Leif A. Strömwall

Guilty and innocent suspects’ strategies during police interrogations

Abstract Deception detection has largely failed to investigate guilty and innocent suspects’ strategies. In this study, mock suspects (n=82) were interrogated by police trainees (n=82) who either were or were not trained in the technique to strategically use the evidence (the SUE technique). Analyses revealed that guilty suspects to a higher degree than innocent suspects applied strategies in order to appear truthful. Guilty suspects reported diverse strategies, while innocent suspects reported the strategy to tell the truth like it had happened, indicating a belief in the visibility of innocence. The realism in the suspects’ expectation about how their veracity was judged was largely dependent on the way in which they had been interrogated. The truth-telling suspects who were interrogated according to the SUE technique were optimistic about being judged as truthful; this optimism was warranted as the vast majority of them were classified as truthful. The SUE technique seems to help (a) spotting guilty suspects without them being aware of it and (b) spotting innocent suspects, and they become aware of it. That innocent (but not guilty) suspects can read how the interrogator views them is advantageous for the investigative process.

To act truthfully: Nonverbal behaviour and strategies during a police interrogation

Abstract In an experiment, nonverbal indicators of deception in police interrogations of mock crimes were examined. Both vocal and nonvocal behaviours were scored. Thirty participants were subjected to long interrogations (over 9 minutes) conducted by 30 experienced police officers, asked to interrogate as they normally do. Although the liars reported being significantly more nervous, and found the task more strenuous than the truth tellers, no differences in the nonverbal behaviours scored were found. In an analysis of the strategies employed, both truth tellers and liars were found to try to not make excess movements. The principal verbal content strategy for the liars was to keep the story simple, and for truth tellers to keep the story real. The reasons why, in this demanding situation, the truth tellers and liars could not be distinguished by their nonverbal behaviour are discussed.

Police officers' lie detection accuracy: interrogating freely versus observing video

The study investigated experienced police officers’ (N = 30) lie detection accuracy. Each police officer conducted an interrogation of a college student acting as a suspect either guilty or innocent of a mock crime and made a veracity judgment of the suspect. The police officers had the opportunity to conduct the interrogation in the manner of their own choice. The lie detection accuracy of these police officers was compared to that of police officers judging videotaped versions of the interrogations. The police officers failed to detect deception better than chance. There was no difference in accuracy between police officers interrogating live and observing video. The interrogators reported to rely on verbal content more when interrogating than when watching video. It seems as though police officers have a difficult time detecting deception not only in passive contexts but also in active ones.For centuries, philosophers have pondered on the nature of human deception (see e.g., Bok, 1989). However, the scientific approach to human deception is far younger. For some decades, psychologists and scholars within the domain of communication have studied deception as a phenomenon of interpersonal relations (Ekman, 2001). Researchers have also focused on the nature of deception in applied contexts, such as in a forensic one (Granhag & Stromwall, 2004). In the legal system, professionals such as police officers and judges frequently face the task of having to judge the veracity of a person, be it a witness, alleged crime victim or a suspect. These judgments can be of utmost importance in the legal process, and the outcome of the judgments can have farreaching consequences for the person being judged. Detection of deception in the legal system is the focus of the present thesis. More specifically, I will examine the detection of deception in the context of interrogations, with a special focus on the effects of strategic use of the available evidence. Before summarizing the four empirical studies on this topic, I will provide an overview of the research on deception, and describe the relevant literature on interrogating suspects.

Impression and Information Management: On the Strategic Self- Regulation of Innocent and Guilty Suspects

The aim of this study was to increase understanding of the psychology of deception by mapping the reasoning of guilty and innocent mock suspects who deny a transgression. Based on previous research, we proposed that suspects will engage in two major forms of regulation: impression management, which requires the purposeful control of nonverbal and demeanor cues; and information management which involves the regulation and manipulation of speech content to provide a statement of denial. We predicted that truth tellers and liars would both be engaged in impression management, but that that they would differ in the extent to which they will engage in information management. The results supported this prediction: liars and truth tellers reported planning demeanor to the same extent, but differed in the extent to which they reported planning the content of their statement. Self-reported strategies regarding nonverbal behavior were similar for liars and truth tellers, while strategies regarding information differed markedly.

Deception Detection: Interrogators' and Observers' Decoding of Consecutive Statements

Abstract This study is an examination of two forensically important but previously neglected issues in interpersonal deception. First, which cues do lie catchers—who have access to repeated interrogations—pay attention to in order to detect deception? Second, do face-to-face interacting interrogators differ from noninteracting observers in terms of how they perceive a suspect? After watching a staged event, 24 suspects (12 liars and 12 truth tellers) were interrogated three times over a period of 11 days. After the final interrogation, the veracity of each suspect was assessed by his or her interrogator and by 6 observers who had watched the interrogations on video only. The results of the experiment showed that consistency over time was by far the most commonly used cue for justifying veracity judgments. Critically, the predictive accuracy for this cue was alarmingly low. As opposed to results from previous research, the interrogators used verbal cues to a significantly greater extent than did the observers. Furthermore, a probing effect was shown (i.e., probed suspects were perceived as significantly more honest than nonprobed suspects). Finally, limited support for a previously reported honesty effect was obtained (i.e., that interrogators perceive suspects to be more honest than do observers).

Granting asylum or not? Migration board personnel's beliefs about deception

This study investigated beliefs about deception held by Swedish Migration Board personnel working with asylum cases (n=67), and by a control sample of students (n=69). A questionnaire including both closed and open-ended questions was used. The purpose was to achieve further understanding of Migration Board (MB) officers’ beliefs about deception as they assess reliability of individuals from different ethnic backgrounds. In the asylum process, physical evidence is frequently missing, and the ability to distinguish between truth-telling and lying asylum-seekers is hence crucial. Overall, the beliefs held by MB personnel were not more in tune with research findings on objective cues to deception than were the beliefs of the students. In addition, MB personnel often refrained from taking a stand concerning the relation between specific behaviours and deception; they exhibited substantial within-group disagreement and expressed a need for information about issues of deception. The results point to an objective need and a subjective request for education concerning deception detection.

Rape victim and perpetrator blame and the Just World hypothesis: The influence of victim gender and age

Abstract Victims of rape are sometimes blamed for the assaults against them. Research has examined primarily female victims; much less is known about men as victims and whether victim age affects attributions of victim blame. Furthermore, the study investigated the effects of Belief in a Just World (BJW) on blame attributions. Employing a vignette-type experimental study with a 2 (gender of participant)×2 (victims gender)×2 (victims age)×2 (participant BJW score) between-subjects design and several measures of blame attributions towards victim and perpetrator as dependent variables, a community sample (n = 164) participated. The main results were as hypothesised, namely that young male victims were attributed more blame, particularly by participants scoring high on BJW. Overall, victim blame level was low and perpetrator blame was high, and BJW was a powerful predictor of blame attributions.

Detecting deception in suspects: verbal cues as a function of interview strategy

Research on deception has consistently shown that people are poor at detecting deception, partly due to lack of consistent cues to deception. This research focuses on eliciting verbal cues to deception when questioning suspects who deny crime and how such cues differ due to type of questioning. An experiment examined verbal differences between innocent and guilty mock suspects (N=96) as a function of veracity and interview style (Free recall, Probes, or Free recall plus Probes). Guilty (vs innocent) suspects omitted more crime-relevant information and their statements were more likely to contradict the evidence, showing that statement–evidence inconsistency was a cue to deception. This cue to deception was more pronounced when the interview contained probes. Lie-catchers (N=192) obtained an accuracy rate higher than chance (61.5%) for detecting deceptive denials. Implications for further research on verbal cues to deception are discussed.

Children recalling an event repeatedly: Effects on RM and CBCA scores

Purpose. The fact that abused children often talk about their experiences before entering the legal system is a neglected factor in terms of the validation of different reliability assessment techniques. Hence, the present study investigated the extent to which the scores of the reality monitoring technique (RM) and the criteria-based content analysis technique (CBCA) were affected by the number of times children recalled an experienced or an imagined event. Method. Children (aged 12–13 years, N ¼ 80) participated in an experiment where half the sample experienced a real event (an interaction with a stranger outside his car) and then recalled it either one or four times (over a period of 14 days), and the other half imagined the same event and thereafter recalled it either one or four times. The statements given at the final (or only) recall session were analysed with both CBCA and RM. Results. The results revealed that, on a multivariate level, both the CBCA and RM sets of criteria discriminated between truthful and fabricated statements. The total RM score (but not the total CBCA score) discriminated reliably between truthful and fabricated statements. Furthermore, RM (but not CBCA) were sensitive to the number of times the experienced or imagined event was recalled: increased presence of criteria after repeated recall. Conclusions. The results were rather promising for the RM and less so for the CBCA. Furthermore, we found that the number of recalls moderated the effectiveness of the techniques. Hence, when assessing the reliability of a child’s memory, it is crucial to learn about the history of the first documented statement. The outcome of criminal investigations often depends on witness statements, and this is particularly true for cases of alleged child sexual abuse where physical and medical evidence often are lacking. Criteria-based content analysis (CBCA) and reality monitoring (RM) are two techniques that focus on the verbal content of a statement in order to discriminate truthful from fabricated accounts. Several studies have been conducted in order to validate the CBCA technique (for a recent review, see Vrij, 2005).

DECEPTION AMONG PAIRS: ''LET'S SAY WE HAD LUNCH AND HOPE THEY WILL SWALLOW IT!'' DECEPTION AMONG PAIRS

Deception research has neglected the fact that legal-workers often have to try to detect deceit on the basis of statements derived from pairs of suspects, each having been interrogated repeatedly. To remedy this shortcoming we conducted a study where each member of 10 truth-telling pairs and 10 lying pairs was interrogated twice about an alibi. One hundred and twenty undergraduate students were enrolled as lie-catchers. The main findings were that (a) overall deception detection accuracy was modest; (b) lie-catchers given access to a large number of statements did not outperform lie-catchers given access to a lesser number of statements; (c) when asked to justify their veracity assessments the most frequently reported cue was ‘consistency within pairs of suspects’; (d) all cues to deception were of low diagnostic value. Psycho-legal aspects of integrating sequential information in deception detection contexts are discussed.Deception research has neglected the fact that legal-workers often have to try to detect deceit on the basis of statements derived from pairs of suspects, each having been interrogated repeatedly. ...