Eyewitness Accuracy Rates in Police Showup and Lineup Presentations: A Meta-Analytic Comparison

Meta-analysis is used to compare identification accuracy rates in showups and lineups. Eight papers were located, providing 12 tests of the hypothesis and including 3013 participants. Results indicate that showups generate lower choosing rates than lineups. In target present conditions, showups and lineups yield approximately equal hit rates, and in target absent conditions, showups produce a significantly higher level of correct rejections. False identification rates are approximately equal in showups and lineups when lineup foil choices are excluded from analysis. Dangerous false identifications are more numerous for showups when an innocent suspect resembles the perpetrator. Function of lineup foils, assessment strategies for false identifications, and the potential impact of biases in lineup practice are suggested as additional considerations in evaluation of showup versus lineup efficacy.     

Repeated Eyewitness Identification Procedures: Memory,Decision Making,and Probative Value

Two experiments examined the effects of multiple identification procedures on identification responses, confidence, and similarity relationships. When the interval between first and second identification procedures was long (Experiment 1), correct and false identifications increased, but the probative value of a suspect identification changed little; consistent witnesses were more confident than inconsistent witnesses; and the similarity relationships between suspect and foils were unchanged. When the interval between first and second identification procedures was short (Experiment 2), suspect identification rates changed little, but foil identifications increased significantly; confidence for all identifications increased; consistent witnesses were more confident than inconsistent witnesses; and similarity relationships changed such that witnesses were less likely to identify the suspect as being the best match to the perpetrator.     

Age differences (or lack thereof) in discriminability for lineups and showups

Previous research reveals that showups are an inferior eyewitness identification procedure to lineups, but no single study has compared younger and older adults' identification decisions for both of these procedures. We had witnesses watch a mock crime video and then make an identification decision from a fair lineup, a biased lineup, or a showup that contained the perpetrator or a designated innocent suspect. Receiver operating characteristic (ROC) analysis showed that identification accuracy was higher from a lineup than from a showup for both age groups, even if the lineup was biased. In addition, calibration curves revealed that witnesses were underconfident when choosing from a fair lineup but overconfident when choosing from a showup. These results reinforce prior research asserting the superiority of lineups over showups.     

The Effect of Exposure to Multiple Lineups on Face Identification Accuracy

This study examines the conditions under which an intervening lineup affects identification accuracy on a subsequent lineup. One hundred and sixty adults observed a photograph of one target individual for 60 s. One week later, they viewed an intervening target-absent lineup and were asked to identify the target individual. Two days later, participants were shown one of three 6-person lineups that included a different photograph of the target face (present or absent), a foil face from the intervening lineup present or absent), plus additional foil faces. The hit rate was higher when the foil face from the intervening lineup was absent from the test lineup and the false alarm rate was greater when the target face was absent from the test lineup. The results suggest that simply being exposed to an innocent suspect in an intervening lineup, whether that innocent suspect is identified by the witness or not, increases the probability of misidentifying the innocent suspect and decreases the probability of correctly identifying the true perpetrator in a subsequent test lineup. The implications of these findings both for police lineup procedures and for the interpretation of lineup results in the courtroom are discussed.     

Accuracy of eyewitness identifications in showups and lineups

Experiment 1 tested one-person and six-person photographic lineup identifications in field situations either immediately, or 30 minutes, or 2 hours, or 24 hours after a 15-second ordinary encounter with a target. Accuracy of performance was superior in six-person lineups than in showups over time. False identifications of a lookalike innocent suspect were significantly greater in showups than in six-person lineups, especially when the suspect wore the same clothing as the culprit. Experiment 2 followed the same research design as Experiment 1, except that only live showup identifications were tested and, in addition, a physically dissimilar innocent suspect was shown to witnesses. The dissimilar innocent suspect was consistently and correctly rejected in the target-absent showup. Hit rates for live suspects were relatively low over the 24-h retention interval. Correct rejections significantly exceeded false identifications only on the immediate test. The lookalike innocent suspect was readily rejected when different clothing was worn at the test. No significant differences were found in hit scores or in confidence-accuracy scores between live and photographic targets. Confidence-accuracy correlations were significant but low across experimental conditions.     

The Effect of Lineup Member Similarity on Recognition Accuracy in Simultaneous and Sequential Lineups

Two experiments investigated whether remembering is affected by the similarity of the study face relative to the alternatives in a lineup. In simultaneous and sequential lineups, choice rates and false alarms were larger in low compared to high similarity lineups, indicating criterion placement was affected by lineup similarity structure (Experiment 1). In Experiment 2, foil choices and similarity ranking data for target present lineups were compared to responses made when the target was removed from the lineup (only the 5 foils were presented). The results indicated that although foils were selected more often in target-removed lineups in the simultaneous compared to the sequential condition, responses shifted from the target to one of the foils at equal rates across lineup procedures.     

The showup identification procedure: An exploration of systematic biases

Purpose. Showups are common, yet little research has investigated the biasing factors that may influence showup identifications. We investigated the effects of cross‐race conditions and clothing bias on showup identification decisions. Additionally, we explored identification decisions made in a subsequent lineup dependent on race, clothing, and showup‐target‐presence. Methods. Participants watched a mock crime and were presented with a showup in which suspect race, target‐presence, and the clothing worn by the suspect were varied. Following a delay, participants viewed a target‐present or ‐absent lineup and were asked to make a second identification decision. Results. Presentation of the suspect in the clothing worn by the perpetrator increased choosing rates in both own‐race and other‐race conditions. Despite this, differential patterns of decision response latencies indicated that eyewitnesses may use clothing information differently when making own‐race compared to other‐race identification decisions. No evidence for an own‐race bias in showup identifications was found; however, other‐race lineup identifications were less accurate than own‐race lineup identifications. Further, participants in own‐race and other‐race conditions differed in the extent to which they were affected by multiple identification procedures. Viewing an own‐race innocent suspect in a showup increased subsequent false lineup identifications, while choosing the innocent suspect from the showup was necessary to increase false lineup identifications in other‐race conditions. Conclusions. Different situational factors may affect the identification accuracy of eyewitnesses in own‐race and other‐race conditions for both showup and lineup procedures. Particular caution is advised when showups are clothing‐biased and multiple identification procedures are used.     

Perspectives on the impact of lineup composition,race, and witness confidence on identification accuracy

This paper addresses a number of issues suggested by the Lindsay and Wells (1980) study on lineup composition and identification accuracy. The interaction between bias in instructions to the witness, presence or absence of the criminal from the lineup, and similarity between the suspect and the lineup foils are discussed. Although Lindsay and Wells suggest that witness confidence has little or no relationship to witness accuracy, it is pointed out that a recent field study found a substantial accuracy-confidence relationship when criminal-present photo lineups were used. There are not yet clearcut findings on the accuracy-confidence relationship in criminal-absent lineups, partially because of ambiguity in the definition of confidence in this situation. Although there is much research on the impact of the race of suspect and witness on identification accuracy, little attention has been paid to the race of the person who constructs the photo or corporeal lineup. Recent research results lead to the prediction of an interaction between all three of these factors on identification accuracy, with greatest accuracy when the lineup constructor and lineup members are of the same race and the witness is of a different race. Issues in the applicability of the results of Bayesian analyses to the judicial system are briefly discussed. Potential issues include the tendency to see researchers solely as advocates for the defense, and the tendency of people to disregard statistical summaries such as base rate data and research results when making individual decisions. An additional issue concerns Bayesian diagnosticity ratios (derived from rates of correct and false identifications) which can be logically and statistically equivalent to one another but differ considerably in their legal applications and value relevance.     

The Target-to-Foils Shift in Simultaneous and Sequential Lineups

A theoretical cornerstone in eyewitness identification research is the proposition that witnesses, in making decisions from standard simultaneous lineups, make relative judgments. The present research considers two sources of support for this proposal. An experiment by G. L. Wells (1993) showed that if the target is removed from a lineup, witnesses shift their responses to pick foils, rather than rejecting the lineups, a result we will term a target-to-foils shift. Additional empirical support is provided by results from sequential lineups which typically show higher accuracy than simultaneous lineups, presumably because of a decrease in the use of relative judgments in making identification decisions. The combination of these two lines of research suggests that the target-to-foils shift should be reduced in sequential lineups relative to simultaneous lineups. Results of two experiments showed an overall advantage for sequential lineups, but also showed a target-to-foils shift equal in size for simultaneous and sequential lineups. Additional analyses indicated that the target-to-foils shift in sequential lineups was moderated in part by an order effect and was produced with (Experiment 2) or without (Experiment 1) a shift in decision criterion. This complex pattern of results suggests that more work is needed to understand the processes which underlie decisions in simultaneous and sequential lineups.     

Eyewitness identification procedures for multiple perpetrator crimes: a survey of police in Sweden,Belgium, and the Netherlands

ABSTRACT

A considerable proportion of crimes involve multiple perpetrators. Yet, little is known about how police officers construct, administer, and record eyewitness identification procedures for multiple suspects. An online survey of law enforcement agents in Sweden, Belgium, and the Netherlands (N?=?51) was conducted to obtain an initial understanding of police perceptions of prevalence and characteristics of multiple perpetrator crimes, and to examine identification procedure practices given the little to no guidance provided for police. Practice converged when it came to the use of sequential, photographic lineups, but diverged between and within countries on whether or not suspects of multiple perpetrator crimes should be placed in separate lineups. Results specifically highlight contextual cuing as one critical area for future research in identification for multiple perpetrator crimes (i.e. placing multiple suspects in the same lineup or asking eyewitnesses to look for a specific suspect).     

Probative Value of Absolute and Relative Judgments in Eyewitness Identification

It is well-accepted that eyewitness identification decisions based on relative judgments are less accurate than identification decisions based on absolute judgments. However, the theoretical foundation for this view has not been established. In this study relative and absolute judgments were compared through simulations of the WITNESS model (Clark, Appl Cogn Psychol 17:629–654, 2003) to address the question: Do suspect identifications based on absolute judgments have higher probative value than suspect identifications based on relative judgments? Simulations of the WITNESS model showed a consistent advantage for absolute judgments over relative judgments for suspect-matched lineups. However, simulations of same-foils lineups showed a complex interaction based on the accuracy of memory and the similarity relationships among lineup members.     

The Effect of Post-ID Feedback on Retrospective Self-Reports in Showups

This study examined the effects of post-identification feedback on witness retrospective self-reports in showups and lineups, and importantly, focused on guilty and innocent suspect identifications. After viewing a mock crime video, participants were asked to identify the suspect from either a target-present or target-absent photo lineup or showup. Participants were randomly assigned to receive confirming feedback (“Great job, you made the correct decision”) or no feedback about their identification, before self-reporting confidence, view, attention, willingness to testify, and trust of a witness with a similar view. We replicated the typical finding that confirming feedback inflated witness self-reports and resulted in a larger proportion of witnesses meeting the credibility threshold necessary to testify. Importantly, we also found that showups had significantly higher self-reports than lineups, despite the equal discriminability achieved in this study between these two procedures. These data provide yet another reason for the police to restrict use of showups.     

Much better than the sequential lineup: a 120-person lineup

Abstract

Large lineups may be more reliable than small ones. However, research has found greatly reduced identifications in 40-person lineups of photos shown sequentially one at a time. The task may be more difficult than necessary. Grouping photos may provide an easier one. Three studies had compared seven-page lineups (42, 84, or 168 members) with lineups of about 20. In the first two studies identification and mistaken choice rates were identical in the large and smaller lineup. Identifications in the 168-person lineup were much less. This study tested a 10-page 120-person lineup, and added a 12-person lineup. No difference was found between the 120- and 24-person lineups, and an interaction in 12-person lineups was found between graduate lab student witnesses and others. False identifications, and the probability that the suspect is innocent when ‘identified’, is much less in 120-person lineups than the 24- or 12-person lineups, or the sequential lineup.