The Basic Rule

The Basic Rule

In a jurisdiction that retains the misdemeanor-manslaughter rule, a death the defendant did not intend is involuntary manslaughter when it occurs in the course of a misdemeanor or other unlawful act that falls short of a felony.¹ Common law gathered these killings into a broader category of unlawful-act involuntary manslaughter, which also took in certain felonies that do not qualify for the felony-murder rule, a point taken up in the next section.² Statutes in retaining states track the old formulation closely, and California's reaches a killing “in the commission of an unlawful act, not amounting to a felony.”³ The rule is easy to state because it changes only one thing, the proof the prosecution must offer about the defendant's fault.

Ordinary involuntary manslaughter asks whether the defendant killed through criminal negligence or recklessness, which means carelessness about the risk of death serious enough to deserve punishment as a crime. A jurisdiction that keeps the unlawful-act doctrine therefore gives the prosecution two routes to the same offense. If a driver runs a red light and kills a pedestrian, the prosecution may argue that the driving was criminally negligent under the circumstances, or it may argue that the traffic violation was an unlawful act that caused the death, and on the second theory proof of criminal negligence becomes unnecessary.⁴ The second route is the one this chapter examines, and it is built from three working pieces.

Each step has its own job. The first defines the territory: a felony that qualifies for felony murder is handled under that rule, so the unlawful-act theory is the home of the lesser offenses, and the next section sorts out which of them can serve as a predicate. The second keeps the doctrine inside manslaughter, since a defendant who meant to kill or to inflict grave injury is guilty of murder and never reaches this rule. The third step is the easiest to neglect. The doctrine relaxes the fault requirement but leaves causation in place, and the causal link must run to the conduct that constitutes the offense itself. Suppose a defendant argues with the victim, then commits a battery, and the victim dies of a cerebral hemorrhage that the medical evidence cannot trace to the battery rather than to the excitement of the earlier argument. The prosecution cannot show that the misdemeanor caused the death, so the theory fails.⁸ The trap is to treat a death that merely coincides with the offense as sufficient.

The reason the rule can dispense with proof about risk lies in where it locates fault. Just as a felony resulting in death can support a murder conviction without proof of malice, a misdemeanor resulting in death can support an involuntary manslaughter conviction without proof of recklessness or negligence.⁹ Ordinary involuntary manslaughter asks whether the defendant was careless about death itself, while this theory moves the inquiry to the offense. In Comber v. United States, the en banc District of Columbia Court of Appeals explained that where the doctrine applies, the defendant's intentional commission of the misdemeanor supplies the culpability that homicide liability requires.¹⁰ Courts do not explain this as a transfer of an intent to kill, because nobody imagines the defendant intended the death. The law instead recognizes a distinct category of homicide for deaths caused while carrying out some other unlawful purpose.¹¹

The incentive logic follows from the same structure. A person who knowingly breaks the law has little claim to be surprised when harm to others results, and a rule that attaches homicide liability to a death caused during the violation gives everyone a reason to avoid unlawful conduct that can injure other people. The unlawful act works much as a statutory violation does when it establishes negligence in tort, serving as a stand-in for the missing proof of carelessness. The difference is the price of error, because here the consequence is a homicide conviction.

That same feature is the rule's weakness, since it can convict of homicide a defendant who was not careless about anyone's life. The danger grows with the number of offenses available as predicates, and the number and variety of misdemeanors have increased enormously since the early common-law era.¹² The common-law version apparently reached even some deaths arising from conduct that was morally wrongful but not criminal at all.¹³ Applications show the breadth. In State v. Hupf, a driver was convicted of involuntary manslaughter after he failed to obey a stop sign, in violation of a traffic ordinance, and killed a pedestrian, a result later superseded by statute in Delaware.¹⁴ A Michigan statute likewise exposes a driver who exceeds the limit by a single mile per hour in a construction zone, and who kills a worker, to strict liability for manslaughter carrying up to fifteen years in prison.¹⁵

Other decisions stretch the predicate in odder directions. In Reed v. State, a Texas court found manslaughter where the defendant, discovered committing adultery (a misdemeanor in Texas), killed the wronged husband while defending against his murderous attack, reasoning that the attack was a foreseeable reaction to the misconduct.¹⁶ In Commonwealth v. Mink, a defendant attempting suicide accidentally killed the fiancé who intervened to stop her, and because suicide was an unlawful act that was malum in se, the court found her guilty of manslaughter.¹⁷

Courts responded by confining the rule, because they came to regard it as too harsh. In many jurisdictions a death during a misdemeanor counts only if the offense is malum in se, meaning inherently wrong by common moral standards, rather than malum prohibitum, meaning wrong only because a law forbids it.¹⁸ Most courts require either that the misdemeanor be malum in se or, for an offense that is malum prohibitum, that the death be a foreseeable or natural consequence of the unlawful conduct.¹⁹ Others ask whether the misdemeanor was dangerous under the circumstances, and many states, led by the Model Penal Code, have abolished the doctrine outright.²⁰ Those limits occupy a later section, and the next section first asks which offenses can serve as the predicate unlawful act.