Science and the Death Penalty: DNA, Innocence, and the Debate over Capital Punishment in the United States

The death penalty debate in the United States has recently undergone a fundamental shift. The possibility of executing the innocent has emerged as some abolitionists' most salient argument, displacing debates over such issues as fairness, deterrence, and cost. Innocence has managed to move to the fore of the debate in part because of the success of death penalty opponents in attaching epistemological certainty to one particular category of postconviction exonerations, those vouched for by the authority of DNA evidence. We suggest that such moves are primarily rhetorical because, while DNA evidence may be more accurate and reliable than other forensic science, it still fundamentally probabilistic in nature and is prone to uncertainties at all stages of its production. Yet, because of the certainty attached to DNA evidence in public discourse, it can be used as a lever with which to challenge law's claims to truth-making authority, and to undermine public trust in the death penalty. A few abolitionists and other scholars have expressed misgivings about the abolitionist embrace of the innocence argument. We push this concern further, suggesting that both abolitionists and death penalty reformers, who seek to promote a “scientific” death penalty centered on DNA evidence, draw upon a mythologized notion of “science” as a producer of epistemic certainty.