Double jeopardy is a procedural defence that prevents an accused person from being tried again on the same charges and on the same facts, following a valid acquittal or conviction. As described by the U.S. Supreme Court in its unanimous decision concerning Ball v. United States 163 U.S. 662 (1896), one of its earliest cases dealing with double jeopardy, "the prohibition is not against being twice punished, but against being twice put in jeopardy; and the accused, whether convicted or acquitted, is equally put in jeopardy at the first trial."
The M'Naghten rule is any variant of the 1840s jury instruction in a criminal case when there is a defense 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.
Mens rea is the mental element of a person's intention to commit a crime; or knowledge that one's action or lack of action would cause a crime to be committed. It is a necessary element of many crimes.
De minimis is a Latin expression meaning "about minimal things", normally in the locutions de minimis non curat praetor or de minimis non curat lex a legal doctrine by which a court refuses to consider trifling matters. Queen Christina of Sweden (r. 1633–1654) favoured the similar Latin adage, aquila non capit muscās.
In criminal law, entrapment is a practice whereby a law enforcement agent or agent of the state induces a person to commit a criminal offense that the person would have otherwise been unlikely or unwilling to commit. It "is the conception and planning of an offense by an officer or agent, and the procurement of its commission by one who would not have perpetrated it except for the trickery, persuasion or fraud of the officer or state agent."
The rule of felony murder is a legal doctrine in some common law jurisdictions that broadens the crime of murder: when an offender kills in the commission of a dangerous or enumerated crime, the offender, and also the offender's accomplices or co-conspirators, may be found guilty of murder.
Reasonable doubt is a term used in jurisdiction of common law countries. Evidence that is beyond reasonable doubt is the standard of evidence required to validate a criminal conviction in most adversarial legal systems.
An attempt to commit a crime occurs if a criminal has an intent to commit a crime and takes a substantial step toward completing the crime, but for reasons not intended by the criminal, the final resulting crime does not occur. Attempt to commit a particular crime is a crime, usually considered to be of the same or lesser gravity as the particular crime attempted. Attempt is a type of inchoate crime, a crime that is not fully developed. The crime of attempt has two elements, intent and some conduct toward completion of the crime.
R v Creighton, [1993] 3 S.C.R. 3 is a landmark case from the Supreme Court of Canada where the Court found that the standard for criminal liability for some offences can be lowered and not offend the Charter. This case marked the last in a series of cases, beginning with R. v. Tutton, discussing the use of an objective standard for determining mens rea in criminal offences.
R v Martineau, [1990] 2 SCR 633 is a leading Supreme Court of Canada case on the mens rea requirement for murder.
Causation is the "causal relationship between the defendant's conduct and end result". In other words, causation provides a means of connecting conduct with a resulting effect, typically an injury. In criminal law, it is defined as the actus reus from which the specific injury or other effect arose and is combined with mens rea to comprise the elements of guilt. Causation only applies where a result has been achieved and therefore is immaterial with regard to inchoate offenses.
In criminal law, intent is a subjective state of mind that must accompany the acts of certain crimes to constitute a violation. A more formal, generally synonymous legal term is scienter: intent or knowledge of wrongdoing.
Reibl v Hughes [1980] 2 S.C.R. 880 is a leading decision of the Supreme Court of Canada on negligence, medical malpractice, informed consent, the duty to warn, and causation.
Morguard Investments Ltd v De Savoye, [1990] 3 SCR 1077 is the leading decision of the Supreme Court of Canada on the enforcement of extraprovincial judgments. The Court held that the standard for enforcing a default judgment from a different province is not the same as if it were from another country; rather the Court adopts the test from Indyka v Indyka, [1969] 1 AC 33 (HL) and the Moran v Pyle National (Canada) Ltd, [1975] 1 SCR 393 where there must be a "real and substantial connection" between the petitioner and the country or territory exercising jurisdiction.
Murder is an offence under the common law of England and Wales. It is considered the most serious form of homicide, in which one person kills another with the intention to cause either death or serious injury unlawfully. The element of intentionality was originally termed malice aforethought although it required neither malice nor premeditation.
R v Harbottle, [1993] 3 SCR 306 is a Canadian criminal law case decided by the Supreme Court of Canada on the standard of causation required in order for an accused to be convicted of first degree murder under section 231(5) of the Criminal Code. The Court held that the standard for this provision must be strict requiring a "substantial and integral cause". On the facts, the Court found that Harbottle's conduct in holding the victim's legs while she was strangled to death was sufficient to be a substantial and integral cause. This standard does not apply to all first degree murder, where the standard articulated in R v Nette applies.
The "born alive" rule is a common law legal principle that holds that various criminal laws, such as homicide and assault, apply only to a child that is "born alive". U.S. courts have overturned this rule, citing recent advances in science and medicine; and in several states, feticide statutes have been explicitly framed or amended to include fetuses in utero. Abortion in Canada is still governed by the born alive rule, as courts continue to hold to its foundational principles. In 1996, the Law Lords confirmed that the rule applied in English law but that alternative charges existed in lieu, such as a charge of unlawful or negligent manslaughter instead of murder.
Fault, as a legal term, refers to legal blameworthiness and responsibility in each area of law. It refers to both the actus reus and the mental state of the defendant. The basic principle is that a defendant should be able to contemplate the harm that his actions may cause, and therefore should aim to avoid such actions. Different forms of liability employ different notions of fault, in some there is no need to prove fault, but the absence of it.
Murder in Canada is defined as a culpable homicide with specific intentions. It is defined by the Criminal Code, a statute passed by the Parliament of Canada and which applies uniformly across Canada.
