This experiment was designed to examine the effect of misinformation imparted through cowitness discussions on memory reports and line-up decisions obtained after varied retention intervals. Two-hundred and eighty-nine participants viewed a simulated car-jacking and then heard co-witnesses describe their memory for the event. Confederate accounts included three plausible and three implausible pieces of misinformation. Memory for the event was assessed after fiveminutes, 50-minutes, two-days, or one-week. In addition to examining free-recall memory, we also looked at how misinformation about the perpetrator's appearance affected recognition memory by obtaining identifications from culprit-present and absent lineups. One of the confederates falsely described the perpetrator having a tattoo on his neck, and one lineup filler had this feature. Results revealed that mistaken identifications of the tattooed filler increased significantly at the longer retention intervals, while recall for the misinformation decreased at the longer intervals. Also, as expected, plausible misinformation was recalled more often than implausible. In the early morning hours of a summer night in Southern California, Brenda J. and her friend were coming back from a night of bar hopping and were confronted by two men who demanded her car keys. After a brief struggle, one of the assailants took her purse and fled. The police interviewed the witnesses separately. Brenda recalled that the assailant had some type of undefined tattoos on his face, but her friend remembered him having the letters tattooed on his head. In the days after the event, the two friends talked more about the shared experience, and searched social media together, looking for pictures of tattoos similar to what they remembered. After reviewing dozens of pictures together, the two women arrived at the shared conclusion that the culprit had letters tattooed on his face (a merging of the two witnesses' memory reports), and the women believed they may have even found a picture of the culprit. The witnesses then went back to the police with this new information, and the police immediately developed a suspect named Richard Torres who had letters tattooed on his face, similar to what the victims reported. The police then put Torres' picture in a sequential line-up with five other individuals, none of whom had tattoos on their face, and administered it to both witnesses using double-blind procedures. Not surprisingly, both witnesses picked Torres from the line-up, and each noted the importance of the letter tattoos in making their decision (People v. Richard Torres, San Diego Superior Court; February, 2015, CD256364). Surveys of real eyewitnesses to crimes reveal that co-witnesses like Brenda J. and her friend frequently talk together about their shared experiences (Paterson & Kemp, 2006; Skagerberg & Wright, 2008). Moreover, because witnesses' descriptions of perpetrators tend to vary after a crime (Gabbert & Brown, 2015), it is reasonable to assume that witnesses who participate in...

When following scientific best-practice recommendations, the simultaneous lineup is effective at demonstrating guilt. The simultaneous lineup is less effective at demonstrating innocence. A critical problem is that when a witness identifies a filler or indicates the culprit is not present, confidence does not measure the strength of match between the suspect and the witness's memory for the culprit. We propose a novel rule-out procedure as a potential remedy. After making an identification decision and expressing their confidence, participants indicated for each person they did not identify, how confident they were this person was not the culprit. The rule-out procedure better discriminated guilty suspects from innocent suspects than did the simultaneous lineup. This improvement was strictly attributable to increased potential to rule out the innocent. Interestingly, both witnesses who made rejections and witnesses who mistakenly identified fillers possessed additional memorial information that was useful for ruling out the innocent.

Objective: This field-simulation experiment was designed to compare eyewitness performance when conducting show ups and lineups under field versus laboratory conditions. Hypotheses: We expected to replicate the findings from previous field-simulation experiments showing overconfidence in show up identifications made under field but not lab conditions, and further predicted that under field conditions, high-confidence identifications are more likely to be correct when using lineups compared with show ups. It was also expected that field conditions would lead witnesses to lower their criterion for choosing with show ups, but we did not know how field conditions would affect lineup decision-making. Method: Participants (N = 719) witnessed the theft of a laptop computer and were asked to identify a suspect from a live show up, a photographic show up, or a photographic lineup administered under either field or lab conditions. In the field condition, uniformed officers functioned as experimenters and participants were immersed in what they were led to believe was an actual police investigation. In the lab condition, participants were debriefed before the identification procedure that the theft was staged for research purposes and that their identifications were being made as part of a study on eyewitness memory. Results: As predicted, witnesses were overconfident in their show up identifications made under field but not lab conditions, and high-confidence identifications were more likely to be correct when using lineups compared with show ups. Also as expected, field conditions led witnesses to lower their criterion for choosing with show ups regardless of culprit presence. However, the opposite was true for lineups, such that field conditions resulted in witnesses raising their criterion for choosing. Conclusions: Field conditions had a very different effect on witness performance when conducting show ups compared with lineups. When witnesses were led to believe that their identification would result in the arrest and prosecution of the suspect, they became more liberal in their decision-making when show ups were used but more conservative when lineups were employed. Public Significance StatementThis study examined how real-world conditions affect eyewitnesses beyond what can be assessed in a lab study. This was accomplished by comparing eyewitnesses' performance when they knew they were participating in research to their performance under field conditions, in which their identification would presumably result in the arrest of the suspect. Results demonstrated that many important findings from previous lab studies generalized well to field conditions, but also revealed that the situational pressures of being a witness in an actual police investigation can affect eyewitness performance differently depending on the procedures used to obtain the identification.

Visual recognition memory has a remarkable capacity to discriminate between previously seen and novel items. Yet, research on eyewitness lineups suggests that memory is useful for detecting culprit presence, but less useful for detecting culprit absence. We show that this asymmetry is predicted by the equal-variance signal-detection model. When witnesses reject lineups, they provide a global confidence rating that none of the lineup members is the culprit. These ratings do not scale match-to-memory for the suspect and are low in diagnostic value. Consequently, the equal-variance signal-detection model predicts that a one-person showup will have better discriminability than a six-person lineup. A largescale experiment (N = 3281) supported that prediction. However, a modified lineup in which participants were asked to follow categorical identification decisions by assigning a confidence rating to each lineup member had better discriminability than both the showup and the standard simultaneous lineup. We call this modified lineup the rule out procedure. Results also revealed a relatively weak confidenceaccuracy relation for global rejections of lineups, but a much stronger confidence-accuracy relation for rejections of individual faces. Past failures to detect suspect innocence with lineups should be attributed to flawed design, not to limitations of visual recognition memory.

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