Last updated

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. [1]


The definition of manslaughter differs among legal jurisdictions.



In voluntary manslaughter, the offender had intent to kill or seriously harm, but acted "in the moment" under circumstances that could cause a reasonable person to become emotionally or mentally disturbed. Examples could include a defender killing a home invader without being placed in a life or death situation. [2] There are mitigating circumstances that reduce culpability, such as when the defendant kills only with an intent to cause serious bodily harm. [3] Voluntary manslaughter in some jurisdictions is a lesser included offense of murder. The traditional mitigating factor was provocation; however, others have been added in various jurisdictions.

The most common type of voluntary manslaughter occurs when a defendant is provoked to commit homicide. This is sometimes described as a crime of passion. [4] In most cases, the provocation must induce rage or anger in the defendant, although some cases have held that fright, terror, or desperation will suffice. [5]

Assisted suicide

Assisted suicide is suicide committed with the aid of another person, sometimes a physician.

In some places, including parts of the United States, [6] assisted suicide is punishable as manslaughter. In other countries such as Switzerland [7] and Canada, [8] and in some U.S. states, [6] as long as legal safeguards are observed, assisted suicide is legal.


Involuntary manslaughter is the killing of a human being without intent of doing so, either expressed or implied. It is distinguished from voluntary manslaughter by the absence of intention. It is normally divided into two categories, constructive manslaughter and criminally negligent manslaughter, both of which involve criminal liability.


Constructive manslaughter is also referred to as "unlawful act" manslaughter. [9] It is based on the doctrine of constructive malice, whereby the malicious intent inherent in the commission of a crime is considered to apply to the consequences of that crime. It occurs when someone kills, without intent, in the course of committing an unlawful act. The malice involved in the crime is transferred to the killing, resulting in a charge of manslaughter.

For example, a person who fails to stop at a red traffic light while driving a vehicle and hits someone crossing the street could be found to intend or be reckless as to assault or criminal damage (see DPP v Newbury [10] ). There is no intent to kill, and a resulting death would not be considered murder, but would be considered involuntary manslaughter. The accused's responsibility for causing death is constructed from the fault in committing what might have been a minor criminal act. Reckless driving or reckless handling of a potentially lethal weapon may result in a death that is deemed manslaughter. The DPP v Newbury case had redefined the meaning of murder in the Australian constitution, and reformed in order to include a mens rea assessment.

Involuntary manslaughter may be distinguished from accidental death. A person who is driving carefully, but whose car nevertheless hits a child darting out into the street, has not committed manslaughter. A person who pushes off an aggressive drunk, who then falls and dies, has probably not committed manslaughter, although in some jurisdictions it may depend whether "excessive force" was used or other factors.

As manslaughter is not defined by legislation in Australia, common law decisions provide the basis for determining whether an act resulting in death amounts to manslaughter by unlawful and dangerous act. [11] To be found guilty of manslaughter by an unlawful and dangerous act, the accused must be shown to have committed an unlawful act which is contrary to the criminal law, [12] and that a reasonable person in the position of the accused would have known that by their act, they were exposing the victim to an "appreciable risk of serious injury". [13]

Criminally negligent

Criminally negligent manslaughter is variously referred to as criminally negligent homicide in the United States, and gross negligence manslaughter in England and Wales. In Scotland and some Commonwealth of Nations jurisdictions the offence of culpable homicide might apply.

It occurs where death results from serious negligence, or, in some jurisdictions, serious recklessness. A high degree of negligence is required to warrant criminal liability. [14] A related concept is that of willful blindness, which is where a defendant intentionally puts themselves in a position where they will be unaware of facts which would render them liable.

Criminally negligent manslaughter occurs where there is an omission to act when there is a duty to do so, or a failure to perform a duty owed, which leads to a death. The existence of the duty is essential because the law does not impose criminal liability for a failure to act unless a specific duty is owed to the victim. It is most common in the case of professionals who are grossly negligent in the course of their employment. An example is where a doctor fails to notice a patient's oxygen supply has disconnected and the patient dies (R v Adomako and R v Perreau). [15] Another example could be leaving a child locked in a car on a hot day.[ citation needed ]

Vehicular and intoxicated

In some jurisdictions, such as some U.S. States, [16] [17] [18] [19] there exists the specific crime of vehicular or intoxication manslaughter. An equivalent in Canada is causing death by criminal negligence [20] under the Criminal Code, punishable by a maximum penalty of life imprisonment.

On the mens rea , or state of mind, or the circumstances under which the killing occurred (mitigating factors), manslaughter is usually broken down into two distinct categories: voluntary manslaughter and involuntary manslaughter . [21] However, this is not the case in all jurisdictions, for example, in the U.S. state of Florida. [22]

In some jurisdictions, [23] such as the U.K., [24] Canada, [25] [26] and some Australian states, [27] "adequate provocation" may be a partial defense to a charge of murder, which, if accepted by the jury, would convert what might otherwise have been a murder charge into manslaughter.

National standards


In Australia, specifically New South Wales, manslaughter is referred to, however not defined, in the Crimes Act 1900 (NSW). [28]

Manslaughter exists in two forms in New South Wales: Voluntary or Involuntary Manslaughter. In New South Wales, in cases of voluntary manslaughter, both the actus reus (literally guilty act) and mens rea (literally guilty mind) for murder are proven but the defendant has a partial defence, such as extreme provocation or diminished responsibility. [29] [11] :[51]–[65] In cases of involuntary manslaughter, the actus reus for murder is present but there is insufficient mens rea to establish such a charge.

There are two categories of involuntary manslaughter at common law: manslaughter by unlawful and dangerous act and manslaughter by criminal negligence. The authority for the actus reus and mens rea of involuntary manslaughter by an unlawful and dangerous act is the High Court of Australia case of Wilson v R. [30] This case determined that the act that caused the death must breach the criminal law and that the act must carry an appreciable risk of serious injury (actus reus). Regarding the mens rea, the court held that the accused must intend to commit the unlawful act and that a reasonable person in the position of the accused would have realised or recognised that the act carried an appreciable risk of serious injury. Manslaughter by criminal negligence, on the other hand, finds its authority in the Victorian case of Nydam v R, [31] confirmed by the High Court of Australia in R v Lavender [14] and Burns v R. [32] In Nydam v R, [31] the Court described the office at [445] in the following terms:

In order to establish manslaughter by criminal negligence, it is sufficient if the prosecution shows that the act which caused the death was done by the accused consciously and voluntarily, without any intention of causing death or grievous bodily harm but in circumstances which involved such a great falling short of the standard of care which a reasonable man would have exercised and which involved such a high risk that death or grievous bodily harm would follow that the doing of the act merited criminal punishment. [31]


Canadian law distinguishes between justifiable, accidental and culpable homicide. If a death is deemed a culpable homicide, it generally falls under one of four categories (first-degree murder, second-degree murder, manslaughter, and infanticide). [33]

Canadian law defines manslaughter as "a homicide committed without the intention to cause death, although there may have been an intention to cause harm". There are two broad categories of manslaughter: unlawful act, and criminal negligence.

Unlawful act is when a person commits a crime that unintentionally results in the death of another person. [34]

Criminal negligence is when the homicide was the result of an act that showed wanton or reckless disregard for the lives of others. [35]


In English law, manslaughter is a less serious offence than murder. In England and Wales, the usual practice is to prefer a charge of murder, with the judge or defence able to introduce manslaughter as an option (see lesser included offence). The jury then decides whether the defendant is guilty or not guilty of either murder or manslaughter. Manslaughter may be either voluntary or involuntary, depending on whether the accused has the required mens rea for murder.

The Homicide Act 1957 and Coroners and Justice Act 2009 are relevant acts.

Voluntary manslaughter occurs when the defendant avails themself of the three statutory defenses described in the Homicide Act 1957 (provocation, diminished responsibility, and a suicide pact).

Involuntary manslaughter occurs when the agent has no intention (mens rea) of committing murder, but caused the death of another through recklessness or criminal negligence. The crime of involuntary manslaughter can be subdivided into two main categories: constructive manslaughter and gross negligence manslaughter.

United States

Manslaughter is a crime in the United States. Definitions can vary among jurisdictions, but the U.S. follows the general principle that manslaughter involves causing the death of another person in a manner less culpable than murder, and observes the distinction between voluntary and involuntary manslaughter. [36]

Civil law

Some civil law jurisdictions, such as the French Code, use "murder" or "involuntary homicide" to cover the crime of manslaughter, and reserve "assassination" for the crime of premeditated murder. [37]

Historical distinction from murder

A legal distinction between intentional and unintentional homicide was introduced in Athenian law in 409 BC, [38] when the legal code of Draco indicated that intentional homicide (hekousios phonos or phonos ek pronoias) was punishable by death. The language is ambiguous as to unintentional homicide (akousios phonos), but it may have been punishable by exile. [39] [40] However, academic David D Phillips says that these categories "do not correspond to the common-law categories of murder and manslaughter either in their original significance or in their present definitions", because under Athenian law intentional homicide would include both murder and voluntary manslaughter. [40]

Anglo-Saxon law recognised particular degrees of homicide, with the worst being forsteall (killing by ambush). [41] Murdra was a separate type of aggravated (secret) homicide under Anglo-Saxon law; William the Conqueror defined it narrowly as a fine that would be charged on a hundred following the slaying of a foreigner (originally a Norman, but intermarriage would end the distinction between Normans and English by the 13th century). [41] By 1348, the association between murdrum and malice aforethought emerged. [41]

"Manslaughter" as a general term for homicide was in use in medieval England by the late 1200s, during which time a distinction was forming between homicide committed in necessary self-defence (pardoned without culpability) and homicide committed by accident (pardoned but with moral blame). [41] From 1390, homicide in necessary self-defence or by misadventure became "pardons of course", meaning that the Chancery would issue them by default. [41] Homicide in necessary self-defence would later be acquitted, rather than pardoned. [41] The use of "manslaughter" to cover homicides other than murder emerged by 1547, in a statute. [41] Edward Coke confirms this distinction in The Third Part of the Institutes of the Laws of England, which remains "the authoritative starting point for any examination of the law of homicide" in the United Kingdom and other common law countries. [42]

See also

Related Research Articles

Murder Unlawful killing of a human

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 Killing of a human by another human

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."

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.

In criminal law, criminal negligence is a surrogate state of mind required to constitute a conventional offense. It is not, strictly speaking, a mens rea because it refers to an objective standard of behaviour expected of the defendant and does not refer to their mental state.

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.

Corporate manslaughter is a criminal offence in English law, being an act of homicide committed by a company or organisation. In general, in English criminal law, a juristic person is in the same position as a natural person, and may be convicted for committing many offences. The Court of Appeal confirmed in one of the cases following the Herald of Free Enterprise disaster that a company can, in principle, commit manslaughter, although all defendants in that case were acquitted.

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.

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.

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.

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.

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.

In Australia, murder, like most criminal law, is defined by State legislation.

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.

The categorical test is a legal standard for determining whether there has been adequate provocation to reduce a murder charge to voluntary manslaughter. Traditionally, the mens rea for murder was malice aforethought. While murder and voluntary manslaughter are both intentional homicides, adequate provocation mitigates a defendant's culpability. Adequate provocation is a legal requirement for a murder charge to be reduced to voluntary manslaughter. The test for adequate provocation varies across jurisdictions and has changed over time. The categorical approach is based on common law principles, but most courts today apply less restrictive tests, such as the extreme emotional disturbance test in Model Penal Code jurisdictions.


  1. Ehrenberg, Victor (1973) [1968]. From Solon to Socrates: Greek History and Civilization During the 6th and 5th Centuries BCE (Second ed.). New York: Routledge. p. 57. ISBN   978-0-415-04024-2 . Retrieved 31 December 2015.
  2. Weber, Jack K. (1 July 1981). "Some Provoking Aspects of Voluntary Manslaughter Law". Anglo-American Law Review. 10 (3): 159. doi:10.1177/147377958101000302. S2CID   157180471.
  3. Allen, Michael (2013). Textbook on Criminal Law (12 ed.). Oxford, U.K.: Oxford University Press. ISBN   9780199669295 . Retrieved 10 September 2017.
  4. Dressler, Joshua (Summer 1982). "Rethinking heat of passion: A defense in search of a rationale". Journal of Criminal Law and Criminology. 73 (2): 421–470. doi:10.2307/1143104. JSTOR   1143104. Archived from the original on 11 September 2017. Retrieved 10 September 2017.
  5. Barkan, Steven E.; Bryjak, George J. (2009). Myths and Realities of Crime and Justice: What Every American Should Know. Massachusetts: Jones & Bartlett Publishers. ISBN   9780763755744 . Retrieved 10 September 2017.
  6. 1 2 "Patients Rights Council". Assisted Suicide Laws in the United States. 6 January 2017. Archived from the original on 11 September 2017. Retrieved 10 September 2017.
  7. Sarchet, Penny (22 September 2014). "Tourism to Switzerland for assisted suicide is growing, often for nonfatal diseases". The Washington Post . Archived from the original on 11 September 2017. Retrieved 10 September 2017.
  8. "Assisted Suicide". End of Life Law & Policy in Canada. Health Law Institute, Dalhousie University. Archived from the original on 11 September 2017. Retrieved 10 September 2017.
  9. "Involuntary Manslaughter". IPSA LOQUITUR. Retrieved 23 October 2019.
  10. [1977] AC 500
  11. 1 2 Lane v R [2013] NSWCCA 317 at [46], Court of Criminal Appeal (NSW,Australia).
  12. Wilson v R [1992] HCA 31 , (1992) 174 CLR 313 per Brennan, Deane and Dawson JJ at [2], High Court (Australia).
  13. Wilson v R [1992] HCA 31 , (1992) 174 CLR 313 per Mason CJ, Toohey, Gaudron and McHugh JJ at [48], High Court (Australia).
  14. 1 2 R v Lavender [2005] HCA 37 , (2005) 222 CLR 67 at [17], [60], [72], [136](4 August 2005), High Court (Australia).
  15. R v Adomako [1994] UKHL 6 , [1994] 3 WLR 288, House of Lords (UK).
  16. See, e.g., "New York Penal Code, Sec. 125.13. Vehicular manslaughter in the first degree". New York State Senate. Archived from the original on 11 September 2017. Retrieved 10 September 2017.
  17. See also "California Penal Code, Sec. 192(c)". California Legislative Information. California Legislature. Archived from the original on 12 September 2017. Retrieved 10 September 2017.
  18. See also "Wisconsin Statutes, Sec. 940.09. Homicide by intoxicated use of vehicle or firearm". Wisconsin State Legislature. Archived from the original on 11 September 2017. Retrieved 10 September 2017.
  19. See also "Texas Penal Code, Sec. 49.08. Intoxication Manslaughter". Texas State Legislature. Archived from the original on 11 September 2017. Retrieved 10 September 2017.
  20. "Criminal Code (R.S.C., 1985, c. C-46), Sec. 220, Causing Death by Criminal Negligence". Justice Laws Website. Government of Canada. Archived from the original on 11 September 2017. Retrieved 10 September 2017.
  21. "Manslaughter". Wex. Cornell Law School. July 2009. Archived from the original on 11 September 2017. Retrieved 29 June 2017.
  22. "Florida Statutes, Sec. 782.07. Manslaughter". Online Sunshine. State of Florida. Archived from the original on 11 September 2017. Retrieved 10 September 2017.
  23. Berman, Mitchell N. (2011). "Provocation as a Partial Justification and Partial Excuse". Penn Law: Legal Scholarship Repository. University of Pennsylvania Law School. Archived from the original on 16 April 2016. Retrieved 10 September 2017.
  24. "Loss Of Control And Diminished Responsibility". Oxbridge Notes. Archived from the original on 11 September 2017. Retrieved 10 September 2017.
  25. Knoll, Pat (14 April 2015). "CED, an Overview of the Law — Criminal Law – Defences: Provocation". WestLaw Next Canada. Thomson Reuters. Archived from the original on 11 September 2017. Retrieved 10 September 2017.
  26. Fine, Sean (25 October 2013). "Supreme Court dismisses 'provoked' defence claim in murder cases". Globe and Mail. Archived from the original on 5 June 2018. Retrieved 10 September 2017.
  27. "Provocation as a Defence to Murder" (PDF). National Criminal Justice Reference Service. Government of Australia. 1979. Archived (PDF) from the original on 16 February 2017. Retrieved 10 September 2017.
  28. Crimes Act 1900 (NSW) s 18 Murder and manslaughter defined.
  29. Crimes Act 1900 (NSW) s 23 and 23A (NSW).
  30. Wilson v R [1992] HCA 31 , (1992) 174 CLR 313, High Court (Australia).
  31. 1 2 3 Nydam v R [1977] VicRp 50 , [1977] VR 430(17 December 1976), Supreme Court (Vic,Australia).
  32. Burns v R [2012] HCA 35 , (2012) 246 CLR 334 per French CJ at [19](14 September 2012), High Court (Australia).
  33. "Consolidated federal laws of canada, Criminal Code". 27 August 2021.
  34. "Murder vs. manslaughter". CBC News. 24 February 2012. Retrieved 30 November 2021.
  35. "Murder vs. Manslaughter". CBC News. 27 February 2012. Archived from the original on 12 September 2017. Retrieved 10 September 2017.
  36. Larson, Aaron (17 October 2016). "What Are Homicide and Murder". Archived from the original on 10 September 2017. Retrieved 10 September 2017.
  37. "Criminal Code of the French Republic". 2005. Archived from the original on 2018-02-05.
  38. Volonaki, Eleni (2000). ""Apagoge" in Homicide Cases" (PDF). Dike. 3.
  39. Gagarin, Michael (1981). Drakon and early Athenian homicide law . New York: Yale U.P. ISBN   978-0300026276.
  40. 1 2 Phillips, David D. "Phonos as a Term of Athenian Law: "Homicide" or "Killing," Not "Murder/Manslaughter"" (PDF). The Classical Association of the Middle West and South.
  41. 1 2 3 4 5 6 7 "Brown, Bernard --- "The Emergence Of The Psychical Test Of Guilt In Homicide, 1200-1550" [1959] UTasLawRw 4; (1959) 1(2) University of Tasmania Law Review 231". Retrieved 2018-12-04.
  42. "Waller, Louis --- "The Tracy Maund Memorial Lecture: Any Reasonable Creature in Being" [1987] MonashULawRw 2; (1987) 13(1) Monash University Law Review 37". Retrieved 2018-12-04.