Where Manslaughter Fits

Where Manslaughter Fits

Criminal homicide is graded by the mental state a killing reveals, and the first division in that grading separates murder from manslaughter. At common law, murder was the unlawful killing of a human being committed with malice aforethought.¹ That phrase is a term of art covering four mental states: an intent to kill, an intent to inflict grievous bodily harm, extreme recklessness showing a depraved, abandoned, and malignant heart, and an intent to commit a felony, which supplies the felony-murder rule.² Each of the four stays on the murder side of the line, so this chapter treats them only as the upper boundary. The phrase also departs sharply from ordinary speech. A killing need not be spiteful or planned in advance to carry malice aforethought, and in most states a person who ends a dying spouse's life at the spouse's request has committed murder.³ A reader who equates malice with ill will or advance planning will misplace borderline cases, because the term sorts killings by the kind of fault they reveal, whatever the defendant felt toward the victim.

Manslaughter begins where malice ends, and its place in the law follows from how the two crimes separated. Early common law did not distinguish murder from manslaughter, but statutes that withdrew benefit of clergy from the more heinous killings divided criminal homicide into murder, which stayed a capital crime, and the lesser offense of manslaughter.⁴ Courts defined murder through the evolving idea of malice aforethought and treated manslaughter as the residual category for every other criminal homicide, one committed without malice and without justification or excuse.⁵ The line carried enormous stakes, since the common-law rule imposed a mandatory death sentence on every convicted murderer.⁶ Manslaughter later split into voluntary and involuntary branches. At common law the two labels carried no difference in punishment, though many modern statutes grade them differently and in many states treat voluntary manslaughter as the more serious.⁷

Because manslaughter is the residual grade, involuntary manslaughter is easiest to identify by exclusion. Michigan's highest court calls it the catch-all homicide: an unintentional killing is involuntary manslaughter when it is neither murder, nor voluntary manslaughter, nor covered by a recognized justification or excuse.⁸ Each exclusion has its own content. Voluntary manslaughter is an intentional killing that would otherwise be murder but occurred in the heat of passion, after adequate provocation, and before a reasonable cooling-off period had passed.⁹ A justified killing, such as one in self-defense, is conduct the law permits or commands, and an excusable one, such as a non-negligent accident, is not criminal either.¹⁰ The word involuntary is a technical label meaning unintentional: the defendant neither intended to kill nor intended grievous bodily harm.¹¹ That absence of any intent to kill is what separates the offense from voluntary manslaughter.¹²

The proviso in the last step keeps the residual category from swallowing every unintended death. A death that careful conduct could not have prevented is an accident and no crime, so the offense still demands blameworthy conduct of a kind the next sections measure. What the residual structure settles is where a blameworthy but malice-free killing lands once the earlier questions have been answered.

The contrast with voluntary manslaughter shows how the intent question operates.

The other pole is a killing with no intent and no awareness of danger. The facts below are a stripped-down version of a scenario that returns with fuller detail at the end of this chapter.

Murder and involuntary manslaughter both require the unlawful killing of a human being, and they differ in the mental state that accompanies the killing.¹³ That shared structure makes involuntary manslaughter a lesser included offense of murder, so a prosecutor can charge murder with manslaughter as a fallback, and the parties can settle on a manslaughter plea when a murder conviction is uncertain.¹⁴ The conduct this grade covers occupies a band between two neighbors. It falls short of the extreme recklessness that makes depraved-heart murder, yet it shows more culpability than ordinary civil negligence.¹⁵ How far that band extends in each direction is the question the rest of this chapter works through.

Involuntary manslaughter reaches two kinds of conduct. The first is dangerous conduct, a killing caused by criminal negligence or, in some formulations, by recklessness.¹⁶ The second is unlawful conduct, a killing during an unlawful act that did not amount to a felony or did not fall within the felony-murder rule.¹⁷ Statutes in many states track this division, describing the offense as a killing in an unlawful act not amounting to a felony or in a lawful act done without due caution and circumspection.¹⁸ The next sections develop the dangerous-conduct route in depth, starting with how much more than civil negligence the law demands, and the unlawful-act route returns once the boundary with murder has been drawn.