In criminal law, murder is the crime of causing the death of another human being, without lawful excuse, and with intent to kill or with an intent to cause grievous bodily harm, which is traditionally termed "malice aforethought". In attempted murder, the mens rea requirement, Latin for "guilty mind", is limited. In some common law jurisdictions, an accused is not guilty of murder if the victim lives for longer than a year and a day after the attack. This reflects the likelihood that, if the victim has survived so long after the initial attack, there will be other factors contributing to the cause of death and so break the chain of causation. Subject to the local statute of limitation, the accused can still be charged with an offense representing the seriousnessof the initial assault. But, with the advance of modern medicine, the majority of countries have abandoned a fixed time period and test causation on the facts. In most countries murder is considered the most serious crime, and invokes the highest punishment] available under the law. As with most legal terms, the precise definition varies between jurisdictions.
Most 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.
The defenses of insanity or mental disorder may apply to a wide range of disorders including psychosis caused by schizophrenia, and excuse the person from the need to undergo the stress of a trial as to liability. In some jurisdictions, following the pre-trial hearing to determine the extent of the disorder, the verdict "not guilty by reason of insanity" may be used. Some countries, such as Canada, Italy, the United Kingdom and Australia, allow post-partum depression, or 'baby-blues', as a defense against murder of a child by a mother, provided that a child is less than a year 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.
Country-specific murder law
Recent statistics show that there were 859 homicides in England and Wales in one year (April 2004- March 2005, ). This is low compared to the United States with 16,137 murders in 2004 , however these are numbers which do not take different population sizes into account: a better perspective can be gained by comparing murders per year to population (1.6 murders for every hundred thousand people in England and Wales, 5.5 in the USA, and 63 in Colombia - source). Because the newspaper coverage tends to focus on the more lurid or controversial cases (e.g. Tony Martin), there is considerable public misunderstanding as to the actual law. The Law Commission Final Report on Partial Defences to Murder (2004)  commissioned research to determine the extent of this misunderstanding and reported at 2.35:
Although the sample was small, the research showed that the public accepts a range of culpability within the definition of murder and so rejects the idea of a single mandatory life sentence. For those interested, the Report also lists all the main European and common law definitions for homicide at 2.53/2.54.
In English law, the definition of murder is:
Contrast this with the original definition by Sir Edward Coke in 1797 of:
Note that it is no longer necessary for the victim to die within a year and a day of the offence.
Specific statutory instances of situations where death is caused are:
The aggravated form of criminal damage, including arson, under s1(2) Criminal Damage Act 1971 could be the anticipatory offence rather than a charge of attempted murder.
Any other killing would be considered either manslaughter in English law or an accident.
English Law also allows for transferred malice. For example, where a man fires a gun with the intent to kill person A but the shot misses and kills an otherwise unconnected person B, the intent to kill transfers from person A to person B and a charge of murder would stand. The accused could also be charged with the attempted murder of A.
As to mens rea, the model direction to be given to juries for Intention in English law following R v. Woollin , is a modified version of that proposed by Lord Lane, C.J. in R v Nedrick  1 WLR 1025, namely:
The defences of duress and necessity in English law are excluded from murder cases. An exception is Re A , a case involving a pair of conjoined twins. However, the judge noted the old legal adage that 'hard cases make bad law' and recommended that the precedent should not be followed.
Comparatively recent adaptations to the English law of murder include the abolition of the "year and a day rule", and the proposed introduction of a less restrictive regime for corporate manslaughter. The Law Commission Consultation Paper No. 177 also advocates a redefinition of murder and a limitation of the scope of manslaughter 
In 2004 the homicide rate in Canada was 2.0 per 100 000 people or approximately 650 homicides per year . This is equivalent to numbers in most of the western world, except the U.S. which has triple the number per capita. The main methods of murder in Canada are shootings (30%), stabbings (30%), and beatings (22%).
Canada has four types of crime that can be considered murder:
(there are exceptions to the above - certain types of murder are always first degree murder, such as the killing of a police officer, and certain types of killings are murder regardless of intent, such as a death resulting from sexual assault)
The maximum penalties for murder are:
For every murder in Canada there are about 1.5 attempted murders. Attempted murder carries the same consequences as murder itself; it is the intent, not the result, that determines the sentence.
About one in three Canadian murders are committed by a family member. One in eight is gang related. About 80% of murderers in Canada are caught within a year.
(All statistics are from the 2003 census)incorrect
The United States
In the United States, the principle of dual sovereignty applies to homicide, as to other crimes. If murder is committed within the borders of a state, that state has jurisdiction. If the victim is a federal official, an ambassador, consul or other foreign official under the protection of the United States, or if the crime took place on federal property or involved crossing state borders, or in a manner that substantially affects interstate commerce or national security, then the Federal Government also has jurisdiction. If a crime is not committed within any state, then Federal jurisdiction is exclusive: examples include the District of Columbia, naval or US-flagged merchant vessels in international waters, or a military base abroad. In cases where a murder involves both state and federal jurisdiction, the offender can be tried and punished separately for each crime without raising issues of double jeopardy.
Modern codifications tend to create a genus of offenses, known collectively as homicide, of which murder is the most serious species, followed by manslaughter which is less serious, and ending finally in justifiable homicide, which is not a crime at all. Because there are 51 jurisdictions, each with its own criminal code, this section treats only the crime of murder, and does not deal with state-by-state specifics.
At base, murder consists of an intentional unlawful act with a design to kill and fatal consequences. Generally, an intention to cause great bodily harm is considered indistinguishable from an intention to kill, as is an act so inherently dangerous that any reasonable person would realize the likelihood of fatality. Thus, if the defendant hurled the victim from a bridge, it is no defense to argue that harm was not contemplated, or that the defendant hoped only to break bones.
The intent to commit murder is often called malice aforethought, and can be inferred when the defendant commits an act that shows depraved indifference to human life, or (in federal court and those states that apply the felony murder rule) whenever a victim is killed during the commission of another felony, whether or not the defendant intended the killing, or even committed the fatal act. In this case, the intention to place the victim in great bodily harm is inferred from the defendant's intent to commit the felony. Some states also require the underlying felony to be an 'inherently' dangerous one.
Degrees of murder
Before the famous case of Furman v. Georgia, most states distinguished two degrees of murder. While the rules differed by state, a reasonably common scheme was that of Pennsylvania, passed in 1794: "Murder which shall be perpetrated by means of poison, or by lying in wait, or by any other kind of wilful, deliberate, and premeditated killing, or which shall be committed in the perpetration or attempt to perpetrate, any arson, rape, robbery, or burglary, shall be deemed murder of the first degree; and all other kinds of murder shall be deemed murder of the second degree." "Murder one", as the term was popularized by novels and television, carried a penalty of death, or life in prison, while the penalty for "murder two" was generally around 20 years in prison.
After the Supreme Court placed new requirements on the imposition of the death penalty, most states adopted one of two schemes. In both, third degree murder became the catch-all, while first degree murder was split. The difference was whether some or all first degree murders should be eligible for the most serious penalty (generally death, but sometimes life in prison without the possibility of parole.).
Some states, such as California, simply preserved the old distinction and have no offense called third degree murder. Other states use the term "capital murder" for those offenses that merit death, and the term is often used even in states whose statutes do not include the term. As of 2006, 38 states and the federal government have laws allowing capital punishment for certain murders and related crimes (such as treason and terrorism). The penalty is rarely asked for and more rarely imposed, but it has generated tremendous public debate. See also capital punishment.
Murder of a fetus
Under the common law, if an assault on a pregnant woman resulted in a stillbirth, it was not considered murder, because the child had not drawn breath outside the womb. Remedies were limited to criminal penalties for the assault on the woman, and a tort action for loss of the economic services of the child and/or emotional pain and suffering. With the widespread adoption of laws against abortion, the assailant could of course be charged with that offense, but the penalty was often only a fine and a few days in jail.
When the Supreme Court greatly restricted laws prohibiting abortions in its famous Roe v. Wade decision (1972) even those sanctions became harder to use. A popular perception grew up that Roe had changed the law of murder. After several well-publicized cases, Congress passed the Unborn Victims of Violence Act, which specifically criminalizes harming a fetus, with the same penalties as for a human being. Several states have or are considering similar legislation.
In Germany the term Mord (murder) is officially used for the premeditated killing of another person:
A killing which is not a murder may be either Totschlag (manslaughter) or fahrlässige Tötung (negligent homicide). Also, if the death is not a foreseeable consequence of an intended or not intended act of violence, it might be classified as Körperverletzung mit Todesfolge (injury resulting in death). The penalty for Mord is lifelong imprisonment, which is usually suspended after 15 years on a probation of 5 years or, if the court decided on a special gravity (Feststellung der besonderen Schwere der Schuld) it won't be suspended and the convict has the right to first ask for a pardon after 18 years in prison. The penalty for Totschlag is five to fifteen years in prison.
In Switzerland murder (Mord) is also used for the premeditated killing of another person, but only if the motives are cruel, disgusting or show an overall disrespect of human life. Penalty ranges from several years to life in prison. Furthermore, homicide is considered murder if it is cruel and/or unusual, done so using explosives or arson, or if it is done to satisfy perverse lusts. Any homicide not meeting these standards is considered to be a killing (Tötung), and the penalty is not as heavy. Most homicides in Switzerland are considered killings, with the penalty ranging from 5 to 20 years.
The Swiss equivalent for manslaughter is Totschlag. Killers are sentenced for Totschlag when they committed the crime in a very, and especially excusable, state of excitement (a "Crime of passion"). For example, a wife who's been mistreated by her husband for years, and kills him in a fit of rage, would be sentenced for Totschlag. The penalty is one to five years in prison.
There are many other privileged variants of killing, similar to manslaughter, such as killing on demand of the "victim" or assisted suicide, in which case the punishment is considerably lower.
By Dutch law, murder (moord) is punishable by a maximum sentence of life imprisonment, which is the longest prison sentence the law allows. A common misconception is that the maximum sentence is 30 years (20 until 2006): this is the longest sentence that can be imposed other than life imprisonment. However, a life sentence is only imposed under special circumstances, such as multiple murders or prior convictions. The average sentence is 12 to 13 years. In addition to a prison sentence, the judge may sentence the suspect to TBS, or 'terbeschikkingstelling', meaning detention in a psychiatric institution, sometimes including forced treatment. TBS is imposed for a number of years (most often in relation to the severity of the crime) and thereafter prolonged if deemed necessary by a committee of psychiatrists. This can be done indefinitely, and has therefore been criticized as being a life sentence in disguise. Voluntary Manslaughter (doodslag) is punishable by a prison sentence of up to 15 years, or life imprisonment when committed during the commission of a crime or as an act of terrorism. Involuntary Manslaughter (dood door schuld) is punishable by a prison sentence of up to two years. If Involuntary Manslaughter is caused by recklessness, the maximum sentence that can be imposed is four years.
In 2003, 202 murders were committed in the Netherlands.
Finnish law calls the crime of causing the death of another human being "manslaughter" (tappo). The minimum sentence is eight years of imprisonment. Attempt is punishable. The crime of murder (murha) is defined as a manslaughter:
In jurisprudence, the comparison of an actual crime against "especially brutal or cruel way"-standard has been understood to mean comparison to "usual" homicide cases. In recent cases, the Finnish Supreme Court has not considered a single axe stroke on the head, or strangulation to be "especially brutal or cruel". On the other hand, causing death by jumping on a person's chest and head and firing over 10 times upon a person's torso have been considered to fulfill the standard.
The only sentence for murder is life in prison. Until 2006, this meant an actual life sentence which could be pardoned only by the president. However, the presidents have since 1960's regularly given pardon to practically all offenders after a time of 12-15 years. In 2006, the legislation was changed so that all life sentences are reviewed by an apellate court after they have been executed for 12 years. If the convict is still deemed a danger to society, his case will be reviewed every two years after this. Involuntary confinement to a psychiatric institution may also result, sometimes after the sentence is served. The involuntary treament ends when the psychiatrist decides so, or when a court decrees it no longer necessary in a periodical review.
There is also the crime of "death" (surma), which is a "manslaughter" under mitigating circumstances, with the punishment of four to ten years. Involuntary manslaughter (kuolemantuottamus) has a maximum punishment of two years of imprisonment or fine. Infanticide carries a punishment of at least four months and at most four years in prison.
Israel had 173 murders in 2004, compared to 147 murders in 2000 .
There are five types of homicide in Israel:
Vikings (8th to 11th centuries)
The Viking culture had a very different concept of murder. If a person killed someone, then it was up to the murderer to pay the family fair compensation (weregild) for the labor lost by the member's death. If the perpetrator refused to pay weregild, it was up to the family of the slain to extract it from the perpetrator, or take his life. In Nordic countries, the payment of weregild was used in homicide cases until the 16th century.
The only other type of killing with consequences in Viking culture was "unjust killing', i.e., while the victim was sleeping, or if the victim's back was turned. While there were no more financial repercussions for this other than the normal rules of weregild, the killer in question suffered from a tremendous loss of trust and might be declared outlaw.
Other usages involving the word
The word "murder" is sometimes used colloquially to mean some forms of mistreatment, e.g. a bad singer "murdering" a song, or describing something difficult to handle as "absolute murder". Sometimes sports announcers may make comments like "That team is getting murdered out there!" "The home team was murdered tonight." Murder is also used in the sense of desiring something greatly, eg. "I could murder a cup of tea". A murder is also the name given to a flock of crows.
In the U.S. 187 is a well-known slang term for murder, and it often appears in music. The number refers to section 187 of the California Penal Code which covers murder.
Murder occurrences vary wildly among different countries and societies. In the Western world, murder rates in most countries have declined significantly during 20th century and are now between 1-3 cases per 100,000 people per year. Murder rates of Japan and Iceland are among the lowest in the world, around 0.5; rate of United States is highest among all developed countries, at 5.5 (2004, ). On the other hand, developing countries often have rates of 10-100 murders per 100,000 people per year.
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 United States during 1950-2000  and notice that those rates went up sharply shortly after a moratorium on death sentences was effectively imposed in late 1960's. 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 United States have much higher murder rates than Canada and European Union countries, although all those countries have abolished the death penalty. Gun control advocates further point out that, unlike the United States, many European countries disallow gun ownership by private citizens. Overall, the global pattern is too complex and, on average, the influence of both these factors is probably insignificant.
It is also often claimed that murder rates are correlated with overall wealth of the population (i.e. that murders happen more often in societies where larger percentage of people lives below the poverty level ). This claim is not supported by evidence. On the other hand, many researchers have observed significant correlation between murder rates and wealth distribution inequality, as measured by Gini coefficient.
In the Western World, nearly 90% of all murders are committed by males; yet, according the US Department of Justice, males are also the victims of 74.6% of murders. There is a sharp peak in the age distribution of murderers between the ages of 17 and 30. People become increasingly unlikely to commit a murder as they age. Incidents of children and adolescents committing murders are also extremely rare.
Murder demographics are affected by increasing medical technology: victims that might once have died are now able to be saved, leading to a lower murder rate but not affecting the overall rate of violent assault. Thus the demographics of murder are not necessarily a good indicator of overall societal violence.