Also known as: mala prohibita · wrong because prohibited
Written by attorneys · grounded in primary & secondary sources — see below
A category of offense consisting of conduct that is criminal solely because a statute or regulation prohibits it. The conduct itself carries no inherent moral wrongfulness. Courts often apply a foreseeability requirement when such an offense serves as the predicate for involuntary manslaughter liability.
Dr. Lang parked her car in a marked ambulance bay at the hospital to save time. An arriving ambulance carrying a heart-attack patient had to wait outside, delaying treatment and causing the patient's death. Prosecutors charged her with misdemeanor manslaughter. Because the parking ordinance is malum prohibitum, the court required proof that the death was a foreseeable consequence of the violation before liability could attach.
Mason McCarthy drove with a suspended license after failing to pay a fine. While obeying all traffic rules, he struck and killed a pedestrian. The license suspension was a regulatory malum prohibitum offense. The court held that the death was not a foreseeable result of the licensing violation alone, so no manslaughter liability followed.
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Mariam Mansour flew a camera drone indoors at a crowded party in violation of a civil aviation regulation. The drone malfunctioned and struck a guest, causing fatal injury. The regulatory ban on indoor operation is malum prohibitum. Liability for manslaughter turned on whether a reasonable person would have foreseen the risk of a fatal crash from the violation.
Marcus Mitchell secured propane tanks loosely on his food truck instead of following the required cage ordinance. A jostle caused a tank to leak and explode, killing a customer. The safety regulation is malum prohibitum. The court examined whether the explosion was a natural and foreseeable consequence of the regulatory breach.
Monica Morgan took ten passengers on a boat limited to six under harbor regulations. In choppy water the vessel capsized and a passenger drowned. The passenger-limit rule is malum prohibitum. Manslaughter liability depended on whether the drowning was a foreseeable result of exceeding the regulatory capacity.
Malcolm McKinley ordered crane lifts over a public sidewalk after curfew in violation of a city construction ordinance. A load fell and struck a pedestrian. The time-and-location restriction is malum prohibitum. The court assessed whether the death was a natural consequence of the regulatory violation before imposing manslaughter liability.
Malum prohibitum offenses are wrong only because a statute forbids them. Malum in se offenses are inherently wrongful regardless of statutory prohibition. The distinction affects whether an offense can serve as the predicate for misdemeanor manslaughter without additional proof of foreseeability.
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Most courts require that the resulting death be a foreseeable or natural consequence of the unlawful conduct. Mere coincidence between the violation and the death is insufficient. The requirement prevents automatic liability for regulatory offenses that carry no inherent danger.
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Regulatory malum prohibitum offenses are often treated as public-welfare crimes that may dispense with traditional mens rea. Courts still examine whether the statute's purpose and penalties justify strict liability. The classification alone does not automatically eliminate an intent requirement.
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Some courts examine the degree of the violation or the risk created. Speeding slightly may remain malum prohibitum while extreme speeding may be viewed as malum in se. The reclassification turns on whether the conduct itself demonstrates inherent danger or moral wrongfulness.
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…abandonment of the ingredient of intent, not merely with considerations of expediency in obtaining convictions, nor with the malum prohibitum classification of the crime, but with the peculiar nature and quality of the offense. We referred to “. . . a now familiar type of legislation whereby penalties serve as effective means of…