Backloading in the sequential lineup prevents within-lineup criterion shifts that undermine eyewitness identification performance.

Abstract

Although the sequential lineup has been proposed as a means of protecting innocent suspects from mistaken identification, little is known about the importance of various aspects of the procedure. One potentially important detail is that witnesses should not know how many people are in the lineup. This is sometimes achieved by backloading the lineup so that witnesses believe that the lineup includes more photographs than it actually does. This study aimed to investigate the effect of backloading on witness decision making. A large sample (N = 833) of community-dwelling adults viewed a live "culprit" and then saw a target-present or target-absent sequential lineup. All lineups included 6 individuals, but the participants were told that the lineup included 6 photographs (nonbackloaded condition) or that the lineup included 12 or 30 photographs (backloaded conditions). The suspect either appeared early (Position 2) or late (Position 6) in the lineup. Innocent suspects placed in Position 6 were chosen more frequently by participants in the nonbackloaded condition than in either backloaded condition. Additionally, when the lineup was not backloaded, foil identification rates increased from Positions 3 to 5, suggesting a gradually shifting response criterion. The results suggest that backloading encourages participants to adopt a more conservative response criterion, and it reduces or eliminates the tendency for the criterion to become more lenient over the course of the lineup. The results underscore the absolute importance of ensuring that witnesses who view sequential lineups are unaware of the number of individuals to be seen.

Configural and component processing in simultaneous and sequential lineup procedures

“…Typically, when the target (perpetrator) is present, the correct identification rate (or hit rate) is higher in the simultaneous condition, whereas when the target is absent, the false identification rate (or false alarm rate) is lower in the sequential condition (Clark, Howell, & Davey, 2008;Steblay et al, 2001;Steblay, Dysart, & Wells, 2011). These results have been found in event memory studies (e.g., Lindsay & Wells, 1985), in standard face recognition paradigms (e.g., Meissner et al, 2005) and in incidental learning tasks (e.g., Palmer & Brewer, 2012). It has been argued that performance was "superior" in a sequential ineup because the diagnosticity ratio, or the ratio of target to innocent suspect identifications, tends to be larger in the sequential condition (e.g., Steblay et al, 2011).…”

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

“…We did not draw participants' attention to the number of lineup members in our sequential lineups and participants completed a randomized assortment of target-present and target-absent trials. An effect of lineup size may emerge if lineup size is more salient (e.g., Horry et al, 2012;Lindsay et al, 1991), but this could be countered by varying lineup size across trials.…”

“…Lindsay, Lea, and Fulford (1991) and Horry et al (2012) found correct rejections (but not correct identifications) were lower when participants were aware of how many members comprised their sequential lineup. A participant who rejected a sequential lineup in a multiple-trial experiment would discover how many lineup members comprised the lineups, which could lead them to adopt a more lenient criterion for identification as they approached the end of subsequent lineups.…”

“…Sequential lineups involve presenting one lineup member at a time, combined with other procedural components designed to reduce false identifications relative to presenting lineup members simultaneously (simultaneous lineups; Lindsay, Mansour, Beaudry, Leach, & Bertrand, 2009). Normally, sequential lineups are backloaded, which implies to the eyewitness that the lineup contains more people than it actually does, in order to reduce pressure to choose someone (Horry, Palmer, & Brewer, 2012;Lindsay & Wells, 1985). In contrast, the number of lineup members in a simultaneous lineup is immediately obvious.…”

From the Pigeon Lab to the Courtroom

“…To see why, I turn next to the issue of the reliability of eyewitness identification and to the lab-based recognition memory tasks that are most commonly used to investigate it. For decades, this research has been mostly carried out without regard for the distinction between discriminability and response bias (for some notable exceptions, see Ebbesen & Flowe, 2002;Horry, Palmer, & Brewer, 2012;Meissner, Tredoux, Parker, & MacLin, 2005;, and the reported results have had a profound effect on practices in the legal system. Without the guidance of basic theories of recognition memory (theories that protect one from compelling but often faulty intuitions), the argument can be made that eyewitness identification researchers got it wrong in several ways .…”