The influence of prior record evidence on juror decision making

Several researchers have investigated the impact of evidence of prior convictions on jurors' decision making. Very little is known about a related issue, the impact of prioracquittal evidence introduced by the prosecution on jurors' decisions. The Supreme Court recently held (Dowling v. U.S., 1990) that the admission of prior acquittal evidence does not unfairly prejudice the defendant. We conducted a simulation study to examine the effects of prior record evidence (prior convictions, prior acquittals, and no prior record) on jurors' decisions. We also manipulated the presence of judicial instructions on the limited use jurors can make of extrinsic acts evidence. Mock jurors were more likely to convict the defendant when they had evidence of a prior conviction than when they had evidence of a prior acquittal or no record evidence. This effect was mediated by attributions about criminal propensity. Judge's limiting instructions were ineffective in guiding jurors' use of prior record evidence.