Impact of culprit threat and investigative pressure on deceptive eyewitness lineup decisions

Abstract

Deception research has primarily focused on individuals’ ability to detect deception, with emphasis on both laypersons and professionals in controlled settings. In contrast, limited attention has been given to the factors that influence an eyewitness’s decision to engage in deception. The present study addressed this gap by manipulating Culprit Threat and Investigative Pressure using mock-crime videos and vignette-based scenarios. To increase participant engagement and evoke stronger cognitive and emotional responses, a guided imagery approach was implemented, supported by an artificial-intelligence created voice that provided continuous dialogue throughout the study. Participants subsequently viewed a lineup and made an identification decision. Results indicated that participants exposed to threat demonstrated greater accuracy and honesty in their responses, reflected in higher rates of correct identifications in target-present lineups and correct rejections in target-absent lineups, compared to non-threatened participants. These findings were not anticipated and highlight the need for further research on the conditions that influence deceptive behaviour in eyewitness contexts.