Many jurisdictions divide murder by degrees. The distinction between first- and second-degree murder exists, for example, in and .
The most common division is 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 depend on the jurisdiction, but may include a specific intent to kill, premeditation, or deliberation. In some, murder committed by acts such as , , or are also treated as first-degree murder. A few states in the U.S. further distinguish , but they differ significantly in which kinds of murders they classify as second-degree versus third-degree. For example, Minnesota defines third-degree murder as , whereas Florida defines third-degree murder as (except when the underlying felony is specifically listed in the definition of first-degree murder).
Some jurisdictions also distinguish premeditated murder. This is the of wrongfully and intentionally causing the death of another being (also known as murder) after rationally considering the timing or method of doing so, in order to either increase the likelihood of success, or to evade detection or apprehension. laws in the vary as to definitions of "premeditation". In some states, premeditation may be construed as taking place mere seconds before the murder. Premeditated murder is one of the most serious forms of , and is punished more severely than or other types of homicide, often with a without the possibility of , or in some countries, the . In the U.S, ( ) criminalizes premeditated murder, felony murder and second-degree murder committed under situations where federal jurisdiction applies. In Canada, the classifies as either 1st- or 2nd-degree. The former type of murder is often called premeditated murder, although premeditation is not the only way murder can be classified as first-degree.
Common law
According to Blackstone, English identified murder as a public wrong. According to common law, murder is considered to be , that is an act which is evil within itself. An act such as murder is wrong or 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 view of murder. In such jurisdictions, what is considered to be murder is defined by case law or previous decisions of the courts of law. 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 their criminal law and now have statutory definitions of murder.
ExclusionsGeneral
Although laws vary by country, there are circumstances of exclusion that are common in many legal systems.
Killing of enemy combatants who have not surrendered by lawful combatants, in accordance with lawful orders in war, is also generally not considered murder; although illicit killings within a war may constitute murder or homicidal . (see the article): 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 .In many common law countries, 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 . Depending on the circumstances, these may or may not be considered criminal offenses; they are often considered . does not constitute murder in most societies. Assisting a suicide, however, may be considered murder in some circumstances.Specific to certain countries: some countries practice the death penalty. Capital punishment may be ordered by a legitimate court of law as the result of a conviction in a with for a serious crime. The 47 Member States of the are prohibited from using the death penalty., doctor-assisted suicide: the administration of lethal drugs by a doctor to a patient, if the intention is solely to alleviate pain, in many jurisdictions it is seen as a special case (see the doctrine of and the case of ).Killing to prevent the theft of one's property may be legal, depending on the jurisdiction. In 2013, a jury in south Texas acquitted a man who killed a who attempted to run away with his money.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 ).Killing to prevent specific forms of aggravated rape or – killing of attacker by the potential victim or by witnesses to the scene; legal in parts of the US and in various other countries.In Pakistan, the killing of a woman or girl in specific circumstances (e.g., when she commits and is killed by her husband or other family members, known as ) is not considered murder.In the United States, in some states and in federal jurisdiction, a killing by a police officer is excluded from prosecution if the officer believes they are being threatened with deadly force by the victim. This may include such actions by the victim as reaching into a glove compartment or pocket for license and registration, if the officer thinks that the victim might be reaching for a gun. is similar to that of . Therefore, a murder committed in outer space is subject to jurisdiction in the country that owns the space craft in which the killing transpired. In the event the murder occurred on an extraterrestrial planet (e.g. the ), no country can own land of any other planet so the killer is bound by the laws of the country in which they originate. This also applies to the per agreement signed by all countries that have worked on the station so all astronauts are covered.
