Innocent of the crime under investigation: suspects’ counter-interrogation strategies and statement-evidence inconsistency in strategic vs. non-strategic interviews

ABSTRACT

The study examines the counter-interrogation strategies applied by mock suspects (N?=?94), who are innocent of a mock crime under investigation but who were present at the scene, for different reasons, at around the time the crime occurred. Half were present at the crime scene to carry out a lawful act, the other half to carry out an unlawful act. Furthermore, this study examines the effect of the Strategic Use of Evidence (SUE) technique as a strategic interviewing technique (vs. a non-strategic technique), on suspects’ statement-evidence inconsistencies. Participants were randomly assigned to the two interview conditions (strategic vs. non-strategic) and were interviewed as suspects of a crime, which none of them had committed. The results show that the most commonly used counter-interrogation strategy in both groups was to be honest. However, 26.1% of the innocent suspects, performing an unlawful act, reported the strategy to be deceptive. In addition, the statements of suspects executing an unlawful act were significantly more inconsistent with the evidence in the strategic than the non-strategic interview condition. The increased statement-evidence inconsistency rates potentially put these suspects at risk of being assessed as guilty of a crime they did not commit.     

True and false intentions: asking about the past to detect lies about the future

This study is on how to discriminate between true and false intentions, an emerging area within psycholegal research. We argue that asking about the past (the planning phase) might be a promising way to detect lies about the future (intentions). That is, participants who had developed false intentions to mask their criminal intentions were assumed to provide equally long and detailed answers to questions about intentions, compared to participants who told the truth about their intentions. In contrast, we predicted that lying participants would be worse at answering questions about the planning of their stated (false) intentions, compared to participants telling the truth about the planning of their stated (true) intentions. To test our assumptions, we used a newly devised experimental set-up accommodating the main characteristics of intent. Both lying and truth-telling suspects perceived the questions on planning as more unanticipated, and more difficult to answer, compared to the questions about their intentions (future actions). Furthermore, in support of our predictions we found that the truth-telling (vs. lying) suspects' answers to questions on planning were longer and perceived as more detailed and clear, whereas liars' and truth-tellers' answers to questions on intentions were equally long and perceived as equally detailed.     

Training Police Investigators to Interview to Detect False Intentions

This study is the first to investigate police investigators’ adherence to, and the effectiveness of, a training program for detecting true and false intentions. Experienced police investigators (N = 53) were either trained or not trained in how to interview to discriminate between true and false intentions. All investigators interviewed mock suspects (N = 53), of which half lied and half told truth about their intentions. Both subjective and objective measures showed that the trained investigators interviewed in line with the training received. That is, a large proportion asked about the planning of the stated intentions. Noteworthy, none of untrained investigators reported to have posed such questions for strategic purposes. The trained investigators reached a higher detection accuracy level (65 %) than their untrained colleagues (55 %), however not significantly. Given that the investigators adhered to the training, this training package is a viable starting point for developing more effective training programs.