a b s t r a c tShowups -when a single suspect is presented to an eyewitness -are thought to be a more suggestive procedure than traditional lineups by the U.S. Supreme Court and social science researchers. The present experiment examined the impact of retention interval on showup identifications, because immediate showups might be no worse than, and perhaps even better than, a lineup conducted after a delay. Participants (N = 1584) viewed a mock-crime video and then were presented with a showup or a simultaneous lineup, either immediately or a 48 h delay. Receiver operating characteristic (ROC) analyses revealed that a showup never resulted in better identification accuracy than a lineup. We conclude with a discussion of whether showups should ever be used.

A growing movement in the United States and around the world involves promoting the advantages of conducting an eyewitness lineup in a sequential manner. We conducted a large study (N = 2,529) that included 24 comparisons of sequential versus simultaneous lineups. A liberal statistical criterion revealed only 2 significant sequential lineup advantages and 3 significant simultaneous advantages. Both sequential advantages occurred when the good photograph of the guilty suspect or either innocent suspect was in the fifth position in the sequential lineup; all 3 simultaneous advantages occurred when the poorer quality photograph of the guilty suspect or either innocent suspect was in the second position. Adjusting the statistical criterion to control for the multiple tests (.05/24) revealed no significant sequential advantages. Moreover, despite finding more conservative overall choosing for the sequential lineup, no support was found for the proposal that a sequential advantage was due to that conservative criterion shift. Unless lineups with particular characteristics predominate in the real world, there appears to be no strong preference for conducting lineups in either a sequential or a simultaneous manner. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

Showups (a one-person identification) were compared to both simultaneous and sequential lineups that varied in lineup fairness and the position of the suspect in the lineup. We reanalyzed data from a study by Gronlund, Carlson, Dailey, and Goodsell (2009), which included simultaneous and sequential lineups, and using the same stimuli and procedures, collected new data using showup identifications. Performance was compared using ROC analysis, which is superior to traditional measures such as correct and false identification rates, and probative value measures. ROC analysis showed that simultaneous lineups consistently produced more accurate identification evidence than showups, but sequential lineups were sometimes no more accurate than showups, and were never more accurate than simultaneous lineups. These results supported prior suppositions regarding the suggestiveness of showups, revealed a misconception about the superiority of sequential lineups, and demonstrated why eyewitness identification procedures need to be evaluated using ROC analyses.

Three studies examined procedures for reducing the post-identification feedback effect. After viewing a video event, participants were then asked to identify a suspect from a target-absent photo lineup. After making their identification, some participants were given information suggesting that their identification was correct, while others were given no information about the accuracy of their identification. Some participants who received confirming feedback were also given reasons to entertain suspicion regarding the motives of the lineup administrator, either immediately (Experiment 1) or after a one-week retention interval (Experiment 2). Suspicious perceivers failed to demonstrate the confidence inflation effects typically associated with confirming post-identification feedback. In Experiment 3, the confidence prophylactic effect was tested both immediately and after a one-week retention interval. The effect of confidence prophylactic varied with retention interval such that it eliminated the effects of post-identification feedback immediately but not after a retention interval. However, the suspicion manipulation eliminated the post-identification feedback effects at both time intervals. Both theoretical and practical implications are discussed.

Two studies examined the effects of post-identification feedback, age, and retention interval on participants' memories and beliefs about memories for a videotaped event, as captured by a store surveillance camera. After viewing the video, they were then asked to identify the suspect from a target-absent photo line-up. After making their identification, some participants were given information suggesting that their identification was correct, while others were given no information about the accuracy of their identification. In both experiments participants who received confirming feedback indicated they were more confident in their identification, paid more attention to the video, and that they were more willing to testify in court than those who received no feedback. The confidence inflation effects of post-identification feedback did not vary with retention interval or age. These results are consistent with a position focusing on accessibility, which suggests that witnesses have little or no retrievable recollection of how sure they were at the time of their identification.