DNA and the changing face of justice

Focusing on the impact of DNA evidence in jury trials, evidence for the existence of multiple posited forms of the “CSI effect” is reviewed. The most popular version of the effect, that it produces unrealistic expectations of the prosecution and thus results in unwarranted acquittals, remains unsupported. The converse effect, that unwarranted convictions result from the overweighting of DNA expert evidence, has received some support from archival analyses, a substantial field study, and several simulation studies. The precise factors that produce these trends are yet not well-understood. Future research should examine the source of these findings, explore ways to assist jurors in according DNA evidence appropriate probative weight, and take into account the influence of jury deliberations.