Nicholas Scurich and Richard S. John (University of California, Irvine and University of Southern California) have posted Jurors’ Presumption of Innocence (Journal of Legal Studies, Forthcoming) on SSRN.

Here is the abstract:

The presumption of innocence explicitly forbids jurors from using official suspicion or indictment as evidence of guilt in a criminal trial. A behavioral experiment tested whether jurors follow this prescription. It revealed that, compared to when an individual had been merely named, jurors thought the individual was significantly more likely to be guilty after a detective referred the case to the district attorney, and when the individual was formally charged and thus a criminal defendant. A judicial instruction to presume innocence reduced jurors’ beliefs about the defendant’s guilt. Regression analyses indicated that jurors’ priors predicted their posteriors, and further that their priors were predictive of verdicts even after accounting for their posteriors. The findings suggest that jurors make different assumptions about the guilt of a criminal defendant prior to the introduction of evidence, and that these assumptions influence their overall evaluation of the case as well as their verdict.