How Awareness of Possible Evidence Induces Forthcoming Counter‐Interrogation Strategies

Abstract

We propose that suspects' counter-interrogation strategies vary as a function of their perception of the interrogator's knowledge about the events in question. The present study investigates the verbal behavior of guilty and innocent suspects when they are aware that there may be incriminating evidence against them. Participants (N = 143) took part in either a simulated act of terrorism or a benign task. They were then interviewed about their activities. Participants were randomly assigned to receive no additional information or to be informed that an investigative team may have collected evidence from surveillance cameras. Results suggest that when alerted to possible evidence against them, guilty suspects adopt either extremely withholding or extremely forthcoming verbal strategies. Theoretical implications of these results are discussed.

Countermeasures Against the Strategic Use of Evidence Technique: Effects on Suspects' Strategies

“…In a recent study, Luke and his colleagues (in press) informed some of their suspects that the interviewer may have reviewed video surveillance recordings. This manipulation induced a large proportion of guilty suspects to become highly forthcoming.…”

“…the interviewer knew that the suspect had been in the room where the crime took place), but it did specify the source of the evidence (that is, surveillance recordings). The guilty suspect informed about the evidence in the study by Luke and his colleagues (in press) demonstrated a bimodal distribution of forthcomingness: Many suspects were highly withholding, many suspects were highly forthcoming, and few suspects were on the middle of the scale. In the present study, we found a different distribution, wherein guilty‐informed suspects demonstrated more variation in their forthcomingness.…”

“…More specifically, liars tend to provide statements that (a) omit incriminating information and (b) contradict the evidence the interviewer possesses. When they believe the interviewer is more knowledgeable, they attempt to account for this knowledge by providing a statement that is closer to the truth (Luke, Dawson, Hartwig, & Granhag, ). In contrast to liars, truth tellers tend to be more forthcoming with information, regardless of their perception of the interviewer's knowledge.…”

“…Luke et al (in press) recently found that when suspects believe that that evidence against them probably exists—even when they are unaware of the precise nature of that evidence—many guilty suspects become highly forthcoming. These forthcoming guilty suspects did not admit to their involvement in a transgression, but they disclosed numerous accurate details about their activities.…”

“…Relatedly, Oleszkiewicz, Granhag, and Montecinos () found that mock intelligence interviewees provided more information when they believed the interviewer was more knowledgeable. Luke and his colleagues (in press) argued that this use of a forthcoming verbal strategy was aimed at generating a story that did not contradict facts the interviewer knew (cf. Granhag & Hartwig, in press).…”