From prior record to current verdict: How character evidence affects jurors' decisions

This research examined whether a defendant's prior conviction for a similar crime significantly influences mock jurors' individual verdicts for six crimes (shoplifting, attempted rape, theft, robbery, prostitution and child molestation). Using data from 365 students, a series of models was tested to determine whether mock jurors' attributions about a defendant's credibility and criminal propensity mediate the impact of a prior conviction on the verdict. Subjects' threshold of conviction (assessed by measuring their degree of regret at the prospect of an erroneous verdict) was also tested as a potential mediator of the prior-verdict relationship. Logistic regressions revealed that propensity attributions were a significant complete or partial mediator for all six crimes, whereas credibility attributions were rarely a significant mediator, and threshold of conviction did not mediate the impact of a prior conviction for any crime.; The results also reveal that jury instructions on the legally appropriate use of prior convictions evidence had no significant effect on jurors' attributions or their verdicts. Several reasons for the inefficacy of instructions in this research are discussed.; The results demonstrate that a defendant's possession of a prior conviction for a crime similar to the current offense increases the odds of his conviction significantly, and that this occurs at least partially by increasing jurors' perceptions of the defendant's criminal propensity. The fact that attributions of propensity commonly served to mediate the impact of a defendant's prior conviction on the verdict clearly suggests that jurors do not use such evidence in a legally appropriate manner, such as to assess the defendant's credibility, but instead use prior convictions evidence to attribute criminal propensity to the defendant.