Identifying the Bad Guy in a Lineup Using Confidence Judgments Under Deadline Pressure

Abstract

Eyewitness-identification tests often culminate in witnesses not picking the culprit or identifying innocent suspects. We tested a radical alternative to the traditional lineup procedure used in such tests. Rather than making a positive identification, witnesses made confidence judgments under a short deadline about whether each lineup member was the culprit. We compared this deadline procedure with the traditional sequential-lineup procedure in three experiments with retention intervals ranging from 5 min to 1 week. A classification algorithm that identified confidence criteria that optimally discriminated accurate from inaccurate decisions revealed that decision accuracy was 24% to 66% higher under the deadline procedure than under the traditional procedure. Confidence profiles across lineup stimuli were more informative than were identification decisions about the likelihood that an individual witness recognized the culprit or correctly recognized that the culprit was not present. Large differences between the maximum and the next-highest confidence value signaled very high accuracy. Future support for this procedure across varied conditions would highlight a viable alternative to the problematic lineup procedures that have traditionally been used by law enforcement.