The Effect of Eyewitness Confidence on Jury Verdicts in a Criminal Case

The primary purpose of this study was to examine whether inconsistencies in eyewitness statements during cross-examination diminish credibility with the jury if the witness appears confident. The independent variables were eyewitness confidence and eyewitness inconsistency, and the dependent variables are jury verdict, gender of participants, and witness performance. Numerous research studies have demonstrated that eyewitness testimony may be incorrect based on factors such as memory, weapons utilized in the crime, false identification, and the witness' age. This study introduces important factors such as confidence level of eyewitness, as well as how the gender of the juror may affect the verdict that is rendered. The hypotheses of this study are: Jurors will find the witness more credible as the confidence level increases, the gender of a juror affects eyewitness performance, and the conviction rate for male jurors will be higher compared to female jurors. Each participant was randomly shown one of four trial videos, which showed a discredited eyewitness during cross-examination who attested to being 25%, 50%, 75%, or 100% confident of seeing the defendant commit the crime. Lastly, participants were asked to complete a questionnaire that asked for their gender, the verdict they would render, and to rate the overall credibility of the witness' testimony as well as how much of a role the confidence level of the eyewitness plated in their decision. For the results, hypothesis 1 stated that jurors will find the witness more credible as the confidence level increases. In both the overall analyses and comparison of the 4 experimental groups, this hypothesis was not supported. Hypothesis 2 stated that the gender of the juror affects eyewitness performance. In the overall analysis, this hypothesis was supported, with females ranking the believability and credibility of the eyewitness as being significantly more important to their verdict decision than males. For the 4 experimental groups, no gender differences were seen in the groups that were assigned to watch the 25, 50, and 100% confidence videos; however, in the 75% confidence group, women ranked the eyewitness' credibility as significantly higher than men did. Hypothesis 3 stated that the conviction rate for male jurors will be higher compared to female jurors and both types of analyses revealed that the rendering of a guilty versus not guilty verdict was not dependent upon the participant's gender.