Human Causes versus Natural Events
Crimes typically occur when an offender brings about harm to the significant interests of a victim. 1 Think about the standard felonies of the common law: homicide, assault, rape, mayhem, arson, robbery, larceny, burglary. All of these crimes leave palpable harms in their wake: someone is killed (homicide), attacked (assault), sexually violated (rape), or disfigured (mayhem). A dwelling house is set afire (arson), property is taken violently or with a threat of violence (robbery), something is taken stealthfully (larceny), or a private home is invaded with felonious intentions (burglary). These are harms that unnerve the community as well as leave the victim in a state of irreversible damage.
A special requirement of causation attends a subset of these harms. Murder or more generally homicide does not occur unless a human actor causes the death of another human being. That is, the offender must kill the victim. The offender's actions must be the force that brings about the death. Suppose Alice intends to kill Bill and drives to Bill's house ready to commit the crime; just as Alice is about to knock on Bill's door, Bill dies of a heart attack totally unrelated to Alice's criminal plan. Alice does not kill Bill. She does not cause the death. Bill's death is a natural event. It is not caused by human hand.
Of course, if Bill became frightened upon seeing Alice and then had a heart attack, Alice's coming to the door might have been the cause of Bill's death. It all depends, as we shall see, on the likelihood that Bill