Cops and robbers (and eyewitnesses): a comparison of lineup administration by robbery detectives in the USA and Canada

Abstract

The purpose of this study was to determine how American and Canadian robbery detectives collect identification evidence and whether their practices are consistent with published guidelines. Via a survey, we asked about the use of various lineup practices (e.g., single-blind vs. double-blind administration, sequential vs. simultaneous presentation, and videotaping). Canadian detectives are more likely to use research-based reforms such as double-blind sequential lineups and videotaping. We also assessed how robbery detectives interact with eyewitnesses at four points during a lineup: prior to the lineup, immediately after an identification, and after 12 seconds and 3 minutes have elapsed without an identification. Results showed that at the latter two junctures, officers from both the countries question eyewitnesses in subtle ways that could influence the likelihood of choosing and confidence in the selection. Canadian detectives are less likely than American detectives to do so, however. This finding can be explained by the absence of written guidelines in most US jurisdictions on how officials should interact with eyewitnesses during lineups.

Keywords:

• eyewitness identification
• lineups
• feedback effects
• subtle influence
• lineup reforms

Notes

1. The Sophonow guidelines tell detectives to question the witness about the degree of certainty following a positive identification from a live lineup but admittedly say nothing about a certainty rating subsequent to a positive identification from a photospread.

2. Although they do not explicitly recommend double-blind presentation of sequential lineups, as the vast bulk of empirical research would suggest is the preferred procedure.