MURDER

Definition

The unlawful killing of a human being with malice aforethought. Murder is the most serious category of criminal homicide and is distinguished from lesser homicide offenses by the presence of malice — a mental state that encompasses not only express intent to kill but also intent to cause serious bodily harm, extreme recklessness (depraved heart), and, under the felony murder rule, the commission of certain dangerous felonies. Modern American law typically divides murder into degrees: 1. First-degree murder: A killing that is willful, deliberate, and premeditated, or that occurs during the commission of specified felonies (felony murder). Premeditation does not require extended planning — courts have found it satisfied by a moment of reflection — but it must be more than the bare intent to kill. 2. Second-degree murder: An intentional killing without premeditation and deliberation, or a killing resulting from conduct showing extreme indifference to human life (depraved heart murder). The residual category for malicious homicides that do not satisfy first-degree requirements. 3. Felony murder: A killing — by any participant in the felony, and in some jurisdictions even by a resisting victim or police officer — that occurs during the commission or attempted commission of a predicate felony. Intent to kill is not required; the malice is legally imputed from the intent to commit the underlying felony. ---

Common Language

Modern common usage (Wiktionary): "The crime of killing a person unlawfully, especially with predetermination." Historical common usage (Webster's 1913): "The offense of killing a human being with malice prepense or aforethought, express or implied; intentional and unlawful homicide." In ordinary speech, murder and killing are often used interchangeably, and the word carries a strong connotation of deliberate, intentional action. The legal definition diverges in two important directions: malice aforethought is a term of art that encompasses reckless states of mind well short of conscious intent to kill, and the felony murder doctrine extends liability to participants in dangerous felonies even when no one intended any death at all. A researcher importing the common meaning of "murder as intentional killing" into historical legal sources will misread a significant portion of the doctrine. ---

Common Confusion

MURDER vs. MANSLAUGHTER: The line between murder and manslaughter is one of the most litigated distinctions in criminal law. Both are criminal homicide; the difference lies in malice. Voluntary manslaughter typically involves an intentional killing in the heat of passion upon adequate provocation — circumstances that negate the cool deliberation associated with malice. Involuntary manslaughter involves an unintentional killing through criminal negligence or during an unlawful act not amounting to a felony. Historical sources often use "homicide" as the genus and draw the murder/manslaughter distinction through the presence or absence of malice; modern sources restructure that analysis through degree statutes, which can create apparent contradictions when reading across eras. MURDER vs. HOMICIDE: Homicide is the broader genus — any killing of a human being by another. Murder is one species of criminal homicide. Not all homicide is murder; justifiable homicide (self-defense, execution of legal process) and excusable homicide carry no criminal liability. Historical dictionaries frequently define murder within an entry on homicide, and corpus researchers should treat the two terms as hierarchically related, not synonymous. ---

Core Elements

Under the traditional common law formulation preserved in most historical dictionaries, murder requires: 1. A killing — the death of a human being caused by the defendant's act or omission. 2. Of a human being in being — historically excluding the unborn; modern statutes vary significantly on fetal homicide. 3. Unlawfully — without legal justification or excuse, distinguishing murder from lawful killings. 4. With malice aforethought — the critical element, which may be: - Express: actual intent to kill. - Implied: intent to cause grievous bodily harm; extreme recklessness (depraved heart); or, under the felony murder rule, intent to commit a predicate felony. The "under the king's peace" limitation in English common law sources was a jurisdictional and status-based qualifier excluding enemy combatants in time of war. American law dropped the crown-centered formulation but retained the substance. ---

Recognized Forms

/SUBTYPES First-degree murder: Premeditated and deliberate killing; killing by specified means (poison, lying in wait, torture in some statutes); felony murder during enumerated felonies. Second-degree murder: Intentional but unpremeditated killing; depraved heart murder; felony murder during non-enumerated dangerous felonies (in jurisdictions that extend the rule beyond first-degree predicates). Felony murder: Homicide causally connected to the commission of a predicate felony, with malice imputed by operation of law. Subject to ongoing legislative and judicial contraction in many jurisdictions. Capital murder: A statutory category in death-penalty jurisdictions identifying murders with aggravating factors that make the defendant eligible for the death penalty. Not a separate common law category. ---

Why It Matters in Research

The degree structure is a statutory invention, not a common law inheritance. At common law, all murder was a single offense carrying mandatory death. The bifurcation into degrees originated with Pennsylvania's 1794 statute and spread through American jurisdictions across the nineteenth century. Historical dictionary entries — including the primary Black's and Bouvier's entries — predate or straddle this development and define murder through the common law lens of malice aforethought without the degree framework. A researcher using those definitions to interpret a modern statute, or vice versa, risks a category error. The felony murder rule appears in Wiktionary's definition and modern statutes but receives uneven treatment in historical sources. Rapalje & Lawrence's formulation (death caused by an act "commonly known to be likely to cause death or bodily harm") gestures toward constructive malice without fully developing the felony murder rationale. Burrill's entry, by contrast, reaches back to the old English meaning of murder as secret killing (murdrum), which reflects an entirely different doctrinal concern — the Norman-era presentment fine imposed on a hundred when a Norman was killed and the killer not produced. That archaic meaning is irrelevant to modern doctrine but essential for reading medieval and early modern English legal texts in the corpus. Malice aforethought is the load-bearing phrase in every historical definition and the term most likely to mislead a researcher. It does not require premeditation, spite, hatred, or planning of any duration. It is a legal term of art designating the mental states that elevate a homicide to murder, and its content has shifted across jurisdictions and eras. Cross-reference the MALICE AFORETHOUGHT entry before drawing conclusions from any historical source's use of the phrase. Researchers working with nineteenth-century American sources should note that degree statutes were not uniform. Some states adopted Pennsylvania's framework; others created their own degree structures or none at all. A case holding that a killing constituted "murder in the first degree" under one state's statute may use that label to describe conduct that another state would classify differently. The "human being in being" limitation carries live research relevance for corpus work touching abortion law, fetal homicide statutes, and wrongful death doctrine. Modern statutes in many states extend murder liability to the killing of a viable fetus or, in some cases, any fetus — a significant departure from the common law rule that historical dictionaries uniformly reflect. ---

Historical Dictionary Support

The historical sources converge on the core formula: unlawful killing of a human being with malice aforethought, express or implied. Black's (1st Ed.), Bouvier's, and Rapalje & Lawrence all reproduce variants of Coke's definition from 3 Institutes 47, and all incorporate Russell on Crimes for the "king's peace" limitation. The agreement is substantial and reflects a genuinely stable common law baseline. Burrill's stands apart. Its entry foregrounds the old English meaning of murdrum — the secret killing doctrine and the associated presentment liability — drawing on Bracton and Fleta rather than Coke. This is not error; it is a different layer of legal history. But it is a layer that bears no operational relationship to nineteenth-century American criminal law, and researchers who encounter Burrill's entry first may be misled about the term's content. Burrill acknowledges the modern meaning but treats the archaic doctrine at length, which skews emphasis for a modern researcher. Anderson's entry as supplied in the source material appears to be a misfiled entry (it defines a chancery pleading defect, not murder), and should be disregarded for this term. Black's 2nd Ed. offers the most developed definition among the historical sources, incorporating the "sound mind and discretion" qualifier, the exclusion of unborn children, and the "peace of the state or nation" reformulation that Americanizes Coke's crown-centered language. It also begins to gesture toward the degree structure without fully integrating it. Researchers should treat the 2nd Ed. entry as the most useful bridge between common law formulation and modern statutory structure among the historical dictionary sources. None of the historical dictionaries fully develops the felony murder rule as a doctrine independent of the malice analysis, which reflects the state of treatise literature at the time of their composition. For felony murder research, the historical dictionaries are a starting point only. ---

Jurisdictional Note

The degree structure, predicate felony lists for felony murder, and the mental states sufficient to constitute implied malice vary substantially across American jurisdictions and have been subject to significant legislative reform since the 1970s. Several states have abolished or severely curtailed felony murder. California's 2018–2019 statutory reforms are among the most significant recent changes to murder doctrine in any major jurisdiction. English law, which informs the historical sources heavily, diverged from American doctrine across the nineteenth and twentieth centuries and abolished the felony murder rule by statute in 1957. ---

Encyclopedia Cross-Reference

Homicide — First-Degree Murder (Premeditation and Deliberation) (The Law Mind Criminal Law Encyclopedia) Homicide — Second-Degree Murder (The Law Mind Criminal Law Encyclopedia) Homicide — Felony Murder Rule (The Law Mind Criminal Law Encyclopedia) ---

Related Terms