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Murder

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Key facts: Murder requires an unlawful killing with malice aforethought, is generally divided into degrees that vary by state, and under federal law carries a possible sentence of death or life imprisonment for first-degree murder.[1][3]

Murder is the unlawful killing of another person, traditionally defined as a killing committed with malice aforethought.[1]It is a category of homicide, since not every homicide is unlawful or amounts to murder.[2]Most states divide murder into degrees, and federal law separately defines murder for killings within federal jurisdiction.[3]

Definition

Murder is when a person unlawfully kills another person, and it is a category of homicide rather than a synonym for it, since not all homicide is unlawful.[1]Homicide is simply a manner of death in which one person causes the death of another, through action or inaction, and includes lawful killings justified by defenses such as self-defense.[2]The precise legal definition of murder varies by jurisdiction, and most states distinguish between degrees of murder, while some states instead rely on the Model Penal Code's definitions.[1]Readers wanting background on how crimes are defined generally may review the elements of a crime and the role of mens rea.

Malice aforethought

At common law, murder was defined as killing another human being with malice aforethought, a legal term of art covering several types of culpable mental states.[1]These included intent-to-kill murder, grievous-bodily-harm murder (where the defendant intended serious harm but not death), felony-murder, and depraved-heart murder, which involves killing in a way that shows callous disregard for human life, such as firing a gun into a crowded room.[1]The Model Penal Code moved away from the traditional malice-based approach, defining murder instead as purposefully or knowingly killing another person, or killing under circumstances showing extreme recklessness.[1]Federal law also frames murder in these terms, defining it as the unlawful killing of a human being with malice aforethought.[3]

First-degree murder

Under what is sometimes called the Pennsylvania Method, certain specified types of killing are classified as first-degree murder, historically the only type carrying the death penalty.[1]First-degree murder typically includes willful, deliberate, and premeditated killing, particularly heinous methods such as poisoning or ambush, and felony-murder limited to certain listed felonies such as arson, rape, robbery, and burglary.[1]Federal law follows a similar structure, defining first-degree murder to include killing by poison, lying in wait, or any other willful, deliberate, malicious, and premeditated killing, as well as killings committed during the perpetration of specified felonies such as arson, kidnapping, robbery, and burglary.[3]Both first- and second-degree murder are intentional homicide offenses, distinguished chiefly by their mental state.[2]

Second-degree murder

Second-degree murder typically includes killings committed with malicious intent but without premeditation.[1]Under federal law, any murder that does not meet the specific criteria for first-degree murder is classified as murder in the second degree.[3]A small number of states, including Florida, Pennsylvania, and Minnesota, also recognize a separate category of third-degree murder covering other unintentional killings that do not fit first- or second-degree definitions.[1]

Felony murder

The felony murder rule allows a person to be charged with murder if a death results from the commission of a violent felony, even without intent to kill.[4]Violent felonies typically include burglary, robbery, arson, rape, and kidnapping, though some states expand the rule, and a few, such as Georgia and Missouri, apply it to all felonies.[4]Under the merger doctrine, the rule does not apply when the underlying felony is itself assaultive in nature and would otherwise constitute the elements of murder.[4]The Supreme Court has held that the Eighth Amendment bars the death penalty for a co-felon who did not intend anyone to be killed, but permits it where the co-conspirator showed reckless indifference to human life and played a major role in the felony.[4]Readers may also find background on related offenses at violent crimes and on constitutional punishment limits at Eighth Amendment: bail, fines and punishment.

Murder vs manslaughter

Manslaughter is the unlawful killing of another person without malice, making it a less culpable offense than murder.[5]It is traditionally divided into voluntary manslaughter, an intentional killing in the heat of passion in response to adequate provocation, and involuntary manslaughter, a negligent killing.[5]The Model Penal Code similarly treats manslaughter as including reckless homicide and homicide that would otherwise be murder but was committed under extreme mental or emotional disturbance for which there is reasonable explanation.[5]Federal law tracks this same voluntary/involuntary division, defining manslaughter as an unlawful killing without malice.[6]

Federal murder law

Federal law defines murder as the unlawful killing of a human being with malice aforethought and applies within the special maritime and territorial jurisdiction of the United States.[3]The federal statute lists specific circumstances that make a killing first-degree murder, including premeditated killing and killing during the commission of certain felonies, while classifying all other murders as second-degree.[3]Federal manslaughter law separately punishes voluntary and involuntary manslaughter committed within that same jurisdiction.[6]General information on how federal offenses differ from state crimes is available at federal crimes.

Penalties

Under federal law, a person convicted of first-degree murder within the special maritime and territorial jurisdiction of the United States may be punished by death or by imprisonment for life, while a person convicted of second-degree murder may be imprisoned for any term of years or for life.[3]Federal manslaughter penalties are lower: voluntary manslaughter carries a fine or imprisonment of not more than 15 years, or both, and involuntary manslaughter carries a fine or imprisonment of not more than 8 years, or both.[6]Because the definitions and punishments for murder vary by state, and some states use different degree systems or the Model Penal Code, penalties outside the federal system differ by jurisdiction.[1]Those facing charges may wish to review general information at Charged with a crime? Start here and on sentencing at criminal sentencing.

Common questions

What is the difference between first- and second-degree murder?

First-degree murder typically requires a willful, deliberate, and premeditated killing, or a killing committed during certain serious felonies, while second-degree murder covers killings with malice but without premeditation.[1]Federal law follows the same basic split, defining specific premeditated or felony-related killings as first-degree murder and treating any other murder as second-degree.[3]

Can you be convicted of murder if you didn't kill anyone?

Yes, under the felony murder rule, a person can be charged with murder if a death occurs during the commission of a violent felony, even if that person did not cause the death and had no intent to kill.[4]For example, if two people attempt a robbery and one accidentally kills an employee, both participants may be charged with murder under the rule.[4]

What is the difference between murder and manslaughter?

Murder requires malice aforethought, while manslaughter is an unlawful killing committed without malice and generally involves less culpability.[5]Manslaughter is divided into voluntary manslaughter, an intentional killing in the heat of passion after adequate provocation, and involuntary manslaughter, a negligent killing, and sentences for manslaughter are usually less severe than for murder.[5][2]

Is homicide the same thing as murder?

No, homicide is a broader category referring to any death caused by another person, whether through action or inaction, and includes lawful killings such as those justified by self-defense.[2]Murder is only the subset of homicide that is unlawful and committed with the required intent or malice.[1]

Does every state define murder the same way?

No, the precise legal definition of murder and its degrees varies by jurisdiction, and while most states use a degree system similar to the Pennsylvania Method, some rely instead on the Model Penal Code.[1]Only a few states, such as Florida, Pennsylvania, and Minnesota, recognize third-degree murder as a separate category.[1]

References

All sources retrieved November 2026.

  1. ^ a b c d e f g h i j k l m n o p q r "Murder (Wex)". Legal Information Institute, Cornell Law School. Retrieved November 2026.
  2. ^ a b c d e "Homicide (Wex)". Legal Information Institute, Cornell Law School. Retrieved November 2026.
  3. ^ a b c d e f g h i j k "18 U.S.C. § 1111". U.S. Code via Legal Information Institute. Retrieved November 2026.
  4. ^ a b c d e f g "Felony murder rule (Wex)". Legal Information Institute, Cornell Law School. Retrieved November 2026.
  5. ^ a b c d e f "Manslaughter (Wex)". Legal Information Institute, Cornell Law School. Retrieved November 2026.
  6. ^ a b c "18 U.S.C. § 1112". U.S. Code via Legal Information Institute. Retrieved November 2026.