So, which is it? Are death penalty cases supposed to be decided by reasonable jurors applying fixed community standards, or by jurors unhinged by a barrage of emotional pleas? At the penalty phase in the Timothy McVeigh trial, 38 "victim witnesses" described the carnage at Oklahoma City to the jury. A policeman described a small child's body in a teddy-bear shirt whose "face was gone." Others described the sight of tiny pink dresses and baby socks. Jurors were devastated and horrified.
Part of the shift, in which the penalty phase no longer represents a contest between the defendant and the state but, rather, becomes a contest between the defendant and the victims' survivors, is a result of years of advocacy by the victims-rights movement. Whereas victim-impact statements were once prohibited at trial, for example, the Supreme Court now holds them to be constitutionally permissible. Whereas the victim's family used to be almost incidental at a capital trial, they now play a central role, most notably at the penalty phase.
This shift makes perfect sense if you accept that the only real justification for capital punishment is vengeance. Executions are far too rare and too capricious to have a real deterrent effect on criminals. And the case for capital punishment as a cure for recidivism is equally supported by the prospect of life imprisonment. The real reason for capital punishment, then, is vengeance—an eye for an eye—both societal and for the victims. And whether one accepts this as a valid rationale for executing killers or not, the fact is that vengeance is an emotional response. For suffering to be matched by suffering, jurors must weigh not facts, but human pain.
Human pain is not quantifiable. And understanding the pain of another turns largely on your own experience, your own sensitivities, and the victim's eloquence—not on any accepted extrinsic yardstick. By the same token, whether a defendant deserves to live or die turns largely on what lies deep in his heart and whether there is such thing as redemption; questions that jurors may not be suited to decide with any degree of certainty. These are entirely heart, not mind, questions, so it's no surprise that the penalty phase has more to do with appeals to tears as opposed to logic.
Most of us could probably agree that we have made some of our worst personal decisions with a tissue in one hand and a glass of merlot in the other. Why, then, do we allow jurors to be inflamed by prosecutors and manipulated by defense lawyers just prior to asking them to make one of the most crucial decisions they will ever make?