Mock Crime Paradigm Research Articles

Nonverbal cues to deception: insights from a mock crime scenario in a Chinese sample.

Nonverbal behaviors could play a crucial role in detecting deception, yet existing studies on deception cues have largely centered on Western populations, predominantly university students, thus neglecting the influence of cultural and sample diversity. To address this gap, our study explored deception cues within an Asian cultural setting, utilizing a mock crime paradigm. Our sample comprised Chinese participants, including both men and women with various socioeconomic status (SES) backgrounds. Our findings revealed that compared to truth tellers, liars exhibited heightened emotions and an increased cognitive load. Furthermore, liars showed a higher frequency of self-adaptors and a longer duration of gaze aversion. Our findings contribute to a more profound understanding of deception cues within Asian culture and have implications for practical fields such as criminal interrogation.

Non-linear effects of stress on eyewitness memory

The effect of stress on face identification is not yet clear, with recent experiments finding positive, negative and null results. Here we report the results of two experiments examining the effect of stress on eyewitness performance in line-up face recognition tasks. Both experiments use a stress manipulation and live mock crime paradigm to examine the relationship between stress at encoding and subsequent line-up performance. Experiment 1 replicated an experiment by Sauerland et al. (Behav Sci Law. 2016;34(4):580–594) which induced stress using the Maastricht Acute Stress Test. The replication found the same null result as the original experiment. Experiment 2 aimed to address a limitation of many laboratory experiments which dichotomise stress into low and high groups for comparison. As the Yerkes-Dodson law (1908) suggests that a non-linear relationship exists between stress and performance, it was hypothesised that using a low, medium and high stress manipulation might show clearer results than a dichotomous paradigm. The results of Experiment 2 show a non-linear relationship, with no difference between the low and high stress groups but better performance by the middle stress group. The results suggest that a different approach is required in experiments on stress and face recognition, as the stress–performance relationship is likely non-linear. Significance: Non-linear models are better predictors of face recognition in line-up tasks than are linear models. Two group designs provide insufficient resolution to capture the stress–performance relationship.

CAS(ME)3: A Third Generation Facial Spontaneous Micro-Expression Database With Depth Information and High Ecological Validity.

Micro-expression (ME) is a significant non-verbal communication clue that reveals one person's genuine emotional state. The development of micro-expression analysis (MEA) has just gained attention in the last decade. However, the small sample size problem constrains the use of deep learning on MEA. Besides, ME samples distribute in six different databases, leading to database bias. Moreover, the ME database development is complicated. In this article, we introduce a large-scale spontaneous ME database: CAS(ME) 3. The contribution of this article is summarized as follows: (1) CAS(ME) 3 offers around 80 hours of videos with over 8,000,000 frames, including manually labeled 1,109 MEs and 3,490 macro-expressions. Such a large sample size allows effective MEA method validation while avoiding database bias. (2) Inspired by psychological experiments, CAS(ME) 3 provides the depth information as an additional modality unprecedentedly, contributing to multi-modal MEA. (3) For the first time, CAS(ME) 3 elicits ME with high ecological validity using the mock crime paradigm, along with physiological and voice signals, contributing to practical MEA. (4) Besides, CAS(ME) 3 provides 1,508 unlabeled videos with more than 4,000,000 frames, i.e., a data platform for unsupervised MEA methods. (5) Finally, we demonstrate the effectiveness of depth information by the proposed depth flow algorithm and RGB-D information.

Optimizing the selection of fillers in police lineups

A typical police lineup contains a photo of one suspect (who is innocent in a target-absent lineup and guilty in a target-present lineup) plus photos of five or more fillers who are known to be innocent. To create a fair lineup in which the suspect does not stand out, two filler selection methods are commonly used. In the first, fillers are selected if they are similar in appearance to the suspect. In the second, fillers are selected if they possess facial features included in the witness's description of the culprit (e.g., "20-y-old white male"). The police sometimes use a combination of the two methods by selecting description-matched fillers whose appearance is also similar to that of the suspect in the lineup. Decades of research on which approach is better remains unsettled. Here, we tested a counterintuitive prediction made by a formal model based on signal detection theory: From a pool of acceptable description-matched photos, selecting fillers whose appearance is otherwise dissimilar to the suspect should increase the hit rate without affecting the false-alarm rate (increasing discriminability). In Experiment 1, we confirmed this prediction using a standard mock-crime paradigm. In Experiment 2, the effect on discriminability was reversed (as also predicted by the model) when fillers were matched on similarity to the perpetrator in both target-present and target-absent lineups. These findings suggest that signal-detection theory offers a useful theoretical framework for understanding eyewitness identification decisions made from a police lineup.

Using Polygraph to Detect Passengers Carrying Illegal Items.

The present study examined the effectiveness of a Modified-Comparison Questions Technique, used in conjunction with the polygraph, to differentiate between common travelers, drug traffickers, and terrorists at transportation hubs. Two experiments were conducted using a mock crime paradigm. In Experiment 1, we randomly assigned 78 participants to either a drug condition, where they packed and lied about illicit drugs in their luggage, or a control condition, where they did not pack or lie about any illegal items. In Experiment 2, we randomly assigned 164 participants to one of the two conditions in Experiment 1 or an additional bomb condition, where they packed and lied about a bomb in their luggage. For both experiments, we assessed participants’ RR interval, heart rate, peak-to-peak amplitude of Galvanic Skin Response (GSR) and all three combined, using Discriminant Analyses to determine the classification accuracy of participants in each condition. In both experiments, we found decelerated heart rates and increased peak-to-peak amplitude of GSR in guilty participants when lying in response to questions regarding their crime. We also found accurate classifications of participants, in both Experiment 1 (drug vs. control: 84.2% vs. 82.5%) and Experiment 2 (drug vs. control: 82:1% vs. 95.1%; bomb vs. control: 93.2% vs. 95.1%; drug vs. bomb: 92.3% vs. 90.9%), above chance level. These findings indicate that Modified-CQT, combined with a polygraph test, is a viable method for investigating suspects of drug trafficking and terrorism at transportation hubs such as train stations and airports.

Linguistic Cues of Deception Across Multiple Language Groups in a Mock Crime Context

AbstractA recent study showed that specific linguistic and grammatical features of a technique commonly referred to as statement analysis are applicable across different language groups. One limitation of that study was that it used an eyewitness crime video paradigm, which might be different from writing a statement after committing an actual criminal act. We remedied that limitation by using a mock crime paradigm. In this study, three language groups (English, Spanish, and Chinese) produced statements after committing a mock crime, taking a check, in an experimental context. Certain linguistic features significantly discriminated truths from lies similarly across the different language groups, suggesting that statement analysis might be applicable as a reliable indicator of deception across languages. Copyright © 2015 John Wiley & Sons, Ltd.

The Effects of Lineup Administrator Influence and Mortality Salience on Witness Identification Accuracy

We manipulated mortality salience, perpetrator presence in the lineup, and administrator steering in a mock crime paradigm to examine whether reminders of one’s mortality increase susceptibility to influence from a lineup administrator. When steered toward the suspect, witnesses were more likely to choose, yielding lower lineup rejection rates than double-blind administration. Further, steering administrators effectively guided non-mortality-salient (but not mortality-salient) witnesses toward suspect identifications, regardless of the suspect’s actual guilt. Mortality salience similarly increased suspect identifications relative to the double-blind, non-mortality-salient condition. We discuss the implications of these results for the external validity of laboratory eyewitness research.

Detecting truth in suspect interviews: the effect of use of evidence (early and gradual) and time delay on Criteria-Based Content Analysis, Reality Monitoring and inconsistency within suspect statements

The strategic use of evidence in interviews with suspects has been shown to increase the ability of interviewers to accurately and consistently distinguish truthful from deceptive accounts. The present study considers the effect of early and gradual revelation of evidence by the interviewer, and the effect of shorter and longer delay on the verbal quality of truth-teller and liar statements within a mock crime paradigm. It was hypothesised that gradual disclosure of evidence (1) in terms of inconsistencies (a) within statements and (b) between statements and such evidence and (2) of the criteria of Criteria-Based Content Analysis (CBCA) and of Reality Monitoring (RM) would emphasise differences in the verbal quality of truth-teller and liar statements. Forty-two high school students took part in the study. The use of statement-evidence and within-statement inconsistency appears to be a robust cue to deception across interview style and delay. This indicates that gradual disclosure in interviews may increase interviewer accuracy in veracity decisions by eliciting statement inconsistencies. However, gradual revelation and delay affected the ability of CBCA and RM criteria to distinguish the veracity of suspect statements.

Memory detection with the Concealed Information Test: a meta analysis of skin conductance, respiration, heart rate, and P300 data.

The Concealed Information Test (CIT) uses psychophysiological measures to determine the presence or absence of crime-related information in a suspect's memory. We conducted a meta-analysis on the validity of the CIT based on four physiological measures-skin conductance response (SCR), respiration line length (RLL), changes in heart rate (HR), and enhanced amplitudes of the P300 component of the event-related potential (P300). This meta-analysis relied on laboratory studies that used either the mock-crime or the personal-item paradigm. Results showed a mean effect size (d*) of 1.55 for SCR, 1.11 for RLL, 0.89 for HR, and 1.89 for P300. However, P300 outperformed SCR only in the personal-item paradigm, but not in the mock-crime paradigm. Motivation level, number of questions, publication year, and the inclusion of innocent participants emerged as significant moderators for the SCR, while only the type of paradigm used moderated the P300 effect.

Decrements in Miranda abilities: An investigation of situational effects via a mock-crime paradigm.

Programmatic research has made important advances during the last decade in understanding how cognitive and psychological variables affect Miranda comprehension and reasoning. However, the effects of situational stressors are largely overlooked in determining the validity of Miranda waivers. As the first systematic investigation, this study uses a 2×2×2 factorial design on 123 undergraduate participants to examine the effects of being apprehended via a mock crime (i.e., stealing a watch from a Plexiglas case) paradigm on Miranda comprehension and reasoning. Besides the mock-crime condition, the mode of advisement (oral or written) and the length of the warning (124 vs. 228 words) were also investigated. When compared to controls, the mock-crime scenario produced moderate to large effects (ds from .58 to .75) on both Miranda recall and subsequent reasoning. In addition, oral advisements resulted in non-significant trend for decrements in Miranda recall. No main effects were observed for length and no significant interactions were found. Interestingly, specific components (e.g., right to counsel and free legal services) were generally more affected than the more familiar first two components (i.e., right to silence and evidence against you). Within the crime-scenario condition, participants with substantially increased state anxiety predictably performed more poorly than those participants whose state anxiety remained relatively stable. Directions for future research and the implications of these findings on our understanding of Miranda abilities are discussed.

Minimizing culpability increases commission errors in a mock crime paradigm

Purpose. Empirical studies have demonstrated that feigning amnesia undermines memory for a mock crime. Not much is known about the effects of other culpability‐reducing strategies on memory. The present study investigated what strategies participants use when they are instructed to minimize culpability and if these strategies undermine memory to a similar extent as claiming amnesia.Methods. Participants performed a mock crime. Next, they were either instructed to minimize culpability for this mock crime in a simulated interrogation or asked to respond honestly. One week later, memory for the mock crime was tested.Results. None of the participants claimed amnesia when trying to minimize culpability. Conversely, all participants fabricated an alternative account of their role in the crime. Compared with responding honestly on both tests, fabricating an alternative story on the first test undermined memory for the mock crime in terms of commission errors. Correct recall was unaffected. It appeared that this effect was related to story length: the longer the fabricated story, the more the commission errors when telling the truth 1 week later.Conclusions. Fabricating an alternative story (i.e. lying) did not compromise correct recall, but induced more commission errors. The findings are discussed in terms of possible underlying mechanisms.

Déjà vu! The effect of previewing test items on the validity of the Concealed Information polygraph Test

It has been recommended previewing test items with the examinee prior to conducting a Concealed Information polygraph Test. This procedure serves to familiarize the suspect with the test items and allows adjustment, if necessary exclusion, of bad test items. According to the National Research Council (2003), however, this procedure could decrease detection efficiency due to habituation. In two experiments using a mock crime paradigm, this possibility was tested. Guilty and innocent mock crime participants were or were not presented with the test items prior to the administration of a Concealed Information Test. No evidence was found that previewing diminishes detection efficiency of the Concealed Information Test. These findings, together with methodological and legal concerns, support the previewing of test items.

Facial Skin Surface Temperature Changes During a “Concealed Information” Test

When individuals who commit a crime are questioned, they often show involuntary physiological responses to remembered details of that crime. This phenomenon is the basis for the concealed information test, in which rarely occurring crime-related details are embedded in a series of more frequently occurring crime-irrelevant items while respiratory, cardiovascular, and electrodermal responses are recorded. Two experiments were completed to investigate the feasibility of using facial skin surface temperature (SST) measures recorded using high definition thermographic images as the physiological measure during a concealed information test. Participants were randomly assigned to nondeceptive or deceptive groups. Deceptive participants completed a mock-crime paradigm. A focal plane array thermal imaging radiometer was used to monitor SST while crime-relevant and crime-irrelevant items were verbally presented to each participant. During both experiments, there were significant facial SST differences between deceptive and nondeceptive participants early in the analysis interval. In the second experiment, hemifacial (i.e., "half-face" divided along the longitudinal axis) effects were combined with the bilateral responses to correctly classify 91.7% of participants. These results suggest that thermal image analysis can be effective in discriminating deceptive and nondeceptive individuals during a concealed information test.

Psychophysiological and vocal measures in the detection of guilty knowledge

The Guilty Knowledge Test (GKT) and its variant, the Guilty Actions Test (GAT), are both psychophysiological questioning techniques aiming to detect guilty knowledge of suspects or witnesses in criminal and forensic cases. Using a GAT, this study examined the validity of various physiological and vocal measures for the identification of guilty and innocent participants in a mock crime paradigm. Electrodermal, respiratory, and cardiovascular measures successfully differentiated between the two groups. A logistic regression model based on these variables achieved hit rates of above 90%. In contrast to these results, the vocal measures provided by the computerized voice stress analysis system TrusterPro were shown to be invalid for the detection of guilty knowledge.

Feigning amnesia undermines memory for a mock crime

AbstractUsing scripts, previous studies by Christianson and co‐workers have suggested that simulating amnesia undermines memory. Relying on a more realistic mock crime paradigm, the current study examined whether feigning amnesia has memory‐undermining effects. After committing a mock crime, one group of participants (n = 21) was instructed to simulate amnesia for the event. Their performance on immediate free recall tests was compared to that of participants (n = 20) who were instructed to respond honestly during free recall. After one week, simulators, honestly responding controls, and a second control group (n = 20) that had not undergone immediate memory testing after the pertinent event completed free recall tests. This time, all participants were instructed to perform as well as they could.At the follow‐up free recall test, both ex‐simulators and controls who underwent the memory testing for the first time performed significantly worse than the honestly responding controls. Thus, the current study supports the idea that simulating amnesia in order to evade responsibility for a crime has detrimental effects on true memory of the crime. Our results also suggest that this effect can best be understood in terms of lack of rehearsal. Copyright © 2004 John Wiley & Sons, Ltd.

A COMPARISON OF PHYSIOLOGICAL INDICES IN DETECTION OE DECEPTION

ABSTRACTPhysiological measures—breathing amplitude (BA), breathing cycle time (BCT), galvanic skin response (GSR), skin potential response (SPR), systolic blood pressure (BP), oxygen saturation level (O2S), finger volume (FV), and pulse volume (PV)—were compared with respect to their relative efficiency in discriminating deception in a lie detection experiment. Thirty Ss were tested. Stimuli consisted of personal words and neutral words made relevant in the context of a mock crime paradigm. Only GSR, SPR, and FV consistently discriminated better than chance, with GSR and SPR significantly superior to FV. BA and O2S yielded some evidence of discrimination, but were inconsistent across stimulus material.