Murder is the unlawful killing of another human without justification or valid excuse, especially the unlawful killing of another human with malice aforethought. This state of mind may, depending upon the jurisdiction, distinguish murder from other forms of unlawful homicide, such as manslaughter. Manslaughter is killing committed in the absence of malice, brought about by reasonable provocation, or diminished capacity. Involuntary manslaughter, where it is recognized, is a killing that lacks all but the most attenuated guilty intent, recklessness.
Homicide occurs when a person kills another person. A homicide requires only a volitional act or omission that causes the death of another, and thus a homicide may result from accidental, reckless, or negligent acts even if there is no intent to cause harm. Homicides can be divided into many overlapping legal categories, including murder, manslaughter, justifiable homicide, assassination, killing in war, euthanasia, and capital punishment, depending on the circumstances of the death. These different types of homicides are often treated very differently in human societies; some are considered crimes, while others are permitted or even ordered by the legal system.
In law, provocation is when a person is considered to have committed a criminal act partly because of a preceding set of events that might cause a reasonable individual to lose self control. This makes them less morally culpable than if the act was premeditated (pre-planned) and done out of pure malice. It "affects the quality of the actor's state of mind as an indicator of moral blameworthiness."
In criminal law, diminished responsibility is a potential defense by excuse by which defendants argue that although they broke the law, they should not be held fully criminally liable for doing so, as their mental functions were "diminished" or impaired.
The concept of justifiable homicide in criminal law is a defense to culpable homicide. Generally, there is a burden of production of exculpatory evidence in the legal defense of justification. In most countries, a homicide is justified when there is sufficient evidence to disprove the alleged criminal act or wrongdoing. The key to this legal defense is that it was reasonable for the subject to believe that there was an imminent and otherwise unavoidable danger of death or grave bodily harm to the innocent by the deceased when they committed the homicide. A homicide in this instance is blameless.
Vehicular homicide is a crime that involves the death of a person other than the driver as a result of either criminally negligent or murderous operation of a motor vehicle.
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.
Lemuel Shaw was an American jurist who served as Chief Justice of the Massachusetts Supreme Judicial Court (1830–1860). Prior to his appointment he also served for several years in the Massachusetts House of Representatives and as a state senator. In 1847, Shaw became the father-in-law of author Herman Melville. He ruled on prominent cases involving slavery, segregation, and religion.
Culpable homicide is a categorisation of certain offences in various jurisdictions within the Commonwealth of Nations which involves the illegal killing of a person either with or without an intention to kill depending upon how a particular jurisdiction has defined the offence. Unusually for those legal systems which have originated or been influenced during rule by the United Kingdom, the name of the offence associates with Scots law rather than English law.
Malice aforethought is the "premeditation" or "predetermination" required as an element of some crimes in some jurisdictions and a unique element for first-degree or aggravated murder in a few. Insofar as the term is still in use, it has a technical meaning that has changed substantially over time.
Voluntary manslaughter is the killing of a human being in which the offender acted during the heat of passion, under circumstances that would cause a reasonable person to become emotionally or mentally disturbed to the point that they cannot reasonably control their emotions. Voluntary manslaughter is one of two main types of manslaughter, the other being involuntary manslaughter.
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. Baker, chapter 14 states that many killings done with a high degree of subjective recklessness were treated as murder from the 12th century right through until the 1974 decision in DPP v Hyam.
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.
Manslaughter is a common law legal term for homicide considered by law as less culpable than murder. The distinction between murder and manslaughter is sometimes said to have first been made by the ancient Athenian lawmaker Draco in the 7th century BC.
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.
In the United States, the law for murder varies by jurisdiction. In most US jurisdictions there is a hierarchy of acts, known collectively as homicide, of which first-degree murder and felony murder are the most serious, followed by second-degree murder and, in a few states, third-degree murder, followed by voluntary manslaughter and involuntary manslaughter which are not as serious, followed by reckless homicide and negligent homicide which are the least serious, and ending finally in justifiable homicide, which is not a crime. However, because there are at least 52 relevant jurisdictions, each with its own criminal code, this is a considerable simplification.
Responsibility for criminal law and criminal justice in the United States is shared between the states and the federal government.
English law contains homicide offences – those acts involving the death of another person. For a crime to be considered homicide, it must take place after the victim's legally recognised birth, and before their legal death. There is also the usually uncontroversial requirement that the victim be under the "Queen's peace". The death must be causally linked to the actions of the defendant. Since the abolition of the year and a day rule, there is no maximum time period between any act being committed and the victim's death, so long as the former caused the latter.
Manslaughter is a crime in the United States. Definitions can vary among jurisdictions, but manslaughter is invariably the act of causing the death of another person in a manner less culpable than murder. Three types of unlawful killings constitute manslaughter. First, there is voluntary manslaughter which is an intentional homicide committed in "sudden heat of passion" as the result of adequate provocation. Second, there is the form of involuntary manslaughter which is an unintentional homicide that was committed in a criminally negligent manner. Finally, there is the form of involuntary manslaughter which is an unintentional homicide that occurred during the commission or attempted commission of an unlawful act which does not amount to a felony.
