Repeated interrogations:: Verbal and non-verbal cues to deception

The major aim of this study was to investigate to what extent verbal and non-verbal features of liars' and truth-tellers' behaviour change during the course of repeated interrogations. After seeing a staged event, 24 suspects (12 liars and 12 truth-tellers) were interrogated three times over a period of I I days. In terms of the non-verbal features, and in line with our prediction, we found that the liars displayed significantly fewer smiles, self-manipulations, pauses, and less gaze aversion than truth-tellers. Furthermore, over time the initial differences between liars' and truth-tellers' non-verbal behaviour increased for smiles, gaze aversion and pauses. In addition, we found that the cue 'richness of detail-the most indicative verbal marker for truth as given in previous research-had no discriminative power at any of the interrogation sessions. Finally, and in contrast to beliefs held by supposed expert lie-catchers (e.g. judges and police officers), truthful and deceptive statements were found to be equally consistent over time. The psycho-legal implications of the above findings are discussed. Copyright (C) 2002 John Wiley Sons, Ltd.