The effect of pre-identification warnings and post-identification feedback on eyewitness confidence and other testimony-relevant judgments

Abstract

False eyewitness identification is a primary cause of wrongful convictions of innocent suspects. Studies demonstrate that case investigators can influence the confidence and testimony-relevant judgments of eyewitnesses during lineup procedures. Confirming feedback delivered by case investigators was shown to inflate eyewitnesses’ reports. Disconfirming effect was shown to deflate these retrospective reports in some studies, but had no effect in other studies. Research also shows that subjective testimony-relevant judgments but not the objective testimony-relevant judgments are influenced by the post-identification feedback. The present study explored whether the effect of post-identification feedback on eyewitness confidence and subjective testimony-relevant judgments is eliminated after eyewitnesses receive a strong cautionary statement against any undue influence before attempting to identify the suspect from a lineup. The study is the first to investigate the post-identification feedback effect in Lebanon. There are still no laws or guidelines on lineup procedures, so the study advises the Lebanese judicial system on the effect of post-identification feedback by case investigators. The study followed a 3 (Post-identification Feedback: confirming, disconfirming, neutral feedback) × 2 (Pre-identification warning: warning, no warning) × 2 (Gender: male, female) between-participants experimental design on eyewitness confidence and subjective testimony-relevant judgments. Seventy male students and 42 female students at the American University of Beirut were administered the lineup procedure on a computer screen. Participants watched a staged crime video, received biased instructions and the pre-identification warning, identified the suspect from a five-person target-absent lineup, received the post-identification feedback, and responded to a 13-item questionnaire and to the manipulation check sheet. As predicted, confirming feedback inflated eyewitnesses’ confidence and subjective testimony