and proposed in Kay v Butterworth (1945) 61 TLR 452. Consider a driver is going along when a swarm of bees come through the window and start attacking the driver. The driver would have an involuntary instinctive reaction triggered by the attack and could not be legally responsible for this.

The requirement that the defendant have no control over his limbs means that in cases where the defendant retains some, albeit limited control, the defence will fail. This was highlighted in the case of Broome v Perkins (1987) 85 Cr App R 321 where a diabetic suffering from a hyperglycaemic attack was charged with driving without due care and attention. He retained the ability to negotiate junctions and swerve away from vehicles and thus had some control over his body so the defence failed.

2.2.1 Effect of a Successful Plea

The effect of a successful plea of non-insane automatism depends entirely on the charge facing the defendant. If the defendant is charged with a specific intent crime he will be acquitted following a successful plea. If the charge is a basic intent crime then he will likely be acquitted but only where he was not reckless in becoming an automaton.

2.2.1.1 Specific or Basic?

Up to this point in your studies you will probably understand the distinction to be that an offence with a mens rea of intention and nothing less is a specific intent crime, where as any other mens rea, such as recklessness or negligence, or even strict liability crimes are basic intent offences. Unfortunately, the distinction is not that straight forward!

Examination Point

This is an examiner’s favourite for an essay question! There is an abundance of case law existing on the matter and you will need to know the cases and explain the distinction provided between the two classes of offence in each case. It will come up again later on in relation to intoxication so unfortunately there is no short cut or way around it here and you will just have to memorise it.

The starting case point came in R v Morgan [1976] AC 182, where it was held that specific intent meant crimes with an ulterior intent. In R v Majewski [1977] AC 443, this was adapted to mean crimes where there was a purposive element to the mens rea. In R v Caldwell [1982] AC 341, the approach taken was to look at the wording of the charge, if the charge stated intention then the offence would be a specific intent crime, anything less and it would be classed as a basic intent crime. R v Heard [2008] QB 43, confused things further as the Court classed the offence of sexual assault which requires intentional touching by the defendant as a basic offence crime which followed the Morgan decision but conflicted directly with Caldwell.

Examination Point

As can be seen from the above narrative on the development of the definition, the law remains uncertain here. Thankfully for examination purposes some crimes such as murder, theft, robbery and s.18 grievous bodily harm are all non-contentiously classed as specific intent crimes. In other cases if it is not obvious you will usually be told whether the offence is a specific or basic intent crime so don’t panic too much. The marks come from recognising that there is a distinction and explaining the law accordingly as opposed to correctly identifying whether the crime is specific or basic.

2.2.1.2 Reckless Defendant

If the automatism was caused by the defendant’s own doing, for example through drinking too much or consuming illegal drugs, the defence of automatism will not be available. In all other cases, regardless of whether the offence is specific or basic intent, the defendant will almost always be acquitted. The only instance in which the specific/basic distinction matters is where the defendant has been reckless in becoming an automaton. Whether the defendant has been reckless is a subjective question to be determined on a case to case basis with regard to the defendant’s knowledge of the risk.

Case in Focus

R v Bailey [1983] 1 WLR 760

The defendant committed an assault whilst he was suffering from hypoglycaemia. He had injected himself with insulin and then neglected to consume any food. The Court rejected his defence of automatism holding that where a defendant realises there is a risk that his conduct may lead to unpredictable and uncontrollable conduct and he nevertheless takes that risk then this will amount to recklessness which will preclude the defence in relation to basic intent offences.

Case in Focus

R v Clarke [2009] EWCA Crim 921

The defendant was a diabetic who was exceptionally careful at all times and responsible in ensuring that his blood sugar level remained steady. On a long drive, despite checking his blood sugar levels prior to setting off his blood sugar dropped and he became hypoglycaemic. His driving became uncontrolled and he knocked down and killed a small child. He was charged with causing death by dangerous driving. It was held that he was reckless as to becoming an automaton as he must have, even briefly, become aware of what was happening and failed to take action by pulling over. Accordingly, he was unable to rely on the defence.

Where the defendant self induces his automatism, but does so my taking a substance which is usually known to have a soporific effect then he will not be deemed to have been reckless.

Case in Focus

R v Hardie [1985] 1 WLR 64

The defendant set light to some furniture after taking some out of date Valium which was prescribed to his partner. He took the valium tablets in response to feeling stressed as his partner and him had had a big argument and he had been kicked out of their home. He was charged with arson. He sought to rely on non-insane automatism as he remembered nothing of starting the fire due to his intoxicated state. The Valium was taken for the purpose of calming the nerves and the defendant was told it would do him no harm. There was no evidence that it was known generally that taking Valium in the quantity stated would be liable to render a person aggressive unpredictable then despite the fact that the Valium was a drug and was taken deliberately, not on medical prescription, the defendant was not reckless. The drug was wholly different in kind from drugs which are liable to cause unpredictability or aggressiveness.

2.3 Insane vs. Non-Insane Automaton

The effect of a successful plea of insane automatism is a ruling of not guilty by reason of insanity. In the past this verdict meant only one thing for the defendant and that was a hospital order, under which the defendant would be detained in a psychiatric hospital for an indefinite period of time. Considering that defendants such as Hennessy who are perfectly sane individuals suffering from a very common and non-psychiatric related medical condition would have been subjected to this order it can be seen that this was very undesirable. Accordingly, once the death penalty had been abolished most defendants historically have been reluctant to plead this defence, often choosing to take a guilty verdict for a crime in law that they were not responsible for as the incarceration was preferable than being locked up in hospital with no set release date and the stigma such a detainment would carry.

Even though this compulsory hospital order is no longer in place, the special verdict carries a lot of stigma, even today, and can still result in incarceration in a psychiatric hospital if deemed necessary. The effect of this ruling in contrast to the not guilty verdict of non-insane automatism makes the distinction between the two defences crucial, with defendants seeking to argue wherever possible that an external factor caused their automatism, for example, the drugs not the disease. Consider the following case of R v T [1990] Crim LR 256. Here, the defendant was suffering from post-traumatic stress disorder following from being raped. They had committed a robbery and stabbed the victim. In pleading their defence the judge held that the post-traumatic stress was caused by the external factor of the rape and thus was automatism.

Examination Point

It can be seen from this case the obvious policy decision for not holding the defendant as being an insane automaton despite the fact the post-traumatic stress disorder was strictly constructed as an internal cause. If such an instance were to arise in a problem question consider which defence and thus the line of argument would be preferable to the defendant. Explain why this is, as showing an understanding of the real world implications and the wider context of the defences is the kind of critique that will open you up to the higher grades.

Another opportunity for critique is to discuss the artificial distinction between internal and external factor. Consider the Hennessey and Quick cases in which both defendants were essentially suffering from the same underlying cause, i.e. their diabetes, but afforded different offences. Do you think this is an acceptable position for the law to take?

4.0 Intoxication

The term intoxication is restricted to referring only to intoxication by alcohol and dangerous drugs. Dangerous drugs were defined in Hardie as those which are known to give rise of unpredictable or aggressive actions by their consumer.

4.1 Dangerous Drugs

Bailey sets out that dangerous drugs will never include prescription medication, even where the medication is not prescribed to the defendant and, or is taken to excess. In these cases the correct defence is non-insane automatism.

4.2 Involuntary Intoxication

A defendant will be classed as involuntarily intoxicated where he is not aware he is consuming an intoxicant, for example, in cases of spiked drinks.

Case in Focus

R v Allen [1988] Crim LR 698

The defendant was drinking wine but unbeknown to them the wine had an unusually high alcohol content and they became heavily intoxicated. The Court held that not knowing the precise strength of the alcohol being consumed did not make the resulting intoxication involuntary.

Hardie further establishes that a defendant will also be taken to be involuntarily intoxicated where he has voluntarily taken drugs that are usually understood to have a soporific effect but highly unusually have an opposite effect.

In these situations, the defendant will only be afforded an defence where his intoxication deprived him of the ability to form the mens rea for his committed offence. Where the defendant does still form the mens rea of the offence then he will be guilty regardless of any intoxication. In cases where drink or drug lowers the inhibitions of the defendant so that they act in a way which they would not sober, they nevertheless often have the mens rea of the crime. Consider for example the dreaded drunken phone call to an ex-partner. This phone call would not be made sober as despite wanting to, one is able to process thoughts and conclude that this is a dreadful idea! Exposed to alcohol however this process does not occur and the phone call is made. It can be seen the desire to make the phone call exists in both scenarios. The alcohol does not remove the desire, it just prevents the thought process that usually operates to prevent one following up on this desire. In these situations, the law will not excuse the behaviour of the defendant.

Case in Focus

R v Kingston [1994] 3 WLR 519

The defendant had a disagreement with another person whom subsequently employed an investigator to gain some damaging information on Kingston in order to blackmail him. The detective discovered that Kingston was homosexual who had paedophilic predilections. The defendant was not proud of this and did everything he could not to act on these urges. The investigator invited a young boy to the defendant’s room and gave him a soporific drug in his drink. The boy remembered nothing from the time of drinking the drink. The defendant was then invited to the room and also had his drink spiked. The investigator and the defendant then engaged in sexual activity with the unconscious boy with the investigator recording the events. The defendant was charged with the offence of indecent assault on the youth and sought to rely on intoxication.

The Court held that in assessing intent there is a distinction between intention at the time and a lack of memory as to what happened after the time. Involuntary intoxication where the defendant holds the requisite mens rea of the crime is no defence. The prosecution had established the defendant had the necessary mens rea for the offence and a drunken intent is still an intent.

4.3 Voluntary Intoxication

Where the defendant is voluntarily intoxicated and is charged with a specific intent offence and his intoxication means he did not form the mens rea of the offence then he will be not guilty. This is not because he has successfully pleaded the defence of intoxication but only because he has not formed the mens rea. If however, a basic intent alternative offence is available he will be convicted of that offence, for example, murder to manslaughter.

Case in Focus

R v Lipman [1970] 1 QB 152

The defendant killed his victim whilst high on LSD. He rammed a bed sheet down her throat and suffocated her. The defendant was so intoxicated that he had no knowledge of what he was doing and thus had not formed the mens rea of intention to kill. In the circumstances he was convicted of the basic intent alternative of manslaughter. 

The only caveat on this principle arises in Attorney General for Northern Ireland v Gallagher [1963] AC 349 which states that where the defendant gets intoxicated in order to commit an offence, for example ‘Dutch courage’ then there will be no reduction in liability and the specific intent charge will remain as a matter of policy.

Case in Focus

Attorney General for Northern Ireland v Gallagher [1963] AC 349

The defendant wanted to murder his wife and in preparing to do so he purchased a knife as his murder weapon of choice and a bottle of whiskey to help him build up the courage to carry out his crime. He drank most of the whiskey and became so intoxicated that there was no way that he would have been capable of forming the requisite mens rea. The Court held that in cases where a sane and sober person who forms an intention to kill and knowing that this is legally wrong, then gets so intoxicated that at the point of carrying out the act they are unable to hold that intention, no defence shall be afforded with regards to the lack of mens rea and they will be charged as if the intention was indeed held at the relevant time.

If the defendant is voluntarily intoxicated and charged with a basic intent offence then the jury must decide whether the defendant would have formed the mens rea had he been sober. If the defendant would not have formed the mens rea then he is not guilty. If the defendant would have formed the mens rea then he will be guilty and there is no requirement for the prosecution to further prove that the mens rea was actually formed. It can be seen here that the voluntary intoxication acts to inhibit the defendant by removing the burden from the prosecution to have to prove the mens rea.

4.4 Intoxicated Mistakes

If the defendant’s intoxicated mistake relates to an element of a provision of an offence which is phrased to include mistakes then his mistake will afford him a defence. In other instances this will not afford the defendant a defence.

Case in Focus

Jaggard v Dickinson [1981] QB 527

The defendant caused criminal damage to the victim’s house, believing that the house belonged to her friend who would have consented to the damage. Despite the drunken and unreasonable nature of the belief, s.5(2)(a) of the Criminal Damage Act 1971 stated that so long as the belief was honestly held the reasonableness of the belief was irrelevant and thus the defendant was found not guilty.


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