The Influence of Familiar and Confident Eyewitnesses on Mock Jurors’ Judgments

Abstract

We examined whether eyewitness confidence, familiarity with the defendant (defined as number of prior exposures), and eyewitness age (Study 1 only) influenced mock jurors in a murder trial. Participants read a criminal mock trial transcript where the eyewitness reported seeing the defendant once or many times (vs. none) and answered questions relating to the defendant’s guilt, culpability, and the accuracy of the eyewitness’ identification. In Studies 1 and 2 (N = 542 and N = 169, respectively) only confidence influenced jurors’ judgments with more guilt judgments and higher likelihood of identification accuracy when the witness espoused high (vs. low) confidence. Study 3 (N = 179) utilized a stronger operationalization of familiarity by explicitly stating the number of times the eyewitness had seen the defendant prior to the crime (e.g., 0, 10, or 20 times). Mock jurors were more likely to believe that the defendant was guilty when the eyewitness had seen him 10 times prior to the crime compared to zero times. Additionally, there was a trend for more favorable perceptions of the eyewitness as familiarity with the defendant increased. These results suggest that in some cases, familiarity between an eyewitness and defendant can impact mock juror decision-making.