Lindsay, R. C. L. & Bellinger, K. (1999). Alternatives to the sequential lineup: The importance of controlling the pictures. Journal of Applied Psychology, 84, 315-321.
The use of lineups for identification purposes has a long and varied history in policing and has resulted in the development and implementation of a number of techniques. Although "live" lineups were traditionally employed, police services have increasingly begun to rely on the use of photographic lineups for identification purposes. One of the more common photographic lineup techniques employed is the simultaneous lineup in which police officers present the photographs of all lineup members (i.e., the suspect and several "foils") to the witness at the same time and ask them to select the perpetrator. Although this approach is significantly more cost effective and easier to perform than a live lineup, research indicates that this technique may also increase the likelihood of a mistaken identification. Wells (1984), for example, argues that increased levels of false identification may occur because witnesses are using a "relative judgment" strategy in which they select the face that best matches their memory for the perpetrator relative to other faces in the lineup. As such, a witness may select a face because it is the one that most closely resembles the perpetrator compared to the other lineup members rather than because it is in fact the perpetrator.
Based on the above, Lindsay and Wells (1985) investigated the effectiveness of using a "sequential" lineup in an attempt to control for the relative judgment strategy. This procedure requires the witness to view the lineup members one at a time, limiting his or her ability to select the face that most closely resembles the perpetrator relative to the other lineup members. In other words, the witness or victim must rely upon a more direct comparison between his or her memory for the perpetrator and each face that is presented, using what researchers have termed an "absolute" judgment strategy. Based on the results of several research studies, Turtle, Lindsay and Wells (2003) argue that the sequential lineup procedure significantly reduces the likelihood of mistaken identifications when compared to the simultaneous lineup procedure.
One major concern with the use of the sequential lineup, however, has been the potential for lineup administrators to provide the witness with unintentional cues about the location of the suspect in the lineup (Wells, Small, Penrod, Malpass, Fulero, & Brimacombe, 1998). In response to this concern, police officers have increasingly begun to modify the original sequential lineup procedure to provide the witness with more control of the photographs and subsequently decrease the possibility of providing unintentional cues about the identity of the suspect. These modifications frequently involved instructing the witness on how to self-administer the lineup in sequential form and then leaving the witness alone to view the lineup photographs. Although this adaptation may result in a lower likelihood of bias through unintentional cues, there is clearly a question about whether this change significantly impacts the integrity of the sequential procedure.
In their study, Lindsay and Bellinger (1999) investigated just this question. Specifically, the authors sought to investigate whether such a change in the administration of the lineup would influence the witness's behavior and alter the effectiveness of the sequential procedure. They sought to determine the importance of officer versus witness control of the photographs in a sequential lineup, and the effects of several variations to the sequential procedure. Lindsay and Bellinger became interested in these questions when they consulted with several police officers that were using variations of the sequential and simultaneous lineups that they had designed to increase witness control over the lineup photographs. …