Challenging interviewees during interviews: The potential effects on lie detection

Abstract

The impact of interview styles on lie detection was examined. Thirty-six truth tellers and liars (undergraduates) were interviewed in three different ways: The interview started with an information-gathering interview style (Phase 1), which then developed into an interrogation (Phase 2), and finally transformed back into an information-gathering interview style (Phase 3). On the basis of DePaulo and Kirkendol's Motivational Impairment Effect, which suggests that when people are highly motivated to get away with their lies they actually look like they are controlling their behavior, it was hypothesized that the most prominent differences between liars and truth tellers would emerge in Phase 3. The findings supported this hypothesis, and thus suggest that specific interview styles could facilitate lie detection.     

Police officers’ judgements of veracity,tenseness, cognitive load and attempted behavioural control in real-life police interviews

Abstract

The present experiment examined the apparently incongruent findings that police officers (i) believe that suspects show nervous behaviour when they lie but (ii) seem able to detect deceit in suspects who do not show nervous behaviours. It was hypothesized that police officers’ judgements about whether a suspect is lying would not be correlated with their judgements regarding whether the suspect is tense, but, instead, would be correlated with their judgements regarding whether suspects are having to think hard or attempting to control their behaviour.

Each of 84 police officers saw seven truths and seven lies told by suspects during their police interviews. Participants in Condition 1 were asked to indicate after each clip whether the suspect was lying, whereas participants in Condition 2 were asked to note after each clip to what extent the suspect appeared to be tense, having to think hard or attempting to control their behaviour. Condition 3 was a combination of Conditions 1 and 2 and participants were asked all the above questions. The findings support the hypotheses and therefore negate the assumption that police officers primarily look for cues of nervousness when they attempt to detect deceit.     

Effectiveness of deception detection training: a meta-analysis

Abstract

A meta-analysis was conducted to determine the overall effectiveness of deception detection training and to identify conditions that may moderate training effectiveness. The analysis was based on a total of 16 studies with 30 separate hypothesis tests, representing the behavior of 2847 trainees. Results indicated that the effect of deception detection training on detection accuracy was positive, significant, and of medium magnitude. Moreover, training effectiveness was moderated by the type of training implemented, training content, trainee expertise, and the type of lie told. Discussion centers on implications for training design and implementation.     

Differential effectiveness of the cognitive interview in a simulation of testimony

The cognitive interview (CI) is a set of forensic evaluation procedures that has proven its efficiency. Nevertheless, little investigation has been made into its usage on witnesses with the intention of lying. With the aim of proving whether the efficiency of the CI is maintained where the witness is lying we carried out two experiments and we included instructions to tell the truth or to lie as independent variables. We used a 2 Type of interview (SI/CI)×2 Statement Condition (True/False)×2 Interviewee Gender (Male/Female) design with 18 interviewers in a sample group of 240 gender-matched university students being interviewed and the classic measures from the CI as dependent variables: the total number of details, details of actions, details about people and details concerning objects. In a first experiment, participants who lied exculpated the protagonist of a film fragment from rape, whereas in a second, those who lied accused an innocent protagonist. The results, in accordance with previous studies, showed a globally better efficiency for CI. Nevertheless, analysing the material based on type of details, this efficiency is only found in details concerning actions and objects. We discuss the forensic importance of these findings.     

A non-standard method for estimating accuracy of lie detection techniques demonstrated on a self-validating set of field polygraph examinations

Abstract

A unique method for estimating field accuracy of the Comparison Question Test (CQT) – a polygraph technique – is presented, based on a combined probabilistic and algebraic model. It is built on paired examinations in criminal cases in which two opposing versions per case have been subjected to polygraph tests. The developed model is ground-truth free, thus there was no need to rely on external criteria of deception (e.g., confessions or physical evidence) in estimating the accuracy of the CQT. Results indicate an accuracy rate of 0.94 in detecting guilty examinees (Sensitivity) with a 0.06 False Negative rate and an accuracy rate of 0.835 (Specificity) with False Positive of 0.165 for the innocents. These figures excluded 20% of the cases that were ruled inconclusive. When no inconclusive calls were allowed, the accuracy rate dropped down to 0.8 with 0.2 error rates for both the guilty and the innocent examinees. The importance of this research stems from its being a field study that due to the unique methodology was not subjected to weaknesses usually found in polygraph field validity studies. This method is applicable to other techniques of deception detection and with some necessary adaptations may be also to eyewitness situations.     

‘I'm a photographer,not a terrorist’: the use of photography to detect deception

When planning large-scale incidents or bombing campaigns, terrorists often conduct reconnaissance research to identify key targets. This may include taking photographs of potential target locations. Identifying an effective real-time method to distinguish between genuine photographers and those with more sinister intent may be beneficial for law enforcement and security agencies. Participants took photographs in a public place with a genuine intent (truth tellers) or sinister intent (liars). After taking these photographs, the participants were approached by an undercover interviewer (a mime artist) who asked them whether he could see the photographs. Later, the participants discussed their photographs in a formal interview. First, liars were less cooperative in their interaction with the undercover interviewer than truth tellers. Second, in the formal interview, liars mentioned some security features that appeared in the photographs more than truth tellers. The findings suggest that ‘using photographs to detect deception’ is a subject that could prove important to explore to benefit forensic and counter-terrorist practice.     

Ⅰ型鸭肝炎病毒间接免疫酶染色检测方法的建立

以蔗糖密度梯度离心提纯的Ⅰ型鸭肝炎病毒(DHV-Ⅰ)免疫兔制备兔抗DHV-Ⅰ抗体,建立了检测石蜡组织切片中DHV-Ⅰ抗原的间接免疫酶染色(indirect immunoperoxidase staining,IIS)方法,并对DHV-Ⅰ强毒人工感染死亡或濒死雏鸭的各个组织器官进行了检测。结果表明,IIS与DHV-Ⅰ感染死亡或濒死雏鸭的肝等呈现阳性反应,与鸭瘟病毒、鸭疫里默氏杆菌、大肠杆菌、沙门菌、多杀性巴氏杆菌感染发病和死亡雏鸭的肝以及健康雏鸭的肝呈现阴性反应。感染DHV-Ⅰ死亡或濒死雏鸭的肝、脾、肾、心、胸腺、腔上囊、胰腺、十二指肠、盲肠、空肠、回肠、直肠的免疫组织化学检测呈阳性或强阳性,DHV-Ⅰ抗原主要分布于感染细胞的细胞质。该IIS法具有良好的特异性,可用于DHV-Ⅰ在感染雏鸭组织细胞中的亚细胞定位、DHV-Ⅰ感染雏鸭的实验室诊断、甲醛固定组织的回顾性诊断。     

采用无创性核磁共振技术进行损伤时间推断初探

目的建立大鼠皮肤损伤核磁共振（nuclear magnetic resonance,NMR）检测方法,探讨其在法医学中应用的意义。方法雄性SD大鼠36只,随机分为皮肤切创和挫伤组,分别在大鼠背部制作皮肤切创和挫伤,各组分别在损伤后0h、4h、8h取皮肤组织及对侧无损伤部位皮肤,检测NMR一维1H谱,观察受创皮肤的分子代谢产物随损伤时间的变化规律。结果挫伤组、切创组背部损伤处皮肤的1H-NMR图谱在损伤后4h和8h分别检测到较多NMR波峰,波峰的高度和总面积也发生了改变,与对照部位皮肤相比,存在显著性差异（P〈0.05）。结论核磁共振技术检测组织代谢产物有望用于损伤经过时间的法医学检验。     

新精神活性物质——芬纳西泮的检验

目的对缴获的嫌疑药片进行定性定量检验。方法采用GC/MS确证、GC/FID内标法定量检验。结果三起不同案件的嫌疑药片,均检出芬纳西泮,含量为0.5%~1.1%。结论不同时间、不同地区缴获的三起数量较大、外观基本相同的嫌疑药片活性成分均为芬纳西泮的检验结果应引起我国禁毒执法部门的高度重视。