Whether tort law's concept of proximate cause supplies the causation standard for criminal homicide.
Holding
No. Criminal homicide requires a more direct causal connection between the defendant's conduct and the death than modern tort proximate-cause doctrine requires.
Reasoning
The Court distinguished civil negligence law from criminal law. Tort proximate cause had expanded to permit recovery whenever careless conduct could be associated with an injury, but importing that expansive standard into criminal homicide would expose defendants to punishment for deaths not sufficiently attributable to their conduct in a criminal sense.
The Court relied on Commonwealth v. Redline, which rejected tort proximate cause as the criterion for criminal homicide. The same causal standard governs murder and involuntary manslaughter; the offenses differ principally in the defendant's mental state, not in the degree of causation required.
The Court illustrated the danger of a tort-based rule with civil cases involving an illegal sale of ammunition, service of alcohol to a visibly intoxicated patron, and double parking. Those acts could be proximate causes of injury in tort, but treating them as sufficient by themselves for manslaughter liability if death followed would be unjustifiably broad.