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Murder is the unlawful killing, with malice aforethought, of another human, and generally this premeditated state of mind distinguishes murder from other forms of unlawful homicide (such as manslaughter).
Most societies both present and in antiquity have considered murder a most serious crime worthy of the harshest of punishment, under the justification that commission of murder is highly detrimental to good order within society. In most countries, a person convicted of murder is typically given a long prison sentence, possibly a life sentence where permitted, and in some countries, the death penalty may be imposed for such an act – though this practice is becoming less common.
- Common and sharia law 1.1
- General 1.2.1
- Specific to certain countries 1.2.2
- Victim 1.3
Mitigating circumstances 1.4
- Insanity 1.4.1
- Post-partum depression 1.4.2
- Unintentional 1.4.3
- Diminished capacity 1.4.4
- Aggravating circumstances 1.5
- Year-and-a-day rule 1.6
Origins and history 2
- Etymology 2.1
- History 3.1
Specific murder law 4
- Degrees of murder by country 4.1
- See also 5
- References 6
- Bibliography 7
- External links 8
when a person, of sound memory and discretion, unlawfully kills any reasonable creature in being and under the king's peace, with malice aforethought, either express or implied.
The elements of common law murder are:
- of a human
- by another human
- with malice aforethought.
The Unlawful – This distinguishes murder from killings that are done within the boundaries of law, such as capital punishment, justified self-defense, or the killing of enemy combatants by lawful combatants as well as causing collateral damage to non-combatants during a war.
Killing – At common law life ended with cardiopulmonary arrest – the total and permanent cessation of blood circulation and respiration. With advances in medical technology courts have adopted irreversible cessation of all brain function as marking the end of life.
by another human – At early common law, suicide was considered murder. The requirement that the person killed be someone other than the perpetrator excluded suicide from the definition of murder.
with malice aforethought – Originally malice aforethought carried its everyday meaning – a deliberate and premeditated (prior intent) killing of another motivated by ill will. Murder necessarily required that an appreciable time pass between the formation and execution of the intent to kill. The courts broadened the scope of murder by eliminating the requirement of actual premeditation and deliberation as well as true malice. All that was required for malice aforethought to exist is that the perpetrator act with one of the four states of mind that constitutes "malice."
The four states of mind recognized as constituting "malice" are:
Under state of mind (i), intent to kill, the deadly weapon rule applies. Thus, if the defendant intentionally uses a deadly weapon or instrument against the victim, such use authorizes a permissive inference of intent to kill. In other words, "intent follows the bullet." Examples of deadly weapons and instruments include but are not limited to guns, knives, deadly toxins or chemicals or gases and even vehicles when intentionally used to harm one or more victims.
Under state of mind (iii), an "abandoned and malignant heart", the killing must result from defendant's conduct involving a reckless indifference to human life and a conscious disregard of an unreasonable risk of death or serious bodily injury. An example of this is a 2007 law in California where an individual could be convicted of third-degree murder if he or she kills another person while driving under the influence of alcohol, drugs, or controlled substances.
Under state of mind (iv), the felony-murder doctrine, the felony committed must be an inherently dangerous felony, such as burglary, arson, rape, robbery or kidnapping. Importantly, the underlying felony cannot be a lesser included offense such as assault, otherwise all criminal homicides would be murder as all are felonies.
Many jurisdictions divide murder by degrees. The most common divisions are between first and second degree murder. Generally, second degree murder is common law murder, and first degree is an aggravated form. The aggravating factors of first degree murder are a specific intent to kill, premeditation, and deliberation. In addition, murder committed by acts such as strangulation, poisoning, or lying in wait are also treated as first degree murder.
As with most legal terms, the precise definition of murder varies between jurisdictions and is usually codified in some form of legislation. Even when the legal distinction between murder and manslaughter is clear, it is not unknown for a jury to find an defendant to murder guilty of the lesser offence. The jury might sympathise with the defendant (e.g. in a crime of passion, or in the case of a bullied victim who kills their tormentor), and the jury may wish to protect the defendant from a sentence of life imprisonment or execution.
Common and sharia law
According to Blackstone, English common law identified murder as a public wrong. At common law, murder is considered to be malum in se, that is an act which is evil within itself. An act such as murder is wrong/evil by its very nature. And it is the very nature of the act which does not require any specific detailing or definition in the law to consider murder a crime.
Some jurisdictions still take a common law view of murder. In such jurisdictions, precedent case law or previous decisions of the courts of law defines what is considered murder. However, although the common law is by nature flexible and adaptable, in the interests both of certainty and of securing convictions, most common law jurisdictions have codified their criminal law and now have statutory definitions of murder.
- 1986 Seville Statement on Violence (from UNESCO)
- "This Could Never Happen to Me - A Handbook for Families of Murder Victims and People Who Assist Them" - Hosted by the Texas Department of Criminal Justice
- Introduction and Updated Information on the Seville Statement on Violence
- U.S. Centers for Disease Control "Atlas of United States Mortality"
- Cezanne's depiction of "The Murder"
- Lord Mustill on the Common Law concerning murder
- Sir Edward Coke Co. Inst., Pt. III, ch.7, p. 50
- Tran, Mark (2011-03-28). "China and US among top punishers but death penalty in decline". The Guardian (London).
- "Avalon Project - Blackstone's Commentaries on the Laws of England - Book the Fourth - Chapter the Fourteenth : Of Homicide".
- Joshua Dressler (2001). Understanding Criminal Law (3rd ed.). Lexis.
- Dennis J. Baker (2012). "Chapter 11". Glanville Williams Textbook of Criminal Law. London.
- R v Tait  1 QB 290.
- Murder in the First and Second Degree (14-17) A murder which shall be perpetrated by ... poison, lying in wait, imprisonment, starving, torture, or by any other kind of willful, deliberate and premeditated killing or which shall be committed in the perpetration or attempted perpetration of any arson, rape or sex offense, robbery, kidnapping, burglary, or other felony committed or attempted with the use of a deadly weapon, shall be ... murder in the first degree ... and shall be punished by death or life imprisonment ... except that any person ... under 17 years of age at the time of the murder shall be punished with imprisonment ... for life. All other kinds of murder, including that which shall be proximately caused by the unlawful distribution of opium or any synthetic or natural salt, compound, derivative, or the preparation of opium ... cause the death of the user, shall be ... murder in the second degree and ... shall be punished as a Class C felony
- "Blackstone, Book 4, Chapter 14". Yale.edu. Retrieved 2010-06-25.
- A Dictionary of Modern Legal Usage By Bryan A. Garner, p. 545.
- "capital punishment". 2009. Retrieved 2014-09-14.
- Imperial Justice: Africans in Empire's Court - Page 107, Bonny Ibhawoh - 2013
- The French Parliament. "Article 122-5". French Criminal Law (in Français). Legifrance. Retrieved 2007-11-01.
- Margaret Otlowski, ''Voluntary Euthanasia and the Common Law'', Oxford University Press, 1997, pp. 175-177. Books.google.pl. 1997.
- "Man Kills Suspected Intruders While Protecting Neighbor's Property". ABC News. Retrieved 23 October 2014.
- "Texas man acquitted of killing Craigslist escort". Yahoo News. 7 June 2013. Retrieved 23 October 2014.
- "Killing in Self-defence". Retrieved 23 October 2014.
- People v. Davis, 7 Cal. 4th 797, 30 Cal. Rptr. 2d 50, 872 P.2d 591 (1994).
- M'Naughten's case,  All ER Rep 229.
- N.Y. Penal Law, § 40.15, found at N.Y. Assembly web site, retrieved April 10, 2014.
- "Code de la Santé Publique Chapitre III: Hospitalisation d'office Article L3213-1" (in Français). Legifrance. 2002. Retrieved 2007-10-23., note: this text refers to the procedure of involuntary commitment by the demand of the public authority, but the prefect systematically use that procedure whenever a man is discharged due to his dementia.
- The French Parliament. "Article 222-8". French Criminal Law. Legifrance. Retrieved 2007-11-01.
- The French Parliament. "Section II - Involuntary Offences Against Life". French Criminal Law. Legifrance. Retrieved 2007-11-01.
- (the so-called "Twinkie defense").
- Murder (English law)
- Murder (United States law)
- Murder (Romanian law)
- Murder (Brazilian law)
- "Parole Board of Ireland". Retrieved 23 October 2014.
- Yigal Amir
- See State v. Picotte, 2003 WI 42, 261 Wis. 2d 249 (2003)(search for "year-and-a-day rule")
- , 646 N.E.2d 582 (Ill. 1995)People v. Carrillo
- , 836 P.2d 102 (N.M. 1992)State v. Gabehart
- Rogers v. Tennessee, 532 U.S. 451 (2001).
- CBS News coverage of Barnes' acquittal Accessed May 24, 2010
- Georg Oesterdiekhoff. The steps of man towards civilization. BoD – Books on Demand. pp.169-170. ISBN 3-8423-4288-8
- 'Vulgate'' Deuteronomy Ch27 V24"'". Latinvulgate.com. Retrieved 2010-06-25.
- 'Parallel Hebrew Old Testament'' Deuteronomy Ch27 V24"'". Hebrewoldtestament.com. Retrieved 2010-06-25.
"Exodus 20v13". Young's Literal Translation. Retrieved 21 January 2011.
Thou dost not murder.
"Exodus 20v13". World English Bible. Retrieved 21 January 2011.
You shall not murder.
- American Speech - McCarthy, Kevin M.. Volume 48, pp. 77–83
- Secret Societies Handbook, Michael Bradley, Altair Cassell Illustrated, 2005. ISBN 978-1-84403-416-1
- Sinister sects: Thug, Mike Dash's investigation into the gangs who preyed on travellers in 19th-century India by Kevin Rushby, The Guardian, Saturday, June 11, 2005.
- "Thuggee (Thagi) (13th C. to ca. 1838)". Users.erols.com. Retrieved 2013-04-23.
- Rubinstein, W. D. (2004). Genocide: a history. Pearson Education. p. 82.
- "Science and Anthropology". Cdis.missouri.edu. Retrieved 2010-06-25.
- Hassig, Ross (2003). "El sacrificio y las guerras floridas". Arqueología mexicana, pp. 46–51.
- The Enigma of Aztec Sacrifice. Natural History, April 1977 Vol. 86, No. 4, pp. 46–51.
- Geoffrey Chaucer, Neilson and Patch, Eds. (1921) Selections from Chaucer, Harcourt, Brace, p. 469.
- Albrecht, H. & Sheehy, F. (2013) Woran wir sterben. Zeit-Grafik, 7. Feb. 2013, based on The Global Burden of Disease Study 2010, The Lancet, Vol. 380, Nr. 9859
- "WHO: 1.6 million die in violence annually". Online.sfsu.edu. 2002-10-04. Retrieved 2010-06-25.
- Rubin, Joel (2010-12-26). "Killing in L.A. drops to 1967 levels". latimes.com. Retrieved 2011-01-27.
- "FBI web site". Fbi.gov. 2001-09-11. Retrieved 2010-06-25.
- "Óbitos por Causas Externas 1996 a 2010" (in Portuguese). DATASUS. Retrieved 2012-06-05.
- Kingstone, Steve (2005-06-27). "UN highlights Brazil gun crisis". BBC News. Retrieved 2010-04-30.
- "Crime in India 2010" (PDF). National Crime Records Bureau. p. 24. Retrieved 2012-06-05.
- "Information on the death of the population of causes of death in the Russian Federation". Rosstat. Retrieved 2011-04-03.
- "Homicidio 2010" (PDF) (in Spanish). Instituto Nacional de Medicina Legal. p. 20. Retrieved 2011-09-11.
- "Murder in RSA for April to March 2003/2004 to 2010/2011" (PDF). South African Police Service. Retrieved 2012-06-05.
- "Crime in the United States by Volume and Rate per 100,000 Inhabitants, 1991–2010". Federal Bureau of Investigation. Retrieved 2012-06-05.
- "Estadísticas de Mortalidad" (in Spanish). Instituto Nacional de Estadística y Geografía. Retrieved 2011-09-14.
- "Derecho a la seguridad ciudadana" (PDF) (in Spanish). Programa Venezolano de Educación-Acción en Derechos Humanos. p. 397. Retrieved 2012-06-05.
- "Homicidios en Centroamérica" (PDF) (in Spanish). La Prensa Grafica de El Salvador. p. 1. Retrieved 2011-08-02.
- "Global Study on Homicide" (PDF). United Nations Office on Drugs and Crime. p. 95. Retrieved 2012-06-18.
- "Police-reported crime for selected offences, Canada, 2009 and 2010". Statistics Canada. Retrieved 2012-06-10.
- "State of Human Rights in 2010" (PDF). Human Rights Commission of Pakistan. p. 98. Retrieved 2012-06-11.
- "BRAZIL: Youth Still in Trouble, Despite Plethora of Social Programmes". IPS. March 30, 2007.
- "Twentieth Century Atlas - Homicide". Users.erols.com. Retrieved 2010-06-25.
- "Why Do Some Women Kill? - ABC News". Retrieved 23 October 2014.
- "Chapter 6". Retrieved 23 October 2014.
- "Homicide trends in the United States". Bureau of Justice Statistics.
- "Homicide Victims by Race and Sex". U.S. Census Bureau.
- "Encyclopedia of Victimology and Crime Prevention". Bonnie S. Fisher, Steven P. Lab (2010). p. 706. ISBN 1-4129-6047-9
- Ann L. Pastore; Kathleen Maguire (eds.). Sourcebook of criminal justice statistics Online (31st ed.). Albany, New York:
- "Race and crime: a biosocial analysis". Anthony Walsh (2004). Nova Publishers. p. 23. ISBN 1-59033-970-3
- "MPS Response to Guns, Gangs and Knives in London".
- Harris, Anthony R.; Stephen H. Thomas; Gene A. Fisher; David J. Hirsch (May 2002). "Murder and medicine: the lethality of criminal assault 1960-1999" (fee required). Homicide studies 6 (2): 128–166.
- Christopher Effgen (2001-09-11). "Disaster Center web site". Disastercenter.com. Retrieved 2010-06-25.
- Why Fewer Murder Cases Get Solved These Days by Lewis Beale. 19 May 2009.
- CS Monitor by Brian Whitley. Christian Science Monitor. 24 December 2008.
- Spierenburg, Pieter, A History of Murder: Personal Violence in Europe from the Middle Ages to the Present, Polity, 2008. Referred to in "Rap Sheet Why is American history so murderous?" by Jill Lepore New Yorker, November 9, 2009
- "Homicide Rates in the United States 1900-1990".
- "Murder and Medicine: The Lethality of Criminal Assault 1960-1999".
- Randolph Roth (October 2009). "American Homicide Supplemental Volume (AHSV), European Homicides (EH)".
- "Freakonomics", Steven D. Levitt, Stephen J. Dubner, 2005, ISBN 0-06-073132-X
- Morris, Thomas D. (1999). Southern Slavery and the Law, 1619-1860. University of North Carolina Press. p. 172.
- Fede, Andrew (2012). "People Without Rights (Routledge Revivals): An Interpretation of the Fundamentals of the Law of Slavery in the U.S. South".
- John Andrew, The Hanging of Arthur Hodge, Xlibris, 2000, ISBN 0-7388-1930-1.
- "Wanderings in Corsica: Its History and Its Heroes". Ferdinand Gregorovius (1855). p.196.
- Topics related to murder
Certain countries employ the concept of first-, second-, and third-degree murder. Canadian law distinguishes first- and second-degree murder. Both the United States and Peru have respective degrees of first-, second-, and third-degree murder. See Degrees of murder in the United States and Murder (Peruvian law).
Degrees of murder by country
Specific murder law
Southern slave codes did make willful killing of a slave illegal in most cases. For example, the 1860 Mississippi case of Oliver v. State charged the defendant with murdering his own slave. In 1811, the wealthy white planter, Arthur Hodge, was executed for murdering several of his slaves on his plantation in the British West Indies.
The specific factors driving this dynamics in murder rates are complex and not universally agreed upon. Much of the raise in the U.S. murder rate during the first half of the 20th century is generally thought to be attributed to gang violence associated with the Prohibition. Since most murders are committed by young males, the near simultaneous low in the murder rates of major developed countries circa 1960 can be attributed to low birth rates during the Great Depression and World War II. Causes of further moves are more controversial. Some of the more exotic factors claimed to affect murder rates include the availability of abortion and the likelihood of chronic exposure to lead during childhood (due to the use of leaded paint in houses and tetraethyllead as a gasoline additive in internal combustion engines).
A similar, but less pronounced pattern has been seen in major European countries as well. The murder rate in the United Kingdom fell to 1 per 100,000 by the beginning of the 20th century and as low as 0.62 per 100,000 in 1960, and was at 1.28 per 100,000 as of 2009. The murder rate in France (excluding Corsica) bottomed out after World War II at less than 0.4 per 100,000, quadrupling to 1.6 per 100,000 since then.
In the United States, murder rates have been higher and have fluctuated. They fell below 2 per 100,000 by 1900, rose during the first half of the century, dropped in the years following World War II, and bottomed out at 4.0 in 1957 before rising again. The rate stayed in 9 to 10 range most of the period from 1972 to 1994, before falling to 5 in present times. The increase since 1957 would have been even greater if not for the significant improvements in medical techniques and emergency response times, which mean that more and more attempted homicide victims survive. According to one estimate, if the lethality levels of criminal assaults of 1964 still applied in 1993, the country would have seen the murder rate of around 26 per 100,000, almost triple the actually observed rate of 9.5 per 100,000.
According to scholar Pieter Spierenburg homicide rates per 100,000 in Europe have fallen over the centuries, from 35 per 100,000 in medieval times, to 20 in 1500 AD, 5 in 1700, to below two per 100,000 in 1900.
Despite the immense improvements in forensics in the past few decades, the fraction of murders solved has decreased in the United States, from 90% in 1960 to 61% in 2007. Solved murder rates in major U.S. cities varied in 2007 from 36% in Boston, Massachusetts to 76% in San Jose, California. Major factors affecting the arrest rate include witness cooperation and the number of people assigned to investigate the case.
Development of murder rates over time in different countries is often used by both supporters and opponents of capital punishment and gun control. Using properly filtered data, it is possible to make the case for or against either of these issues. For example, one could look at murder rates in the United States from 1950 to 2000, and notice that those rates went up sharply shortly after a moratorium on death sentences was effectively imposed in the late 1960s. This fact has been used to argue that capital punishment serves as a deterrent and, as such, it is morally justified. Capital punishment opponents frequently counter that the United States has much higher murder rates than Canada and most European Union countries, although all those countries have abolished the death penalty. Overall, the global pattern is too complex, and on average, the influence of both these factors may not be significant and could be more social, economic, and cultural.
Workplace homicide is the fastest growing category of murder in America.
In the US, murder is the leading cause of death for African American males aged 15 to 34. Between 1976 and 2008, African Americans were victims of 329,825 homicides. In 2006, Federal Bureau of Investigation's Supplementary Homicide Report indicated that nearly half of the 14,990 murder victims were Black (7421). In the year 2007 non-negligent homicides, there were 3,221 black victims and 3,587 white victims. While 2,905 of the black victims were killed by a black offender, 2,918 of the white victims were killed by white offenders. There were 566 white victims of black offenders and 245 black victims of white offenders. The "white" category in the Uniform Crime Reports (UCR) includes non-black Hispanics. In London in 2006, 75% of the victims of gun crime and 79% of the suspects were "from the African/Caribbean community." Murder demographics are affected by the improvement of trauma care, which has resulted in reduced lethality of violent assaults – thus the murder rate may not necessarily indicate the overall level of social violence.
In the United States, 666,160 people were killed between 1960 and 1996. Approximately 90% of murders in the US are committed by males. Between 1976 and 2005, 23.5% of all murder victims and 64.8% of victims murdered by intimate partners were female. For women in the US, homicide is the leading cause of death in the workplace.
The following absolute murder counts per-country are not comparable because they are not adjusted by each country's total population. Nonetheless, they are included here for reference, with 2010 used as the base year (they may or may not include justifiable homicide, depending on the jurisdiction). There were 52,260 murders in Brazil, consecutively elevating the record set in 2009. Over half a million people were shot to death in Brazil between 1979 and 2003. 33,335 murder cases were registered across India, about 19,000 murders committed in Russia, approximately 17,000 murders in Colombia (the murder rate was 38 per 100,000 people, in 2008 murders went down to 15,000), approximately 16,000 murders in South Africa, approximately 15,000 murders in the United States, approximately 26,000 murders in Mexico, approximately 13,000 murders in Venezuela, approximately 4,000 murders in El Salvador, approximately 1,400 murders in Jamaica, approximately 550 murders in Canada and approximately 470 murders in Trinidad and Tobago. Pakistan reported 12,580 murders.
Murder rates by country. Murder rates in jurisdictions such as Japan, Singapore, Hong Kong, Iceland, Norway, Switzerland and Austria are among the lowest in the world, around 0.5 cases per 100,000 people per year; the rate of the United States is among the highest of developed countries, around 5.5 in 2004, with rates in larger cities sometimes over 40 per 100,000. The top ten highest murder rates are in Honduras (91.6 per 100,000), El Salvador, Ivory Coast, Venezuela, Belize, Jamaica, U.S. Virgin Islands, Guatemala, Saint Kitts and Nevis and Zambia. (UNODC, 2011 - full table here).
Murder rates vary greatly among countries and societies around the world. In the Western world, murder rates in most countries have declined significantly during the 20th century and are now between 1 and 4 cases per 100,000 people per year.
An estimated 520,000 people were murdered in 2000 around the globe. Another study estimated the world-wide murder rate at 456,300 in 2010 with a 35% increase since 1990. Two-fifths of them were young people between the ages of 10 and 29 who were killed by other young people. Because murder is the least likely crime to go unreported, statistics of murder are seen as a bellwether of overall crime rates.
The term 'Assassin' derives from Hashshashin, a militant Ismaili Shi`ite sect, active from the 8th to 14th centuries. This mystic secret society killed members of the Abbasid, Fatimid, Seljuq and Crusader elite for political and religious reasons. The Thuggee cult that plagued India was devoted to Kali, the goddess of death and destruction. According to some estimates the Thuggees murdered 1 million people between 1740 and 1840. The Aztecs believed that without regular offerings of blood the sun god Huitzilopochtli would withdraw his support for them and destroy the world as they knew it. According to Ross Hassig, author of Aztec Warfare, "between 10,000 and 80,400 persons" were sacrificed in the 1487 re-consecration of the Great Pyramid of Tenochtitlan.
In Islam according to the Qur'an, one of the greatest sins is to kill a human being who has committed no fault. "For that cause We decreed for the Children of Israel that whosoever killeth a human being for other than manslaughter or corruption in the earth, it shall be as if he had killed all mankind, and whoso saveth the life of one, it shall be as if he had saved the life of all mankind."[Quran 5:32] "And those who cry not unto any other god along with Allah, nor take the life which Allah hath forbidden save in (course of) justice, nor commit adultery - and whoso doeth this shall pay the penalty."[Quran 25:68]
In Judeo-Christian traditions, the prohibition against murder is one of the Ten Commandments given by God to Moses in (Exodus: 20v13) and (Deuteronomy 5v17). The Vulgate and subsequent early English translations of the Bible used the term secretly killeth his neighbour or smiteth his neighbour secretly rather than murder for the Latin clam percusserit proximum. Later editions such as Young's Literal Translation and the World English Bible have translated the Latin occides simply as murder rather than the alternatives of kill, assassinate, fall upon, or slay.
One of the oldest known prohibitions against murder appears in the Sumerian Code of Ur-Nammu written sometime between 2100 and 2050 BC. The code states, "If a man commits a murder, that man must be killed." The payment of weregild was an important legal mechanism in early Germanic society. If someone was killed, the guilty person would have to pay weregild to the victim's family. The other common form of legal reparation at this time was blood revenge.
Evans-Pritchard says about the Nuer from Sudan: "Homicide is not forbidden, and Nuer do not think it wrong to kill a man in fair fight. On the contrary, a man who slays another in combat is admired for his courage and skill." (Evans-Pritchard 1956: 195) This statement is true for most African tribes, for pre-modern Europeans, for Indigenous Australians, and for Native Americans, according to ethnographic reports from all over the world. ... Homicides rise to incredible numbers among headhunter cultures such as the Papua. When a boy is born, the father has to kill a man. He needs a name for his child and can receive it only by a man, he himself has murdered. When a man wants to marry, he must kill a man. When a man dies, his family again has to kill a man.
In the past, certain types of homicide were lawful and justified. Georg Oesterdiekhoff wrote that:
Origins and history
In Philadelphia, a 74-year-old man, William Barnes, was acquitted of murder charges on May 24, 2010. He was on trial for murder for the death of Philadelphia police officer Walter Barkley. Barnes shot Barkley on November 27, 1966, and served 16 years in prison for attempted murder. Barkley died on August 19, 2007, allegedly from complications of the wounds suffered nearly 41 years earlier.
In the United States, many jurisdictions have abolished the rule as well. Abolition of the rule has been accomplished by enactment of statutory criminal codes, which had the effect of displacing the common-law definitions of crimes and corresponding defenses. In 2001, the Supreme Court of the United States held that retroactive application of a state supreme court decision abolishing the year-and-a-day rule did not violate the Ex Post Facto Clause of Article I of the United States Constitution.
In England and Wales, the "year-and-a-day rule" was abolished by the Law Reform (Year and a Day Rule) Act 1996. However, if death occurs three years or more after the original attack then prosecution can take place only with the Attorney-General's approval.
With advances in modern medicine, most countries have abandoned a fixed time period and test causation on the facts of the case.
In some common law jurisdictions, a defendant accused of murder is not guilty if the victim survives for longer than one year and one day after the attack. This reflects the likelihood that if the victim dies, other factors will have contributed to the cause of death, breaking the chain of causation. Subject to any statute of limitations, the accused could still be charged with an offence reflecting the seriousness of the initial assault.
In the United States and Canada, these murders are referred to as first-degree or aggravated murders. Murder, under English criminal law, always carries a mandatory life sentence, but is not classified into degrees. Penalties for murder committed under aggravating circumstances are often higher, under English law, than the 15-year minimum non-parole period that otherwise serves as a starting point for a murder committed by an adult.
- Murder of a police officer, judge, fireman or witness to a crime
- Murder of a pregnant woman
- Crime committed for pay or other reward
- Exceptional brutality or cruelty
- Murder for a political cause,
Murder with specified aggravating circumstances is often punished more harshly. Depending on the jurisdiction, such circumstances may include:
In those jurisdictions using the Uniform Penal Code, such as Harvey Milk.
For a killing to be considered murder, there normally needs to be an element of intent. A defendant may argue that he or she took precautions not to kill, that the death could not have been anticipated, or was unavoidable. As a general rule, manslaughter constitutes reckless killing, but manslaughter also includes criminally negligent (i.e. grossly negligent) homicide.
Some countries, such as Brazil, Canada, Mexico, Italy, Norway, Sweden, the United Kingdom, New Zealand, and Australia, allow postpartum depression (also known as post-natal depression) as a defense against murder of a child by a mother, provided that a child is less than two years old (this may be the specific offense of infanticide rather than murder and include the effects of lactation and other aspects of post-natal care).
Those who successfully argue a defense based on a mental disorder are usually referred to mandatory clinical treatment until they are certified safe to be released back into the community, rather than prison.
- A person is not criminally liable who, when the act was committed, was suffering from a psychological or neuropsychological disorder which destroyed his discernment or his ability to control his actions.
- A person who, at the time he acted, was suffering from a psychological or neuropsychological disorder which reduced his discernment or impeded his ability to control his actions, remains punishable; however, the court shall take this into account when it decides the penalty and determines its regime.
Under the French Penal Code:
§ 40.15 Mental disease or defect. In any prosecution for an offense, it is an affirmative defense that when the defendant engaged in the proscribed conduct, he lacked criminal responsibility by reason of mental disease or defect. Such lack of criminal responsibility means that at the time of such conduct, as a result of mental disease or defect, he lacked substantial capacity to know or appreciate either: 1. The nature and consequences of such conduct; or 2. That such conduct was wrong.—N.Y. Penal Law, § 40.15
Under New York law, for example:
- That the defendant had a serious mental illness, disease, or defect.
- That the defendant's mental condition, at the time of the killing, rendered the perpetrator unable to determine right from wrong, or that what he or she was doing was wrong.
Mental disorder may apply to a wide range of disorders including psychosis caused by schizophrenia and dementia, and excuse the person from the need to undergo the stress of a trial as to liability. Usually, sociopathy and other personality disorders are not legally considered insanity, because of the belief they are the result of free will in many societies. In some jurisdictions, following the pre-trial hearing to determine the extent of the disorder, the defense of "not guilty by reason of insanity" may be used to get a not guilty verdict. This defense has two elements:
Some countries allow conditions that "affect the balance of the mind" to be regarded as mitigating circumstances. This means that a person may be found guilty of "manslaughter" on the basis of "diminished responsibility" rather than murder, if it can be proved that the killer was suffering from a condition that affected their judgment at the time. Depression, post-traumatic stress disorder and medication side-effects are examples of conditions that may be taken into account when assessing responsibility.
California's murder statute, Penal Code Section 187, was interpreted by the Supreme Court of California in 1994 as not requiring any proof of the viability of the fetus as a prerequisite to a murder conviction. This holding has two implications. The first is a defendant in California can be convicted of murder for killing a fetus which the mother herself could have terminated without committing a crime. The second, as stated by Justice Stanley Mosk in his dissent, because women carrying nonviable fetuses may not be visibly pregnant, it may be possible for a defendant to be convicted of intentionally murdering a person he did not know existed.
All jurisdictions require that the victim be a natural person; that is a organism such as a plant or bacterium.
- Capital punishment: some countries practice the death penalty. Capital punishment ordered by a legitimate court of law as the result of a conviction in a criminal trial with due process for a serious crime. The 47 Member States of the Council of Europe are prohibited from using the death penalty.
- Euthanasia, doctor assisted suicide: the administration of lethal drugs by a doctor to a terminally ill patient, if the intention is solely to alleviate pain, is seen in many jurisdictions as a special case (see the doctrine of double effect and the case of Dr John Bodkin Adams).
- A killing simply to prevent the theft of one's property may or may not be legal, depending on the jurisdiction. In the US, such a killing is legal in Texas. In recent years, Texas has been the scene of some very controversial incidents that involved killing to protect property, that have led to discussions of the laws and social norms of the state (see Joe Horn shooting controversy). In a highly controversial case, in 2013, a jury in south Texas acquitted a man who killed a prostitute, who, after receiving $150 from the man in exchange for sex, refused to have sex with the man, and attempted to run away with his money. The man's lawyer argued that the man was trying to retrieve property which was stolen during night time, an action which allows for the use of deadly force in Texas. The jury accepted this defense. There was major controversy in this case, due to the fact that there were questions about whether the money was in fact stolen, since the man had given it voluntarily to the prostitute, and the "contract" of prostitution is in fact an illegal contract in Texas, since both buying and selling sex are criminal offenses.
- Killing an intruder who is found by an owner to be in the owner's home (having entered unlawfully): legal in most US states (see Castle doctrine).
- Killing to prevent specific forms of aggravated rape or sexual assault - killing of attacker by the potential victim or by witnesses to the scene; this is especially the case in regard to child rape- legal in parts of the US and in various countries
- In some parts of the world, especially in jurisdictions which apply Sharia law, the killing of a woman or girl in specific circumstances (e.g., when she commits adultery) and is killed by husband or other family members, known as honor killing, is not considered murder.
Specific to certain countries
- Self-defense: acting in self-defense or in defense of another person is generally accepted as legal justification for killing a person in situations that would otherwise have been murder. However, a self-defense killing might be considered manslaughter if the killer established control of the situation before the killing took place. In the case of self-defense it is called a "justifiable homicide".
- Unlawful killings without malice or intent are considered manslaughter.
- In many common law countries, provocation is a partial defense to a charge of murder which acts by converting what would otherwise have been murder into manslaughter (this is voluntary manslaughter, which is more severe than involuntary manslaughter)
- Accidental killings are considered homicides. Depending on the circumstances, these may or may not be considered criminal offenses; they are often considered manslaughter.
- Suicide does not constitute murder in most societies. Assisting a suicide, however, may be considered murder in some circumstances.
- Killing of enemy combatants by lawful combatants in accordance with lawful orders in war, although illicit killings within a war may constitute murder or homicidal war crimes. (see the Laws of war article)
Although laws vary by country, there are circumstances of exclusion that are common in many legal systems.
 During the colonial era, some sharia courts would blend sharia law with common law and at other times the two would be at odds with one another especially during the allocation of blood money.