I asked Joseph Kennedy, who teaches criminal law at UNC at Chapel Hill, what he thought about this statement from Elizabeth Scheibel, the prosecutor in the Phoebe Prince case, in response to my piece : "As a matter of law, the existence of a victim's disability does not legally excuse a defendant's criminal actions. Under many statutory schemes it serves to aggravate the offense, rather than mitigate it."
For all the legally minded folk out there, here is Kennedy’s interesting and helpful response:
That is true, as far as it goes, but is also true that the prosecutor must prove that the defendant was also a cause in fact and a proximate cause of any result required for an offense. This is what a leading treatise says about suicide and causation:
What then, of suicide by the victim? If A wounds B with intent to kill, but thereafter C shoots B with intent to kill and does kill him instantly, we know that A is not the cause of B's death. If, instead, B takes his own life, we again have a d eliberate act directed toward killing B that has intervened, so one might expect the same result. Such a result is certainly appropriate when B commits suicide from some motive unconnected with the fact that he is wounded, but suicide in not abnormal when B acts out of the extreme pain of wounds inflicted by A or when the wound has rendered him irresponsible. Although voluntary harm-doing usually suffices to break the chain of legal cause, this should not be so when A causes B to commit suicide by creating a situation so cruel and revolting that death is preferred." From Wayne LaFave’s Criminal Law (5th ed.)
Note the limitations. Voluntary harm-doing ordinarily cuts off causation. If suicide is an abnormal response to the injury, then no causation. The egg-shell crime victim [the concept of the extra-fragile victim, from tort law] usually involves a particular susceptibility to physical injury (i.e. a hemophiliac bleeding to death). Suicide in response to insults would ordinarily be considered unforeseeable and thereby outside of proximate causation. Similar issues also arise with respect to the mental state of the defendant. A defendant who did not know of a victim's particular vulnerability might not have the mental state of knowingly (or perhaps even recklessly or negligently) causing a certain result.