Enabling witnesses to actively explore faces and reinstate study-test pose during a lineup increases discriminability

Abstract

Accurate witness identification is a cornerstone of police inquiries and national security investigations. However, witnesses can make errors. We experimentally tested whether an interactive lineup, a recently introduced procedure that enables witnesses to dynamically view and explore faces from different angles, improves the rate at which witnesses identify guilty over innocent suspects compared to procedures traditionally used by law enforcement. Participants encoded 12 target faces, either from the front or in profile view, and then attempted to identify the targets from 12 lineups, half of which were target present and the other half target absent. Participants were randomly assigned to a lineup condition: simultaneous interactive, simultaneous photo, or sequential video. In the front-encoding and profile-encoding conditions, Receiver Operating Characteristics analysis indicated that discriminability was higher in interactive compared to both photo and video lineups, demonstrating the benefit of actively exploring the lineup members' faces. Signal-detection modeling suggested interactive lineups increase discriminability because they afford the witness the opportunity to view more diagnostic features such that the nondiagnostic features play a proportionally lesser role. These findings suggest that eyewitness errors can be reduced using interactive lineups because they create retrieval conditions that enable witnesses to actively explore faces and more effectively sample features.

Keywords: diagnostic feature detection theory; encoding specificity; eyewitness identification; interactive lineup.

Fig. 1.

pROC curves and pAUC statistics. Note. pROC curves and pAUC statistics for simultaneous interactive, simultaneous static photo and sequential video lineups, separated for front (A and B) and profile (C and D) encoding conditions. ROC lines of best fit were plotted from numbers estimated by unequal-variance signal-detection models. Chance-level performance is indicated by dashed lines. For pAUC values (B and D), error lines are 95% CIs.

Fig. 2.

Visualization of the three lineup procedures. Note. Illustrations of the (A) simultaneous photo lineup, (B) simultaneous interactive lineup, and (C) sequential video lineup. In A, six faces were presented simultaneously in frontal pose. In B, six faces were presented simultaneously in frontal pose, and participants used the computer mouse to click on one face and rotate it, then all faces moved jointly together. In C, only one face was presented at a time via a 20-s video in which the face moved fluidly from front to profile, to the opposite profile, and back to the front. Adapted from ref. .