Definition
Murder is the unlawful killing of another human being committed with malice aforethought. Malice aforethought is the mental state that distinguishes murder from the less serious offense of manslaughter. Most states divide murder into degrees—commonly first and second degree—based on factors such as premeditation, the manner of the killing, or whether it occurred during a dangerous felony.
Legal Meaning
Murder is the most serious form of criminal homicide. Every charge of murder rests on two essential ideas: an unlawful killing of a human being, and the mental state called malice aforethought. The phrase is a legal term of art that can mislead non-lawyers. It does not require hatred, spite, or careful planning in the ordinary sense. Instead, malice is satisfied in several distinct ways recognized by the common law and modern statutes.
Traditionally, malice aforethought is established by any of the following: an intent to kill; an intent to inflict serious bodily harm; a reckless and extreme indifference to the value of human life (often called a "depraved heart" or "abandoned and malignant heart"); or the intent to commit a dangerous felony during which a death results. This last category is the basis for the felony murder rule.
The grading of murder varies significantly from state to state, and federal law has its own murder statutes. Most jurisdictions divide the offense into degrees. First degree murder typically requires premeditation and deliberation or falls within a list of especially serious circumstances, while second degree murder covers intentional killings without premeditation and depraved-heart killings. Because of this variation, the same conduct may be graded differently depending on where it occurs. Murder is closely related to, but distinct from, manslaughter, which is an unlawful killing committed without malice.
Key Points
- Murder is an unlawful killing of a human being committed with malice aforethought
- Malice can be an intent to kill, intent to cause serious bodily harm, depraved-heart recklessness, or felony murder
- Most states divide murder into degrees, commonly first and second degree
- First degree murder usually requires premeditation and deliberation or other aggravating circumstances
- The felony murder rule can make a death during a dangerous felony murder even if unintentional
- Murder differs from manslaughter, which is an unlawful killing without malice
- Grading and sentencing vary by state and under federal law; some allow capital punishment for the most serious killings
- Common defenses include self-defense, lack of intent, mistaken identity, and challenges to the evidence
Real-World Example
Daniel decides over several days to kill a business rival. He buys a weapon, studies the rival's schedule, waits outside his office, and shoots him. Because the killing was planned in advance with premeditation and deliberation, a prosecutor will likely charge first degree murder.
In a separate case, three people rob a convenience store. During the robbery, one of them shoots and kills the clerk. Even the accomplices who did not pull the trigger may be charged with felony murder, because the death occurred during the commission of a dangerous felony. This illustrates how the felony murder rule can extend murder liability beyond the person who directly caused the death—though states differ widely on how far that liability reaches.
Common Degrees and Categories of Murder
| Category | Typical Description | Key Mental State |
|---|---|---|
| First Degree Murder | Planned, deliberate killing or other aggravated circumstances | Premeditation and deliberation |
| Second Degree Murder | Intentional killing without premeditation; depraved-heart killings | Intent to kill or extreme recklessness |
| Felony Murder | Death during a dangerous felony (robbery, burglary, arson, kidnapping) | Intent to commit the underlying felony |
| Capital Murder | Most aggravated killings eligible for the harshest penalties | Defined by statute with aggravating factors |
| Voluntary Manslaughter | Intentional killing in the heat of passion (not murder) | No malice; adequate provocation |
| Involuntary Manslaughter | Unintentional killing from recklessness or negligence (not murder) | No malice; recklessness or criminal negligence |
Degrees of Murder
The division of murder into degrees is a statutory innovation designed to reserve the harshest penalties for the most culpable killings. First degree murder generally requires premeditation and deliberation—evidence that the defendant formed the intent to kill and reflected on it, however briefly, before acting. Many states also designate certain killings as first degree regardless of premeditation, such as murder by poison or lying in wait, murder of a police officer, or murder committed during specified felonies.
Second degree murder is often described as the default murder category: an intentional killing committed with malice but without the premeditation that elevates a case to first degree, or a killing that results from conduct showing extreme indifference to human life. The boundary between first and second degree is defined entirely by statute and varies from state to state.
The Felony Murder Rule
Under the felony murder rule, a person can be convicted of murder when a death occurs during the commission or attempted commission of certain inherently dangerous felonies, even if the death was accidental or caused by an accomplice. The intent to commit the underlying felony substitutes for the malice that murder normally requires. Common predicate felonies include robbery, burglary, arson, rape, and kidnapping. States vary dramatically in how they apply the rule; some limit it to deaths caused by the defendants themselves, and a number of jurisdictions have narrowed or abolished it because of concerns about its harshness.
Related Terms
Facing a Homicide Charge?
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Explore Criminal DefenseWhen You Need a Lawyer
No one should face a murder investigation or charge without experienced legal counsel. A skilled criminal defense attorney can:
- Explain how murder and its degrees are defined and graded in your state
- Analyze whether the prosecution can prove malice aforethought beyond a reasonable doubt
- Challenge the cause of death, the chain of evidence, and any unlawful searches
- Raise defenses such as self-defense, lack of intent, alibi, or mistaken identity
- Seek to reduce a murder charge to manslaughter where the facts support it
- Protect your rights during interrogation, before the grand jury, and at trial
Because the penalties are so severe and the law varies by jurisdiction, contact a local criminal defense lawyer at the earliest possible moment. To understand how serious criminal matters differ from civil disputes, read our guide on civil vs. criminal cases.
Frequently Asked Questions
What is the difference between first and second degree murder?
First degree murder generally requires premeditation and deliberation, meaning the killing was planned or thought out in advance, or that it falls within a category the legislature has singled out as especially serious. Second degree murder is an intentional killing committed with malice but without premeditation, or a killing showing extreme indifference to human life. The exact line between the degrees is defined by each state's statutes and can differ significantly.
What is malice aforethought?
Malice aforethought is the mental state that distinguishes murder from manslaughter. It does not require ill will or planning in the everyday sense. It can be satisfied by an intent to kill, an intent to cause serious bodily harm, a reckless disregard for human life often called a depraved or abandoned heart, or, under the felony murder rule, an intent to commit a dangerous felony during which a death occurs.
What is the felony murder rule?
The felony murder rule allows a defendant to be convicted of murder if a death occurs during the commission of certain dangerous felonies, such as robbery, burglary, arson, or kidnapping, even if the death was unintentional. The theory is that the intent to commit the underlying felony supplies the malice. States vary widely in how broadly they apply the rule, and some have limited or abolished it.
How is murder different from manslaughter?
Murder is an unlawful killing committed with malice aforethought, while manslaughter is an unlawful killing without malice. A killing committed in a sudden heat of passion after adequate provocation is voluntary manslaughter rather than murder, and a killing caused by recklessness or criminal negligence is involuntary manslaughter. Because manslaughter lacks malice, it is graded as less serious than murder.
What penalties does a murder conviction carry?
Murder is among the most serious crimes and carries the harshest penalties, which can include lengthy prison terms, life imprisonment, and in some states and in federal cases the death penalty for the most aggravated killings. The available sentences depend on the degree of murder, aggravating and mitigating factors, and the law of the jurisdiction. Only a local criminal defense attorney can explain the potential exposure in a specific case.