Effects of Expert Testimony and Interrogation Tactics on Perceptions of Confessions

Evidence obtained through the process of interrogation is frequently undermined by what can be perceived as overzealous interrogation tactics. Although the majority of psychologically oriented tactics are legally permissible, they nonetheless contribute to innocent suspects confessing to crimes they did not commit. The present study examined the effect of expert testimony and interrogation tactics on perceptions of a confession. 182 undergraduates read a transcript of a homicide trial that varied based on interrogation tactic: implicit threat of punishment (maximization) or leniency (minimization) and expert witness testimony (presence or absence of expert testimony). Analysis indicated that the type of interrogation tactic used in obtaining the confession affected participants\u27 perceptions of the coerciveness of the interrogation process

“Supposing that truth is a woman, what then?” The Lie Detector, The Love Machine and the Logic of Fantasy

One of the consequences of the public outcry over the 1929 St Valentine’s Day massacre was the establishment of a Scientific Crime Detection Laboratory at Northwestern University. The photogenic “Lie Detector Man”, Leonarde Keeler, was the Laboratory’s poster boy and his instrument the jewel in the crown of forensic science. The press often depicted Keeler gazing at a female suspect attached to his “sweat box”; a galvanometer electrode in her hand, a sphygmomanometer cuff on her arm and a rubber pneumograph tube strapped across her breasts. Keeler’s fascination with the deceptive charms of the female body was one he shared with his fellow lie detector pioneers, all of whom met their wives – and in William Marston’s case his mistress too – through their engagement with the instrument. Marston employed his own “Love Meter”, as the press dubbed it, to prove that “brunettes react far more violently to amatory stimuli than blondes”. In this paper I draw on the psychoanalytic concepts of fantasy and pleasure to argue that the female body played a pivotal role in establishing the lie detector’s reputation as an infallible and benign mechanical technology of truth

Interrogating to detect deception and truth : effects of strategic use of evidence

Several decades of research has shown that people are poor at detecting deception. This thesis, based on four empirical studies, aimed at exploring human deception detection accuracy in the context of interrogations. In three of the studies, there was a special focus on the presence of evidence in the interrogation, and how strategic use of this evidence affected the statements of the suspects as well as the accuracy of the lie-catchers. In previous research, the fact that there in real-life situations often exists evidence against a suspect has been neglected. It was expected that it would be beneficial for deception detection to withhold the evidence during the interrogation, and that this would lead to liars contradicting the incriminating information to a higher degree compared to truth tellers. Differences in statement-evidence consistency between liars and truth tellers could then serve as a cue leading to more accurate veracity judgments. In Study I, experienced police officers (N = 30) were set free to conduct interrogations with mock suspects in the manner of their own choice. They also watched a video-taped interrogation conducted by one of their colleagues. Both when interrogating and observing video, the police officers achieved deception detection accuracy levels (56.7%) similar to the level of chance. The aim of Study II was to examine the effects of disclosing the evidence at different stages of the interrogation. It was expected that disclosing the evidence late (vs. early) in the interrogation would provide a better basis for correct veracity judgments. The reason for this was that late disclosure of evidence would make liars and truth tellers differ in terms of statement-evidence consistency. Mock suspects (N = 58) were interrogated by experimenters. Lie-catchers (N = 116) who watched late disclosure interrogations (accuracy 61.7%) significantly outperformed those who watched early disclosure interrogations (accuracy 42.9%). In Study III, police trainees (N = 82) either were or were not trained in strategically using the evidence when interrogating lying or truth telling mock suspects (N = 82). Liars interrogated by trained interrogators were more inconsistent with the evidence compared to liars interrogated by untrained interrogators. Trained interrogators obtained a considerably higher accuracy rate (85.4%) than untrained interrogators (56.1%). In Study IV, the strategies reported by the suspects (N = 82) in Study III were examined. Guilty suspects, to a higher degree than innocent suspects, applied conscious strategies in order to appear truthful. Guilty suspects reported diverse strategies (such as to provide a consistent story or an alibi), while innocent suspects reported the strategy to tell the truth like it had happened, indicating a belief in the visibility of innocence (i.e., they thought that innocence shows). The results of the thesis show that when the evidence is not used strategically during an interrogation, deception detection accuracy is poor. However, when the evidence is used strategically, liars and truth tellers resort to different strategies, resulting in differences in statement-evidence consistency. This objective cue to deception provides a good basis for judging a suspect’s veracity

Countering Countermeasures: Detecting Identity Lies by Detecting Conscious Breakthrough

One major drawback of deception detection is its vulnerability to countermeasures, whereby participants wilfully modulate their physiological or neurophysiological response to critical guilt-determining stimuli. One reason for this vulnerability is that stimuli are usually presented slowly. This allows enough time to consciously apply countermeasures, once the role of stimuli is determined. However, by increasing presentation speed, stimuli can be placed on the fringe of awareness, rendering it hard to perceive those that have not been previously identified, hindering the possibility to employ countermeasures. We tested an identity deception detector by presenting first names in Rapid Serial Visual Presentation and instructing participants to lie about their own identity. We also instructed participants to apply a series of countermeasures. The method proved resilient, remaining effective at detecting deception under all countermeasures