Some crimes require the prosecution to prove that the defendant caused a particular result. Proving this fact is usually not difficult. However, challenging issues of causation sometimes occur in the criminal law, most frequently in homicide cases because homicide requires the prosecutor to prove the defendant caused the death of another human being. (See Chapter 8.)
Causation often can be established by showing that the defendant’s action directly brought about the resulting harm. In most cases causation is simply a question of physical occurrence. Did the defendant initiate physical forces that, according to the laws of nature, led to a particular result?
Establishing that the defendant’s conduct caused the proscribed result ordinarily is not difficult. If a professional killer shoots the victim in the head and the victim dies, a pathologist can conduct an autopsy and then testify at trial that the bullet fired by the defendant brought about the victim’s death by producing massive injury to the victim’s brain. Because the defendant produced the victim’s death in exactly the manner he intended, there is no controversy about his criminal responsibility for causing death. Likewise, when a defendant engages in risky conduct that brings about death in exactly the way his conduct made probable, proving that the defendant’s conduct caused the prohibited result is not hard. The actor is rightly blamed for the predictable consequences of natural events that he intentionally set in motion.
However, as in all human experience, the unusual or unexpected sometimes happens. What if the defendant did not intend or anticipate the harm, or the harm occurs in an improbable manner? Is she criminally responsible for that harm? Judges, juries, and especially law students have difficulty determining when the criminal law will conclude the defendant has “caused” the harm and when she did not. In such cases, what started out as a simple inquiry into what caused a physical occurrence often requires a moral judgment as well.
The analytic tools developed by the criminal law to resolve difficult causation issues are not always clear or easy to apply. This doctrinal difficulty is prompted, in part, by the ongoing debate concerning the relevance of harm in determining and grading criminal responsibility.
Utilitarians are less concerned with the occurrence of harm than some retributivists. Some utilitarians argue that the defendant’s attitude toward harm—not the causation of harm—is critical in determining whether he needs to be punished. They point out that whether harm occurs is often a matter of luck or skill and that the dangerousness of the individual is the same regardless of what harm his conduct actually causes.