Abstract
At the conclusion of the penalty phase—after the evidence is heard, the closing arguments given and the instructions read—the jurors enter the jury room faced with a binary choice: each juror must decide whether the defendant should live or die. Unlike the decision the jurors made during the guilt-or-innocence phase of the proceedings, however, this decision is not, at its core, a determination of fact, for example, did the defendant “do it,” but a moral and normative choice—does he deserve to die? While there are antecedent factual determinations jurors must make, including the existence of a statutory aggravating circumstance, the final decision the jurors must make is not factual in nature. As the courts have noted, this is an “awesome responsibility,” and the jury must make a “reasoned moral” decision whether life imprisonment without the possibility of parole or the death penalty is the appropriate punishment. It is also an awesome responsibility to shape the defendant’s case for life. The job of defense counsel is to provide the jury with the most sympathetic facts and the most persuasive interpretation of the relevant facts. Our understanding of how this task can be accomplished has changed remarkably in the last twenty-five years, in large part because of the data that is now available about how juries think about the