Showups versus lineups: An evaluation using ROC analysis

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.     

The confidence-accuracy relationship in eyewitness identification: effects of lineup instructions, foil similarity, and target-absent base rates

Discriminating accurate from mistaken eyewitness identifications is a major issue facing criminal justice systems. This study examined whether eyewitness confidence assists such decisions under a variety of conditions using a confidence-accuracy (CA) calibration approach. Participants (N = 1,200) viewed a simulated crime and attempted 2 separate identifications from 8-person target-present or target-absent lineups. Confidence and accuracy were calibrated for choosers (but not nonchoosers) for both targets under all conditions. Lower overconfidence was associated with higher diagnosticity, lower target-absent base rates, and shorter identification latencies. Although researchers agree that courtroom expressions of confidence are uninformative, our findings indicate that confidence assessments obtained immediately after a positive identification can provide a useful guide for investigators about the likely accuracy of an identification.     

Why Do Eyewitnesses Make So Many Mistakes?

Previous research on eyewitness identification has demonstrated high rates of error. Subjects have frequently identified innocent targets as the "criminal" they had seen earlier (false identifications) or had falsely claimed that the criminal was not in the line-up (misses). The present study examines whether identification error rates are inflated by pressures in the typical experimental situation to "make a guess" regardless of one's confidence in the accuracy of the response. It was found that providing an explicit option for subjects to respond "don't know" significantly decreased false identifications and misses with no cost to the proportion of correct identifications. The addition of written and verbal instructions emphasizing the acceptability of the "don't know" option produced a marginally significant further decline in identification errors, again without cost to correct identifications. The discussion considered implications of the present results for experimental and actual police line-up procedures.     

Crime Type,Perceived Stereotypicality,and Memory Biases: A Contextual Model of Eyewitness Identification

The fallibility of eyewitness identifications is well documented. Nevertheless, research has yet to assess the possibility that the type of crime committed systematically influences who eyewitnesses mistakenly identify. We address this oversight by presenting a contextual model of eyewitness identification (CMEI). The CMEI asserts that discrete crimes automatically activate distinct stereotypes about a perpetrator's appearance. Depending on the congruence between these stereotypes and the perpetrator's actual appearance, eyewitnesses will remember the perpetrator as appearing more (or less) representative of his or her group (i.e., higher or lower on perceived stereotypicality). Estimator and system variables are posited to affect identifications at different stages of the identification process. The literatures on stereotype activation, perceived stereotypicality, and stereotype‐consistent memory biases are reviewed to support the CMEI. Our conceptual integration provides a model of eyewitness identification that explains when mistaken identifications are likely to occur and who they are likely to affect. Copyright © 2014 John Wiley & Sons, Ltd.     

The Effects of Discussion on Eyewitness Memory1

This study investigated the effects of witness discussion on the accuracy of recall and misidentifications in eyewitness memory. Dyadic groups who discussed the crime and dyads who made joint memorial decisions about the incident were more accurate in recall than were dyads who discussed noncriminal matters, and a no-discussion group. Collaborative dyads giving joint decisions also were significantly more accurate than were the other groups in rejection of the culprit-absent lineup. The sequential lineup method proved superior to the simultaneous method, regardless of whether or not witnesses discussed the crime prior to identification. It was concluded that discussion and joint decision making by 2 eyewitnesses can improve both eyewitness recall and minimize false identifications in some circumstances.     

Juror Underutilization of Eyewitness Nonidentifications: A Test of the Disconfirmed Expectancy Explanation1

The impact of two types of eyewitness testimony on mock jurors' judgments was explored. A crime eyewitness either testified that the defendant definitely was the robber (identification), definitely was not the robber (nonidentification), or that they weren't sure if he was or was not the robber (control). An alibi eyewitness testified that the defendant either definitely was at the alibi location (identification), definitely was not at the alibi location (nonidentification), or he wasn't sure if the defendant was or was not at the alibi location (control). Strength of case was also manipulated. Results show that crime eyewitness identifications and alibi eyewitness nonidentifications were underutilized. A crime eyewitness by alibi eyewitness interaction revealed that within the crime eyewitness identification condition alibi identification was underutilized whereas with the other two crime eyewitness conditions, alibi nonidentification information was underutilized. The results supported a disconfirmed expectancy explanation.     

Effects of postidentification feedback on eyewitness identification and nonidentification confidence

Two experiments investigated new dimensions of the effect of confirming feedback on eyewitness identification confidence using target-absent and target-present lineups and (previously unused) unbiased witness instructions (i.e., "offender not present" option highlighted). In Experiment 1, participants viewed a crime video and were later asked to try to identify the thief from an 8-person target-absent photo array. Feedback inflated witness confidence for both mistaken identifications and correct lineup rejections. With target-present lineups in Experiment 2, feedback inflated confidence for correct and mistaken identifications and lineup rejections. Although feedback had no influence on the confidence-accuracy correlation, it produced clear overconfidence. Confidence inflation varied with the confidence measure reference point (i.e., retrospective vs. current confidence) and identification response latency.     

Presence of administrators differentially impacts eyewitness discriminability for same- and other-race identifications

Best practice guidelines recommend that eyewitness lineup administrators be blind to a suspect's identity, but no research has investigated whether the mere presence of a lineup administrator impacts eyewitness identification decisions. Informed by social facilitation theory, we predicted that the presence of an audience would differentially impact identification accuracy for same- and other-race identifications. Participants (N = 191) viewed same- and other-race lineups either with an audience or alone. Although the presence of an audience did not directly impact identification accuracy, significant indirect effects indicated that the audience provoked evaluation apprehension which hindered other-race identification accuracy and improved same-race identification accuracy. We suggest that using double-blind lineup procedures may not sufficiently protect eyewitness identification accuracy when making other-race lineup decisions in the presence of others.     

Individual differences in face identification postdict eyewitness accuracy

Eyewitnesses frequently mistake innocent suspects for the culprits of an observed crime, and such misidentifications have caused the wrongful convictions of many innocent people. This study attempted to establish the accuracy of individual eyewitnesses by assessing their ability to process unfamiliar faces. Observers viewed a staged crime and later tried to select the culprit from an identity lineup. This was followed by a face test that provides a laboratory analogue to lineup identifications. We found that this face test could determine the reliability of individual witnesses when a positive eyewitness identification had been made. Importantly, this was possible based on the specific response that a witness had made and without prior knowledge of whether the culprit was actually present in the lineup. These findings demonstrate that individual differences in face processing provide a potential instrument for postdicting eyewitness accuracy and for preventing miscarriages of justice.     

Effects of administrator-witness contact on eyewitness identification accuracy

Concern that lineup administrators can influence eyewitness identifications has led researchers to suggest implementing double-blind testing, an idea that police resist. Using a typical eyewitness paradigm (video event followed by photographic identification test), the present study demonstrated that an alternative technique, minimizing the level of contact between lineup administrators and witnesses, could reduce false identifications without reducing hits. Specifically, witnesses were more likely to make decisions consistent with lineup administrator expectations when the level of contact between the administrator and the witness was high than when it was low. These results are explained within the experimenter expectancy framework. Implications for applied settings are discussed.     

Confessions that corrupt: evidence from the DNA exoneration case files

Basic psychology research suggests the possibility that confessions-a potent form of incrimination-may taint other evidence, thereby creating an appearance of corroboration. To determine if this laboratory-based phenomenon is supported in the high-stakes world of actual cases, we conducted an archival analysis of DNA exoneration cases from the Innocence Project case files. Results were consistent with the corruption hypothesis: Multiple evidence errors were significantly more likely to exist in false-confession cases than in eyewitness cases; in order of frequency, false confessions were accompanied by invalid or improper forensic science, eyewitness identifications, and snitches and informants; and in cases containing multiple errors, confessions were most likely to have been obtained first. We believe that these findings underestimate the problem and have important implications for the law concerning pretrial corroboration requirements and the principle of "harmless error" on appeal.     

The effect of viewing distance on empirical discriminability and the confidence–accuracy relationship for eyewitness identification

The distance from which an eyewitness views a perpetrator is a critical factor for eyewitness identification, but has received little research attention. We presented three mock-crime videos to participants, varying distance to three perpetrators (3, 10, or 20 m). Across two experiments, increased distance reduced empirical discriminability in the form of a mirror effect, such that correct identifications decreased while false identifications increased. Moreover, high confidence identifications were associated with high accuracy at 3 m (Experiment 1 and 2) and 10 m (Experiment 2), but not at 20 m. We conclude that eyewitnesses may be less likely to identify a perpetrator viewed at a distance, and also more likely to falsely identify an innocent suspect. Furthermore, there may be certain boundary conditions associated with distance and the impact it has on the confidence–accuracy relationship. More research is needed to elucidate the effect of estimator variable manipulations on the confidence–accuracy relationship.     

The Psychology of Lineup Identifications1

A review is made of issues and data on eyewitness identifications, and a relative-judgment conceptualization is proposed. It is argued that eyewitnesses are prone to choose the lineup member who most resembles the perpetrator relative to other lineup members as evidenced by studies that manipulated similarity of lineup members. The relative-judgment strategy is fallacious because of the unpredictable occurrence of target-absent lineups and is not corrected fully by instructions to eyewitnesses. An extension of the relative-judgment conceptualization proposes an inverse relationship between the goodness of witnesses' memories (quality and quantity of relevant information available in memory) and witnesses' tendencies to rely on relative judgments. This extended conceptualization was used to derive expectations regarding an experiment (N= 192 eyewitnesses) that used a blank lineup prior to presenting eyewitnesses with the actual lineup. The data indicated that a blank lineup can yield a diagnostic split of eyewitnesses; those who made no identification when presented with a blank lineup were less likely to make false identifications on the actual lineup than either the witnesses who identified someone from the blank lineup or the witnesses who were not presented with a blank lineup. The blank lineup did not produce a significant loss in accurate identifications. The practical implications of using blank lineups and the theoretical utility of the relative-judgment conceptualization are discussed.     

Are multiple-trial experiments appropriate for eyewitness identification studies? Accuracy,choosing, and confidence across trials

Eyewitness identification experiments typically involve a single trial: A participant views an event and subsequently makes a lineup decision. As compared to this single-trial paradigm, multiple-trial designs are more efficient, but significantly reduce ecological validity and may affect the strategies that participants use to make lineup decisions. We examined the effects of a number of forensically relevant variables (i.e., memory strength, type of disguise, degree of disguise, and lineup type) on eyewitness accuracy, choosing, and confidence across 12 target-present and 12 target-absent lineup trials (N?=?349; 8,376 lineup decisions). The rates of correct rejections and choosing (across both target-present and target-absent lineups) did not vary across the 24 trials, as reflected by main effects or interactions with trial number. Trial number had a significant but trivial quadratic effect on correct identifications (OR?=?0.99) and interacted significantly, but again trivially, with disguise type (OR?=?1.00). Trial number did not significantly influence participants’ confidence in correct identifications, confidence in correct rejections, or confidence in target-absent selections. Thus, multiple-trial designs appear to have minimal effects on eyewitness accuracy, choosing, and confidence. Researchers should thus consider using multiple-trial designs for conducting eyewitness identification experiments.     

Anger in lineup identification and creation

As an approach-oriented emotion, anger appears to affect behavioral thresholds in a range of contexts. The current work consists of three experiments examining this in the context of eyewitness identification procedures. Experiments 1 and 2 examined the relationship between a witness' anger and identification reliability, and Experiment 3 examined the relationship between a lineup creator's anger and the quality of selected lineup fillers. Experiments 1 and 2 showed that anger during an identification procedure is associated with increased risk of false identifications and reduced confidence-accuracy calibration. Experiment 3 showed that anger is associated with lower quality of fillers selected by lineup creators. Together, these experiments suggest that anger may undermine the quality of eyewitness evidence, even when the witnesses themselves are not the ones experiencing anger and even when anger is not directed at the perpetrator or suspect.     

Eyewitness identification accuracy and response latency: the unruly 10-12-second rule

Data are reported from 3,213 research eyewitnesses confirming that accurate eyewitness identifications from lineups are made faster than are inaccurate identifications. However, consistent with predictions from the recognition and search literatures, the authors did not find support for the "10-12-s rule" in which lineup identifications faster than 10-12 s maximally discriminate between accurate and inaccurate identifications (D. Dunning & S. Perretta, 2002). Instead, the time frame that proved most discriminating was highly variable across experiments, ranging from 5 s to 29 s, and the maximally discriminating time was often unimpressive in its ability to sort accurate from inaccurate identifications. The authors suggest several factors that are likely to moderate the 10-12-s rule.     

PC_Eyewitness: Evaluating the New Jersey method

One important variable in eyewitness identification research is lineup administration procedure. Lineups administered sequentially (one at a time) have been shown to reduce the number of false identifications in comparison with those administered simultaneously (all at once). As a result, some policymakers have adopted sequential administration. However, they have made slight changes to the method used in psychology laboratories. Eyewitnesses in the field are allowed to take multiple passes through a lineup, whereas participants in the laboratory are allowed only one pass. PC_Eyewitness (PCE) is a computerized system used to construct and administer simultaneous or sequential lineups in both the laboratory and the field. It is currently being used in laboratories investigating eyewitness identification in the United States, Canada, and abroad. A modified version of PCE is also being developed for a local police department. We developed a new module for PCE, the New Jersey module, to examine the effects of a second pass. We found that the sequential advantage was eliminated when the participants were allowed to view the lineup a second time. The New Jersey module, and steps we are taking to improve on the module, are presented here and are being made available to the research and law enforcement communities.     

Identifying the Culprit: An International Perspective on the National Academy of Sciences Report on Eyewitness Identification Evidence

The recent National Research Council report on eyewitness identification evidence includes fifteen recommendations intended to improve the procedures used to obtain eyewitness identification evidence, strengthen its value in court, and improve the scientific basis of research. The report includes some important insights on the applied research and makes some novels proposals, which are critically reviewed. It is argued that the report is limited by a lack of international comparison and by its focus exclusively on lineups rather than a wider range of methods available to identify perpetrators from their face.