The M'Naghten rule is any variant of the 1840s jury instruction in a criminal case when there is a defence of insanity:
that 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 the mind, as 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.
In Western jurisprudence, concurrence is the apparent need to prove the simultaneous occurrence of both actus reus and mens rea, to constitute a crime; except in crimes of strict liability. In theory, if the actus reus does not hold concurrence in point of time with the mens rea then no crime has been committed.
In criminal law, automatism is a rarely used criminal defence. It is one of the mental condition defences that relate to the mental state of the defendant. Automatism can be seen variously as lack of voluntariness, lack of culpability (unconsciousness) or excuse. Automatism means that the defendant was not aware of his or her actions when making the particular movements that constituted the illegal act.
In criminal law, consent may be used as an excuse and prevent the defendant from incurring liability for what was done.
Self-defence is a defence permitting reasonable force to be used to defend one's self or another. This defence arises both from common law and the Criminal Law Act 1967. Self-defence is a justification defence rather than an excuse.
In the criminal law of Australia, self-defence is a legal defence to a charge of causing injury or death in defence of the person or, to a limited extent, property, or a partial defence to murder if the degree of force used was excessive.
In English law, the defence of necessity recognises that there may be situations of such overwhelming urgency that a person must be allowed to respond by breaking the law. There have been very few cases in which the defence of necessity has succeeded, and in general terms there are very few situations where such a defence could even be applicable. The defining feature of such a defence is that the situation is not caused by another person and that the accused was in genuine risk of immediate harm or danger.
Duress in English law is a complete common law defence, operating in favour of those who commit crimes because they are forced or compelled to do so by the circumstances, or the threats of another. The doctrine arises not only in criminal law but also in civil law, where it is relevant to contract law and trusts law.
In English law, provocation was a mitigatory defence to murder which had taken many guises over generations many of which had been strongly disapproved and modified. In closing decades, in widely upheld form, it amounted to proving a reasonable total loss of control as a response to another's objectively provocative conduct sufficient to convert what would otherwise have been murder into manslaughter. It only applied to murder. It was abolished on 4 October 2010 by section 56(1) of the Coroners and Justice Act 2009, but thereby replaced by the superseding—and more precisely worded—loss of control defence.
In English law, diminished responsibility is one of the partial defenses that reduce the offense from murder to manslaughter if successful. This allows the judge sentencing discretion, e.g. to impose a hospital order under section 37 of the Mental Health Act 1983 to ensure treatment rather than punishment in appropriate cases. Thus, when the actus reus of death is accompanied by an objective or constructive version of mens rea, the subjective evidence that the defendant did intend to kill or cause grievous bodily harm because of a mental incapacity will partially excuse his conduct. Under s.2(2) of the Homicide Act 1957 the burden of proof is on the defendant to the balance of probabilities. The M'Naghten Rules lack a volitional limb of "irresistible impulse"; diminished responsibility is the volitional mental condition defense in English criminal law.
In the English law of homicide, manslaughter is a less serious offence than murder, the differential being between levels of fault based on the mens rea or by reason of a partial defence. In England and Wales, a common practice is to prefer a charge of murder, with the judge or defence able to introduce manslaughter as an option. The jury then decides whether the defendant is guilty or not guilty of either murder or manslaughter. On conviction for manslaughter, sentencing is at the judge's discretion, whereas a sentence of life imprisonment is mandatory on conviction for murder. Manslaughter may be either voluntary or involuntary, depending on whether the accused has the required mens rea for murder.
Criminal damage in English law was originally a common law offence. The offence was largely concerned with the protection of dwellings and the food supply, and few sanctions were imposed for damaging personal property. Liability was originally restricted to the payment of damages by way of compensation.
R v Quick [1973] QB 910 is an English criminal case, as to sane automatism and the sub-category of self-inducement of such a state. The court ruled that it may not be used as a defence if the defendant's loss of self-control was on the part of negligence in consuming or not consuming something which someone ought to but the jury must be properly directed so as to make all relevant findings of fact. The ruling stresses that automatism is usually easily distinct from insanity, in the few cases where the lines are blurred it is a complex problem for prosecutors and mental health professionals.
R v Bailey is a 1983 decision of the Court of Appeal of England and Wales considering criminal responsibility as to non-insane automatism. The broad questions addressed were whether a hampered state of mind, which the accused may have a legal and moral duty to lessen or avoid, gave him a legal excuse for his actions; and whether as to any incapacity there was strong countering evidence on the facts involved. The court ruled that the jury had been misdirected as to the effect of a defendant's mental state on his criminal liability. However, Bailey's defence had not been supported by sufficient evidence to support an acquittal and his appeal was dismissed.
English criminal law concerns offences, their prevention and the consequences, in England and Wales. Criminal conduct is considered to be a wrong against the whole of a community, rather than just the private individuals affected. The state, in addition to certain international organisations, has responsibility for crime prevention, for bringing the culprits to justice, and for dealing with convicted offenders. The police, the criminal courts and prisons are all publicly funded services, though the main focus of criminal law concerns the role of the courts, how they apply criminal statutes and common law, and why some forms of behaviour are considered criminal. The fundamentals of a crime are a guilty act and a guilty mental state. The traditional view is that moral culpability requires that a defendant should have recognised or intended that they were acting wrongly, although in modern regulation a large number of offences relating to road traffic, environmental damage, financial services and corporations, create strict liability that can be proven simply by the guilty act.
In the field of criminal law, there are a variety of conditions that will tend to negate elements of a crime, known as defenses. The label may be apt in jurisdictions where the accused may be assigned some burden before a tribunal. However, in many jurisdictions, the entire burden to prove a crime is on the prosecution, which also must prove the absence of these defenses, where implicated. In other words, in many jurisdictions the absence of these so-called defenses is treated as an element of the crime. So-called defenses may provide partial or total refuge from punishment.
Intoxication in English law is a circumstance which may alter the capacity of a defendant to form mens rea, where a charge is one of specific intent, or may entirely negate mens rea where the intoxication is involuntary. The fact that a defendant is intoxicated in the commission of a crime — whether voluntarily or not — has never been regarded as a full defence to criminal proceedings. Its development at common law has been shaped by the acceptance that intoxicated individuals do not think or act as rationally as they would otherwise, but also by a public policy necessity to punish individuals who commit crimes.
Criminal law is a system of laws that is connected with crimes and punishments of an individual who commits crimes. In comparison, civil law is where the case argues their issues with one entity to another entity with support of the law. Crimes can vary in definition by jurisdiction but the basis for a crime are fairly consistent regardless.
South African criminal law is the body of national law relating to crime in South Africa. In the definition of Van der Walt et al., a crime is "conduct which common or statute law prohibits and expressly or impliedly subjects to punishment remissible by the state alone and which the offender cannot avoid by his own act once he has been convicted." Crime involves the infliction of harm against society. The function or object of criminal law is to provide a social mechanism with which to coerce members of society to abstain from conduct that is harmful to the interests of society.
Peterson v Minister of Safety and Security is an important case in South African criminal law. For the appellant appeared J Whitehead SC, instructed by JL Martinson & Company, Cape Town; for the respondents, A Schippers SC and S O'Brien, instructed by the State Attorney, Cape Town.
