SCANning for truth. Scholars’ and practitioners’ perceptions on the use(fulness) of Scientific Content Analysis in detecting deception during police interviews

Abstract

SCAN (Scientific Content Analysis) is an analytic method that claims to detect deception in written statements. Although the validity of SCAN is contested in literature, various (law enforcement) agencies across the globe are trained in using the technique. To date it remains unknown how the technique is perceived and to what extent it is used in practice. Based on a scoping review and an open-and closedended survey, we identified practitioners' and scholars' prevailing perceptions on the use(fulness) of SCAN. Data were collected from 48 participants (35 practitioners and 13 scholars). Key findings illuminate a discrepancy between practitioners and academics. While practitioners position themselves positively towards SCAN, academics urge for a complete disappearance of the technique. Practitioners apply an incomplete, personalized version of SCAN. Since SCAN is not applied in its originally designed form and existing research demonstrates the technique has important shortcomings, we advise practitioners to abandon SCAN altogether.

Verbal Lie Detection: Its Past, Present and Future

“…SCAN experts do not create a total score but highlight the criteria they believe are indicative of truth or lie in each statement. The criteria they highlight depend on the statement and on the SCAN expert [ 51 ]. Unsurprisingly, when assessing statements, inter-agreement among SCAN experts is typically low [ 48 ].…”

“…The limitation of the SCAN procedure is that it ignores that truth tellers do not recall all information they know in an unprompted recall [ 70 ]. In addition, practitioners find obtaining written statements problematic because written statements are not common in police interviews [ 51 ]. CBCA is part of SVA which includes an interview protocol (Phase 2).…”