Detecting truth in suspect interviews: the effect of use of evidence (early and gradual) and time delay on Criteria-Based Content Analysis, Reality Monitoring and inconsistency within suspect statements

Abstract

The strategic use of evidence in interviews with suspects has been shown to increase the ability of interviewers to accurately and consistently distinguish truthful from deceptive accounts. The present study considers the effect of early and gradual revelation of evidence by the interviewer, and the effect of shorter and longer delay on the verbal quality of truth-teller and liar statements within a mock crime paradigm. It was hypothesised that gradual disclosure of evidence (1) in terms of inconsistencies (a) within statements and (b) between statements and such evidence and (2) of the criteria of Criteria-Based Content Analysis (CBCA) and of Reality Monitoring (RM) would emphasise differences in the verbal quality of truth-teller and liar statements. Forty-two high school students took part in the study. The use of statement-evidence and within-statement inconsistency appears to be a robust cue to deception across interview style and delay. This indicates that gradual disclosure in interviews may increase interviewer accuracy in veracity decisions by eliciting statement inconsistencies. However, gradual revelation and delay affected the ability of CBCA and RM criteria to distinguish the veracity of suspect statements.