The Influence of Lineup Type on Decision Accuracy, the Use of Decision-Making Processes and Decision Process Accuracy

Abstract

Eyewitness identifications are often a crucial component in securing convictions; unfortunately, research has shown these decisions are sometimes erroneous, which may result in the wrongful conviction of innocent people (Wells, 1978). We examined the impact of sequential and simultaneous lineup presentation on the accuracy of lineup decisions and the decision processes/strategies elicited by each lineup type. We looked at both traditional lineup decision processes and more recently found processes/strategies and their associated accuracy. We did this using think aloud and mock-crime procedures with participants (N = 462). Unexpectedly, simultaneous lineups facilitated more correct rejection than sequential lineups. We also found that relative judgement was a less accurate decision process, but only when the target was absent. As expected, simultaneous lineups elicited more relative judgements, and sequential lineups elicited more instances of automatic recognition. Visualizing and checking/justifying were the most used decision processes/strategies and were equally prominent over simultaneous and sequential lineup types. These findings suggest that simultaneous lineups produce more accurate lineup decisions when the perpetrator is not present and also suggest that the most used decision processes/strategies are not from the traditional dichotomies.