Definition
A category of homicide in which the killing of a human being is legally excused from criminal guilt, though not entirely free from moral or legal fault. Unlike justifiable homicide — which involves no fault whatsoever — excusable homicide acknowledges some degree of blame in the actor, but finds that blame too slight to warrant criminal punishment as a felony.
At common law, excusable homicide was divided into two recognized forms:
1. Homicide per infortunium (by misadventure): A killing that occurs when a person is performing a lawful act, without intent to harm, and death results accidentally. If the underlying act was unlawful, the killing was typically elevated to manslaughter, removing it from the excusable category.
2. Homicide se defendendo (in self-defense): A killing that occurs in the course of a sudden affray, where the defender uses force to protect against an attack. Crucially, this form of self-defense at common law was distinguished from fully justifiable self-defense: the actor bore some share of responsibility for the confrontation, making the killing excusable rather than entirely without fault.
The defining characteristic of excusable homicide is this partial fault. As Bouvier states, the necessity rendering the killing excusable "may be said to have been partly induced by his own act." The law forgives the outcome without declaring the actor wholly blameless.
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Common Confusion
Excusable homicide is frequently conflated with justifiable homicide, but the distinction carries real legal weight — particularly in historical sources. Justifiable homicide involves no fault on the part of the killer; the killing is affirmatively sanctioned by law (as in lawful execution or, in many formulations, defense of another without provocation). Excusable homicide involves a killing where the actor bears some contributing fault, but that fault is deemed insufficient to constitute a crime. In modern American criminal law, many jurisdictions have collapsed or blurred this distinction, treating certain self-defense killings as fully justifiable without the historical fault analysis. Researchers working in pre-twentieth-century sources must be careful not to map modern self-defense doctrine backward onto the common law excusable/justifiable divide.
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Recognized Forms
/SUBTYPES
Per Infortunium (By Misadventure): Death resulting from a lawful act performed without harmful intent. The lawfulness of the underlying act is the essential qualifier — death caused during an unlawful act was not misadventure but manslaughter.
Se Defendendo (In Self-Defense): Death resulting from force used during a sudden affray, where the defendant contributed to the situation but did not act with murderous intent. At common law, this carried residual consequences (including forfeiture of goods in some periods) even though the killing was excused from felony punishment.
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Why It Matters in Research
The primary research trap with excusable homicide is the term's gradual obsolescence. Modern criminal codes rarely use the phrase. Most American jurisdictions have restructured homicide law around statutory categories — murder, manslaughter, negligent homicide, vehicular homicide — that do not map cleanly onto the common law excusable/justifiable division. A researcher reading a nineteenth-century case discussing whether a killing was "excusable" is operating in a different doctrinal framework than one reading a modern state statute.
The se defendendo category is particularly treacherous. At common law, even an excused self-defense killing could trigger forfeiture of the defendant's goods — a civil consequence that survived the criminal excuse. Sources that appear to discuss "self-defense" without this nuance may be describing a different doctrine than the one being researched.
Researchers working on vehicular or negligent homicide cases should note that the per infortunium category is the doctrinal ancestor of modern negligent and vehicular homicide statutes, though the transformation is incomplete and the lineage is not always acknowledged in modern opinions. The Law Mind Encyclopedia entries on negligent homicide and causation issues are directly relevant to tracing this evolution.
Jurisdictional variation in how courts drew the line between excusable and justifiable — and later between excusable homicide and manslaughter — is significant. Small differences in how the "lawful act" requirement was applied produced divergent results across American states and between American and English sources.
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Historical Dictionary Support
The four source dictionaries substantially agree on the core definition but illuminate different aspects of the doctrine.
Black's and Burrill's follow Blackstone's formulation directly (4 Bl. Comm. 182), characterizing excusable homicide as deserving "some little degree of punishment" in strictness, even though it is excused from felony guilt. This formulation — fault acknowledged, felony waived — is the conceptual spine of the category.
Rapalje & Lawrence provide the most operationally useful account, detailing both subcategories and specifying the critical rule: if death ensues from an unlawful act, the offense rises to manslaughter and exits the excusable category. This is the line researchers must watch in historical case analysis.
Bouvier offers a different emphasis, defining excusable homicide by the concept of induced necessity — the killing is excused because the actor was partly responsible for creating the circumstances requiring it. This framing is closer to modern comparative fault reasoning and explains why some jurisdictions historically treated se defendendo killings as less than fully justified even when legally excused.
What the historical dictionaries collectively miss is the practical obsolescence of the category. None addresses how American statutory codification would eventually absorb and transform both subcategories. Researchers who rely solely on these definitions without checking whether the jurisdiction adopted statutory homicide classifications may reach anachronistic conclusions about how courts applied the doctrine.
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Jurisdictional Note
Most American states no longer use "excusable homicide" as a formal statutory category, though the phrase persists in some older codes and occasional case law. In jurisdictions that retain the term, its scope and the treatment of the underlying fault element varies. English common law sources, which inform all four historical dictionaries, applied forfeiture consequences to excusable (but not justifiable) homicide that were not uniformly adopted or later were abolished in American jurisdictions.
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Encyclopedia Cross-Reference
Homicide — Negligent Homicide (The Law Mind Criminal Law Encyclopedia)
Homicide — Vehicular Homicide and Manslaughter (The Law Mind Criminal Law Encyclopedia)
Homicide — Causation Issues in Homicide Cases (The Law Mind Criminal Law Encyclopedia)
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