The purpose of this research is to conduct both a lab and field study to examine the relationships between 1) confidence and accuracy, and 2) response latency and accuracy in show-up identifications, as well as to 3) examine current practices of law enforcement agencies in eyewitness procedures, especially those related to show-ups.
Eyewitnesses’ confidence in their identifications in photo arrays or lineups was once believed unrelated to the accuracy of the IDs, however, recent evidence has reversed that view. Laboratory research has recently established a strong confidence-accuracy relationship for lineup tests (Wixted & Wells, 2017). This research indicates IDs made with high confidence—during the initial viewing/identification—are likely to be correct whereas IDs made with low confidence signal a sometimes-substantial chance that the identification may be of an innocent person. This evidence also appears to hold in real-crime settings based on the results of a field study conducted in Houston (W. Wells, 2014; Wixted, Mickes, Dunn, Clark, & W. Wells, 2016).
The mounting evidence on the important relationship between confidence and accuracy subsequently led the International Association of Chiefs of Police (IACP), the National Academy of Sciences, and the U.S. Department of Justice to issue guidelines and/or make recommendations that law enforcement record initial confidence of witnesses in identification procedures as a matter of policy (IACP, 2016; NRC, 2014; Yates memo, DOJ, 2017). However, while confidence has been demonstrated to be a strong predictor of accuracy in identifications made from photo arrays, far less is known about the relationship of confidence and accuracy in field show-up procedures.
A “show-up” is an eyewitness identification procedure that takes place shortly after a crime has occurred when the police have found a description-matched suspect and the witness or victim is driven to a location where the detained suspect is located to make an identification (usually close in proximity and time to the crime, see Behrman & Davey, 2001). Show-ups are typically conducted in the field (usually from the back seat of a police vehicle where the witness/victim cannot be seen by the suspect) in order to allow an eyewitness to evaluate whether or not that detained person is the perpetrator. Examining the confidence-accuracy relationship for field show-ups is important because field show-ups are a common form of eyewitness practice reportedly used in 30 to 77 percent of identification cases (Dysart & Lindsay, 2007; Gonzalez, Ellsworth, & Pembroke, 1993; Steblay, Dysart, Fulero, & Lindsay, 2003). The last national survey of eyewitness identification practices found that show-ups are conducted in over 60 percent of agencies (PERF, 2013).
Despite their frequency of use, show-ups have been deemed by many in the criminal justice system to be too suggestive and therefore, the confidence expressed in a show-up identification is likely underutilized. Because of these concerns, current IACP policy recommends avoiding show-ups when photo arrays could be used instead (IACP 2016). It is clear that some agencies have indeed abandoned the use of show-ups altogether, though the extent to which agencies in the U.S. use or don’t use them to identify suspects is currently unknown. Furthermore, the conclusion that show-ups are too suggestive may be premature; show-ups may in fact have significant utility in identifying the suspects shortly after a crime is committed (which is likely why many agencies still use them), provided their reliability can be maximized and suggestiveness of the procedure reduced.
Although field research has not yet examined the confidence-accuracy relationship in live show-ups, laboratory-based data suggest this relationship may be less indicative of accuracy, with some demonstrating that confidence in those identifications is inflated (Eisen, Smith, Olaguez, & Skerritt-Perta, 2017). It is not clear what may account for a weaker relationship between confidence and accuracy in show-ups versus photo arrays, but some have posited it is due to an inability to make comparisons across facial features that reduces this relationship (Wixted & Mickes, 2014). Notably, as well, the studies to date have relied primarily on images of suspects rather than live in-person suspects as in real show-up procedures. These studies have shown that high confidence IDs from photo show-ups are lower than expected (Mickes, 2015; Wetmore et al., 2015). However, in a recent lab-based pilot experiment with live show-ups (using actors), confidence in a show-up decision was in fact, informative of accuracy (Seale-Carlisle & Mickes, 2018). The findings to date are far from conclusive and have yet to be tested more systematically in the field. A key takeaway is that there is too little data on the important issue involving the confidence-accuracy relationship in field show-ups and related procedures that can be employed to make these identifications more reliable.
In addition, evidence has routinely demonstrated that the time it takes a witness to identify a suspect (also known as latency) is probative; the faster those decisions are, the more likely they are to reflect ground truth (see e.g., Sauerland, Sagana, & Sporer, 2012; Sauerland & Sporer, 2009). Information about eyewitness latency of decisions in show-ups from the field has the potential to shed light on the extent to which it is predictive of accuracy in these circumstances, as well as help to identify ways to make field show-ups more reliable.
Given the frequency of show-up procedures in the field and experts’ assessments that this practice is “likely to continue” (Neuschatz et al., 2016, p. 66), these questions about confidence, latency, and their relationships to accuracy are of paramount importance. This is especially the case because some courts have begun to raise questions about their reliability and admissibility. Further, eyewitness science has moved apace in the past five to eight years resulting in a substantial upending of prior research and consensus in the eyewitness identification field (Gronlund & Benjamin, 2018). Hence, it is necessary to gather updated knowledge about current law enforcement agencies’ policies and practices, specifically with regard to field show-ups. Finally, if confidence and latency are predictive of eyewitness accuracy in field show-ups, the evidence arising from this project could establish the probative nature of confidence statements and latency and help to strengthen cases against guilty suspects while reducing the likelihood of wrongful convictions of innocent persons.
Study 1: Laboratory based experiment. In the lab experiment we will use video based vignettes of mock crimes. After viewing the vignettes, participants will be asked to solve puzzles for 15 minutes (a distractor phase). The participants will return to test their memory of the perpetrator as a show-up witness, and we will test both confidence and latency (time to make a decision). Because the actual perpetrator is known in these scenarios we will be able to test for accuracy of identifications.
Study 2: Field study. In the field study, we will collect information from agencies on show-ups they conduct including their confidence and latency. Because actual perpetrators are unknown, we will rely on a proxy of ground truth, ratings of evidentiary strength using a previously developed rating scale (Amendola & Slipka, 2009). This will be used to determine accuracy of the identifications.
Study 3: Nationwide survey. As a follow-on to the PERF survey conducted in 2011 (published in 2013), we will be assessing changes over time in policies, practices, and knowledge of scientific evidence as it has advanced rapidly over the past decade. We will focus on photographic arrays and show-ups as these are most commonly used, while avoiding questions related to mug shots, live lineups, and composite sketches (although PERF did include those). By focusing solely on show-ups and photo arrays will allow us to ask more in-depth questions. We hope to describe field practices, policies and knowledge and examine differences over time.
Not yet available.
Strategic Priority Area(s)
Project Status: Active
Project Period: January 2021 -
Research Design: Randomized controlled trial (RCT), Non-experimental
Research Method(s): Field-based experiment, Lab-based experiment, Surveys
Strategic Priority Area(s)