Mock jurors’ evaluations of eyewitness identification evidence based on appearance change and associated instructions

It is common for a perpetrator's appearance to change between committing the crime and later appearing in an identification procedure. The present study investigated how such appearance change (AC) would be evaluated by potential jurors, as well as tested mock jurors' evaluations of the appearance change instruction (ACI) utilized by police. Recent research indicates that the ACI harms eyewitness identification accuracy and limits the predictive nature of confidence, but would mock jurors' estimates of suspect guilt reflect this? In Experiment 1, AC reduced suspect guilt estimates, but the ACI eliminated this effect, indicating that potential jurors may not discount an identification if made after ACI. Experiment 2 introduced a hypothetical eyewitness expert who informs participants about the research that both AC and the ACI harm eyewitness performance. We also compared two types of expert instructions based on recent mock jury research: simple versus reason-based. Both types served to reduce suspect guilt estimates associated with AC. Participants still trusted the ACI even with expert instructions, but not as much as when there was no expert. Lastly, we also manipulated eyewitness confidence level, supporting recent research that manipulations have no effect on suspect guilt estimates when confidence is low (i.e. uncertainty trumps).