Two experiments were conducted to distinguish between inability to disregard information and biased predisposition as explanations for authoritarians' trial decisions. In the first experiment, 120 mock jurors rendered verdicts and gave probability of guilt estimates for trial evidence involving two levels of admissibility of wiretap evidence (inadmissible and admissible) and two levels of incrimination value of wiretap evidence (exonerating and incriminating). Results supported a pro- and antidefendant bias rather than a differential cognitive ability model. The second experiment was conducted to determine whether repeating and emphasizing judge's instructions to jurors to disregard inadmissible evidence would reduce authoritarians' tendency to incorporate it. Authoritarian subjects were more likely to convict, especially in the presence of incriminating evidence, regardless of its admissibility and regardless of judge's emphasis. Tables, 1 note, and 26 references are supplied. (Author abstract modified)