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.     

A method for increasing empirical discriminability and eliminating top‐row preference in photo arrays

It is important to consider the two parameters of signal detection theory, discriminability and response bias, when evaluating eyewitness identification from simultaneous lineups. On the basis of the diagnostic feature‐detection hypothesis, we tested a method for increasing discriminability that encourages eyewitnesses to carefully rank each lineup member based on match to their memory for a perpetrator. This procedure increased empirical discriminability and also eliminated a response bias that is largely overlooked in the literature: Participants were biased to choose from the top row of the six‐pack (2 × 3) lineup commonly used in the United States. We argue that suspect position in the simultaneous lineup is an important variable to consider for researchers and the criminal justice system. We also encourage researchers to test the ranking procedure to determine if such a simple set of instructions could be utilized by police to help eyewitnesses correctly sort innocent versus guilty suspects.     

Double Exposure: The Effects of Repeated Identification Lineups on Eyewitness Accuracy

Eyewitnesses may be asked to identify the same suspect from a lineup on successive occasions. This study explored the effects on eyewitness decisions of repeated same‐suspect lineups, within a 2 × 2 × 2 mixed‐model factorial design. Witnesses to a video crime attempted to identify the culprit from two same‐format lineups (simultaneous or sequential) separated by a 2‐week retention interval (Lineup1, Lineup2) in which a suspect (guilty or innocent) was common to the lineups. We predicted two components of a posited repeated lineup effect: that positive identification errors made at the first lineup would be carried forward rather than corrected at the second lineup and that the number of false identifications of the innocent suspect would rise from first to second lineup. Predictions were supported, with a stronger negative impact of repeated lineups for simultaneous than sequential lineups. Additionally, witnesses who made selections of the guilty suspect and of the innocent suspect at Lineup2 were equally confident and were significantly more confident than witnesses who declined to pick. The results underscore concerns about possible negative outcomes from repeated lineups. Copyright © 2013 John Wiley & Sons, Ltd.     

Enhancing lineup identification accuracy: two codes are better than one

Ways of improving identification accuracy were explored by comparing the conventional visual lineup with an auditory/visual lineup, one that paired color photographs with voice recordings. This bimodal lineup necessitated sequential presentation of lineup members; Experiment 1 showed that performance in sequential lineups was better than performance in traditional simultaneous lineups. In Experiments 2A and 2B unimodal and bimodal lineups were compared by using a multiple-lineup paradigm: Ss viewed 3 videotaped episodes depicting standard police procedures and were tested in 4 sequential lineups. Bimodal lineups were more diagnostic than either visual or auditory lineups alone. The bimodal lineup led to a 126% improvement in number of correct identifications over the conventional visual lineup, with no concomitant increase in number of false identifications. These results imply strongly that bimodal procedures should be adopted in real-world lineups. The nature of memorial processes underlying this bimodal advantage is discussed.     

Lineup composition, suspect position, and the sequential lineup advantage

N. M. Steblay, J. Dysart, S. Fulero, and R. C. L. Lindsay (2001) argued that sequential lineups reduce the likelihood of mistaken eyewitness identification. Experiment 1 replicated the design of R. C. L. Lindsay and G. L. Wells (1985), the first study to show the sequential lineup advantage. However, the innocent suspect was chosen at a lower rate in the simultaneous lineup, and no sequential lineup advantage was found. This led the authors to hypothesize that protection from a sequential lineup might emerge only when an innocent suspect stands out from the other lineup members. In Experiment 2, participants viewed a simultaneous or sequential lineup with either the guilty suspect or 1 of 3 innocent suspects. Lineup fairness was varied to influence the degree to which a suspect stood out. A sequential lineup advantage was found only for the unfair lineups. Additional analyses of suspect position in the sequential lineups showed an increase in the diagnosticity of suspect identifications as the suspect was placed later in the sequential lineup. These results suggest that the sequential lineup advantage is dependent on lineup composition and suspect position.     

The Effect of Backloading Instructions on Eyewitness Identification from Simultaneous and Sequential Lineups

The sequential lineup is multifaceted, including serial presentation of faces, multiple decisions, and often backloading (indicating to an eyewitness that a lineup contains more photos than there actually are). We evaluated the effect of backloading instructions on response bias and sensitivity with an eyewitness identification paradigm. Importantly, we included an ‘undisclosed’ condition that provided no information to participants about the number of lineup members to expect. Experiment 1 (N = 780) tested sequential lineups; Experiment 2 (N = 532) tested simultaneous lineups. As predicted, signal detection analysis showed that backloading induced participants to be more conservative in choosing from both lineup types, but did not affect d′. We conclude that the criminal justice system should be mindful of this shift in response bias, as it has implications for both guilty and innocent suspect identifications. Copyright © 2016 John Wiley & Sons, Ltd.     

An exploration of visual behaviour in eyewitness identification tests

The contribution of internal (eyes, nose and mouth) and external (hair‐line, cheek and jaw‐line) features across eyewitness identification tests was examined using eye tracking. In Experiment 1 , participants studied faces and were tested with lineups, either simultaneous (test faces presented in an array) or sequential (test faces presented one at a time). In Experiment 2, the recognition of previously studied faces was tested in a showup (a suspect face alone was presented). Results indicated that foils were analysed for a shorter period of time in the simultaneous compared to the sequential condition, whereas a positively identified face was analysed for a comparable period of time across lineup procedures. In simultaneous lineups and showups, a greater proportion of time was spent analysing internal features of the test faces compared to sequential lineups. Different decision processes across eyewitness identification tests are inferred based on the results. Copyright © 2010 John Wiley & Sons, Ltd.     

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.     

Eyewitness identification in simultaneous and sequential lineups: an investigation of position effects using receiver operating characteristics

For decades, sequential lineups have been considered superior to simultaneous lineups in the context of eyewitness identification. However, most of the research leading to this conclusion was based on the analysis of diagnosticity ratios that do not control for the respondent’s response criterion. Recent research based on the analysis of ROC curves has found either equal discriminability for sequential and simultaneous lineups, or higher discriminability for simultaneous lineups. Some evidence for potential position effects and for criterion shifts in sequential lineups has also been reported. Using ROC curve analysis, we investigated the effects of the suspect’s position on discriminability and response criteria in both simultaneous and sequential lineups. We found that sequential lineups suffered from an unwanted position effect. Respondents employed a strict criterion for the earliest lineup positions, and shifted to a more liberal criterion for later positions. No position effects and no criterion shifts were observed in simultaneous lineups. This result suggests that sequential lineups are not superior to simultaneous lineups, and may give rise to unwanted position effects that have to be considered when conducting police lineups.     

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.     

Protecting innocent defendants,nailing the guilty: a modified sequential lineup

Can the traditional lineup procedure be modified in such a way as to still secure positive identifications of guilty persons while minimizing the risk of misidentifications? Witnesses interacted with a ‘culprit’ who they were later called upon to identify from a 20-person sequential video lineup. Both culprit-present and culprit-absent lineups were employed and witnesses could choose more than one suspect. In 61 culprit-present lineups 43% chose only the suspect, while in 93 culprit-absent lineups no-one did. In culprit-present lineups 25% chose him along with foils, while 5% did so in culprit-absent lineups. Larger lineup size, and the ability to make multiple choices, helped lower the probability of choosing only an innocent suspect. Using Baysian analysis, the probability that a chosen defendant was innocent, based on the lineup alone, equalled 0.03, compared to 0.258 in traditional lineups. © 1998 John Wiley & Sons, Ltd.     

Configural and component processing in simultaneous and sequential lineup procedures

Configural processing supports accurate face recognition, yet it has never been examined within the context of criminal identification lineups. We tested, using the inversion paradigm, the role of configural processing in lineups. Recent research has found that face discrimination accuracy in lineups is better in a simultaneous compared to a sequential lineup procedure. Therefore, we compared configural processing in simultaneous and sequential lineups to examine whether there are differences. We had participants view a crime video, and then they attempted to identify the perpetrator from a simultaneous or sequential lineup. The test faces were presented either upright or inverted, as previous research has shown that inverting test faces disrupts configural processing. The size of the inversion effect for faces was the same across lineup procedures, indicating that configural processing underlies face recognition in both procedures. Discrimination accuracy was comparable across lineup procedures in both the upright and inversion condition. Theoretical implications of the results are discussed.     

The not‐sure response option in sequential lineup practice

Field implementation of double‐blind sequential lineups has prompted a question about the impact on eyewitness decisions of an explicit not‐sure response option. In this laboratory study, a video crime was viewed by 378 participants who then attempted to identify the culprit from a six‐person sequential or simultaneous‐format lineup that either included or did not include the culprit. Witnesses were provided either dichotomous forced‐choice (FC) response categories (yes/no) or a not‐sure option as one of three response categories (yes/no/not‐sure). The not‐sure option (NSO) significantly decreased witness choosing compared to the FC condition but only for sequential lineups. Both correct identifications and false alarms decreased. Diagnosticity was greatest for a sequential lineup with a NSO. The results suggest a criterion decision shift for witnesses who view a sequential lineup with a not‐sure response option. Copyright © 2010 John Wiley & Sons, Ltd.     

Asking an eyewitness to predict their later lineup performance could harm the confidence–accuracy relationship

Few studies have investigated eyewitnesses' ability to predict their later lineup performance, known as predecision confidence. We applied calibration analysis in two experiments comparing predecision confidence (immediately after encoding but prior to a lineup) to postdecision confidence (immediately after a lineup) to determine which produces a superior relationship with lineup decision accuracy. Experiment 1 (N = 177) featured a multiple-block lineup recognition paradigm featuring several targets and lineups; Experiment 2 featured an eyewitness identification paradigm with a mock-crime video and a single lineup for each participant (N = 855). Across both experiments, postdecision confidence discriminated well between correct and incorrect lineup decisions, but predecision confidence was a poor predictor of accuracy. Moreover, simply asking for predecision confidence weakened the postdecision confidence–accuracy relationship. This implies that police should exercise caution when interviewing eyewitnesses, as they should not be asked to predict their ability to make an accurate lineup decision.     

Biased lineups: sequential presentation reduces the problem.

Biased lineups have been shown to increase significantly false, but not correct, identification rates (Lindsay, Wallbridge, & Drennan, 1987; Lindsay & Wells, 1980; Malpass & Devine, 1981). Lindsay and Wells (1985) found that sequential lineup presentation reduced false identification rates, presumably by reducing reliance on relative judgment processes. Five staged-crime experiments were conducted to examine the effect of lineup biases and sequential presentation on eyewitness recognition accuracy. Sequential lineup presentation significantly reduced false identification rates from fair lineups as well as from lineups biased with regard to foil similarity, instructions, or witness attire, and from lineups biased in all of these ways. The results support recommendations that police present lineups sequentially.     

An evaluation of lineup presentation,weapon presence,and a distinctive feature using ROC analysis

We conducted an experiment (N = 2675) including both laboratory and online participants to test hypotheses regarding important system and estimator variables for eyewitness identification. Simultaneous lineups were compared to sequential lineups with the suspect presented early versus late because there is evidence that suspect position could be an important factor determining a simultaneous versus sequential advantage in guilty-innocent suspect discriminability. We also manipulated whether or not the perpetrator held a weapon or had a distinctive feature on his face, to re-evaluate recent evidence that these factors interact. Overall, the simultaneous lineup yielded higher discriminability than the sequential lineup, and there was no effect of sequential position. Discriminability was higher when the perpetrator had no weapon, but only when no distinctive feature was present. We conclude with a discussion of the importance of exploring interactions between system and estimator variables using Receiver Operating Characteristic (ROC) analysis.     

The impact of evidence lineups on fingerprint expert decisions

Forensic examiners routinely compare a crime-relevant mark of unknown origin against a single suspect's sample, which may create an expectation that the two will match. We tested how embedding the suspect's sample among known-innocent fillers (i.e., an evidence lineup) affects expert decision-making. Experienced fingerprint examiners (N = 43) compared crime-relevant marks against either individual suspect fingerprints (i.e., the standard procedure) or arrays of fingerprints (i.e., evidence lineups), with a matching fingerprint either present or absent. Evidence lineups promoted conservative decision-making, as evidenced by fewer correct IDs and a higher rate of inconclusive judgments. Though errors were rare, evidence lineups also occasionally revealed errors that would have otherwise gone undetected. Our findings thus support arguments that evidence lineups can expose fraud, identify flawed methodologies, and curb overconfidence. The potential benefits and challenges of implementing evidence lineups in forensic laboratories are discussed.