“I’d Know a False Confession if I Saw One”: A Comparative Study of College Students and Police Investigators

College students and police investigators watched or listened to 10 prison inmates confessing to crimes. Half the confessions were true accounts; half were false—concocted for the study. Consistent with much recent research, students were generally more accurate than police, and accuracy rates were higher among those presented with audiotaped than videotaped confessions. In addition, investigators were significantly more confident in their judgments and also prone to judge confessors guilty. To determine if police accuracy would increase if this guilty response bias were neutralized, participants in a second experiment were specifically informed that half the confessions were true and half were false. This manipulation eliminated the investigator response bias, but it did not increase accuracy or lower confidence. These findings are discussed for what they imply about the post-interrogation risks to innocent suspects who confess.     

Polygraph Examiner Awareness of Crime-Relevant Information and the Guilty Knowledge Test

A mock-theft experiment was designed to examine the efficiency of the Guilty Knowledge Test when (a) the examiner was aware of some of the crime-relevant items; (b) target items (i.e., items that are significant to participants for reasons other than crime-relevance) were incorporated into the test; (c) the motivation of guilty participants to appear innocent was manipulated. Results indicated that (a) participants yielded weaker responses to relevant items when the examiner was aware of them than when he did not have the knowledge; (b) the inclusion of target items had no overall effect on the responses to the relevant items: (c) within the guilty condition, highly motivated participants were more responsive to the relevant items than less motivated participants, and the inclusion of target items significantly decreased detection accuracy of low motivated participants.     

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.     

Interviewing to Elicit Cues to Deception: Improving Strategic Use of Evidence with General-To-Specific Framing of Evidence

Previous research has demonstrated that the strategic use of evidence (SUE) approach of interviewing criminal suspects is effective at eliciting cues to deception. This study aims at expanding on the SUE approach by testing the technique of general-to-specific evidence framing. We conducted an experiment using a mock terrorism paradigm. Guilty participants took part in a simulated act of terrorism, while innocent participants performed a similar act involving no transgression. All participants (N?=?102) were then interviewed using one of four evidence disclosure styles (early disclosure, late disclosure, 2-step disclosure, or 4-step disclosure). We expected that disclosing evidence to the suspect gradually, with increasing specificity, would induce guilty suspects to alter their statements to a greater extent than innocent suspects. General-to-specific evidence framing effectively discriminated between guilty and innocent suspects, but results only partially supported the hypotheses.     

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.     

The Comparison Question Test: Does It Work and If So How?

In a mock crime study of the comparison question test (CQT), 35 subjects decided to participate as guilty and 30 as innocent. Two conditions were varied: Explaining the comparison questions in the pretest interview and re-discussing comparison questions between charts. Higher identification rates (approximately 90% for guilty and innocent participants) were achieved in groups with explanation of comparison questions than in groups without explanation. Re-discussing comparison questions had no effect on identification rates. Ratings of subjective stress due to relevant and comparison questions were also obtained and can be seen as indicators of the significance of the questions. The significance of comparison questions was hardly affected by the different testing conditions. When effects are detectable at all, they contradict theoretical expectations in their direction. Results are discussed in terms of the significance of comparison questions used in polygraph testing.     

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.     

Why People Waive Their Miranda Rights: The Power of Innocence

In a laboratory experiment, 72 participants who were guilty or innocent of a mock theft were apprehended for investigation. Motivated to avoid prosecution and trial, they were confronted by a neutral, sympathetic, or hostile male "detective" who sought a waiver of their Miranda rights. Later, 72 other participants watched videotapes of these sessions and answered questions about the detective and suspect. Strikingly, results showed that although the detective's demeanor had no effect, participants who were truly innocent were significantly more likely to sign a waiver than those who were guilty. Naively believing in the power of their innocence to set them free, most waived their rights even in the hostile detective condition, where the risk of interrogation was apparent. The conceptual and policy implications of these results are discussed.     

Who should I look at? Eye contact during collective interviewing as a cue to deceit

Pairs of liars and pairs of truth tellers were interviewed and the amount of eye contact they made with the interviewer and each other was coded. Given that liars take their credibility less for granted than truth tellers, we expected liars to monitor the interviewer to see whether they were being believed, and to try harder to convince the interviewer that they were telling the truth. It was hypothesised that this monitoring would manifest itself through more eye contact with the interviewer and less eye contact with each other than in the case of truth tellers. A total of 43 pairs of participants took part in the experiment. Truth tellers had lunch in a nearby restaurant. Liars took some money from a purse, and were asked to pretend that instead of taking the money, they had been to a nearby restaurant together for lunch. Pairs of liars looked less at each other and displayed more eye contact with the interviewer than pairs of truth tellers. The implications of these findings are discussed.     

Information does not affect the validity of a comparison question test

Purpose . Detailed information about the comparison question test (CQT) and possible countermeasures are now available on the Internet. This study examined whether the provision of such information would affect the validity of the Test for Espionage and Sabotage, a directed lie variant of the CQT. Method . Forty participants were divided into four equal groups: guilty, guilty informed, innocent, and innocent informed. During a first appointment, participants either did or did not commit a mock crime: then some were provided with a book containing detailed information on the CQT, including possible countermeasures. After 1 week with the book, all participants were administered a CQT during their second appointment. Following the polygraph, participants responded to a questionnaire that asked them about their behaviour and perceptions during their examination. Results . There were no significant effects of providing information on the validity of the CQT. However, the reported use of countermeasures was associated with a lower probability of truthfulness. Results of the debriefing questionnaire were found to support predictions made by the theory of the CQT. Conclusions . Concerns that readily available information will enable guilty individuals to produce false‐negative errors seem unfounded. Moreover, the results actually indicate that the use of countermeasures was associated with a lower probability of truthfulness, which was exactly the opposite outcome predicted by the CQT critics.     

Can someone fabricate verifiable details when planning in advance? It all depends on the crime scenario

In the current study we examined the effect of having the opportunity to plan an alibi in advance on the suitability of the verifiability approach in two crime scenarios that differed in their opportunity to carry out innocent activities at the time of the crime. One hundred and two participants imagined being involved in stealing money either from a café at a time when it was open (allows innocent activities) or from a bank at a time when it was closed (does not allow innocent activities). We asked participants about their strategies and difficulties in preparing a verifiable alibi in advance, and to write down their prepared alibis. The participants in both groups found this task difficult and did not differ in the difficulties they experienced, however they differed in their strategies (plans to include true witnesses) and actual success in the task. Participants in the Café scenario provided 30% more verifiable details than the participants in the Bank scenario. Strategies and difficulties mentioned by the participants are presented in the paper, and the implications of the study's results on the application of the verifiability approach are discussed.     

Behavioral Confirmation in the Interrogation Room: On the Dangers of Presuming Guilt

A two-phased experiment tested the hypothesis that the presumption of guilt that underlies police interrogations activates a process of behavioral confirmation. In Phase I, 52 suspects guilty or innocent of a mock theft were questioned by 52 interrogators led to believe that most suspects were guilty or innocent. Interrogators armed with guilty as opposed to innocent expectations selected more guilt-presumptive questions, used more interrogation techniques, judged the suspect to be guilty, and exerted more pressure to get a confession—particularly when paired with innocent suspects. In Phase II, neutral observers listened to audiotapes of the suspect, interrogator, or both. They perceived suspects in the guilty expectations condition as more defensive—and as somewhat more guilty. Results indicate that a presumption of guilt sets in motion a process of behavioral confirmation by which expectations influence the interrogator's behavior, the suspect's behavior, and ultimately the judgments of neutral observers.     

Improving the Comprehensibility of a Canadian Police Caution on the Right to Silence

Modifications to a Canadian police caution on the right to silence were made in an attempt to increase its comprehensibility. University participants were asked to imagine themselves in an arrest and interrogation situation in which they were either innocent or guilty. It was hypothesized that participants who received the modified caution would score significantly higher on measures of comprehension than those who received the standard caution. Results indicated that comprehension was significantly higher among those that received the modified caution and that those with higher comprehension scores were more likely to exercise their right to silence. These findings suggest that clarifying and standardizing how a detainee’s rights are communicated will lead to better comprehension and greater protection against false or coerced confessions.     

Effect of two types of control questions and two question formats on the outcomes of polygraph examinations

Abstract: Two major variations of polygraph “Control Question” testing, the Zone Comparison (ZoC) and the Modified General Question Test (MGQT) were evaluated. Within each, the type of control question, Exclusive or “time bar” (e.g., “Before you were 21, did you ever...”) and Nonexclusive or “no time bar”(e.g., “Did you ever….?”) was manipulated in a mock theft scenario, with 80 male and 40 female subjects randomly assigned to be either innocent or guilty. Polygraphic data collected by experienced field examiners were numerically scored by an evaluator blind to all aspects of the study. Decision accuracy was not related to the type of procedure (ZoC/MGQT) used or the subject’s sex. Accuracy was significantly related to the type of control question [χ²(2) = 11.46, p = 0.003; τc = 0.29]. Nonexclusive control questions produced greater accuracy than Exclusive control questions on both innocent and guilty subjects. These results and subjects’ self‐reports support the general “theory” on which control question (CQ) testing is based. The need for better empirical support of accepted dogma and current field practices is strongly indicated by these findings.     

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.     

Limitations on the ability to negotiate justice: attorney perspectives on guilt,innocence, and legal advice in the current plea system

In the American criminal justice system the vast majority of criminal convictions occur as the result of guilty pleas, often made as a result of plea bargains, rather than jury trials. The incentives offered in exchange for guilty pleas mean that both innocent and guilty defendants plead guilty. We investigate the role of attorneys in this context, through interviews with criminal defense attorneys. We examine defense attorney perspectives on the extent to which innocent defendants are (and should be) pleading guilty in the current legal framework and investigate their views of their own role in this complex system. We also use a hypothetical case to probe the ways in which defense attorneys consider guilt or innocence when providing advice on pleas. Results indicate that attorney advice is influenced by guilt or innocence, but also that attorneys are limited in the extent to which they can negotiate justice for their clients in a system in which uncertainty and large discrepancies between outcomes of guilty pleas and conviction at trial can make it a sensible option to plead guilty even when innocent. Results also suggest conflicting opinions over the role of the attorney in the plea-bargaining process.     

Innocent of the crime under investigation: suspects’ counter-interrogation strategies and statement-evidence inconsistency in strategic vs. non-strategic interviews

ABSTRACT

The study examines the counter-interrogation strategies applied by mock suspects (N?=?94), who are innocent of a mock crime under investigation but who were present at the scene, for different reasons, at around the time the crime occurred. Half were present at the crime scene to carry out a lawful act, the other half to carry out an unlawful act. Furthermore, this study examines the effect of the Strategic Use of Evidence (SUE) technique as a strategic interviewing technique (vs. a non-strategic technique), on suspects’ statement-evidence inconsistencies. Participants were randomly assigned to the two interview conditions (strategic vs. non-strategic) and were interviewed as suspects of a crime, which none of them had committed. The results show that the most commonly used counter-interrogation strategy in both groups was to be honest. However, 26.1% of the innocent suspects, performing an unlawful act, reported the strategy to be deceptive. In addition, the statements of suspects executing an unlawful act were significantly more inconsistent with the evidence in the strategic than the non-strategic interview condition. The increased statement-evidence inconsistency rates potentially put these suspects at risk of being assessed as guilty of a crime they did not commit.     

The role of confirmation bias in suspect interviews: A systematic evaluation

Purpose. The three studies presented in this paper systematically examined the effect of expectations of guilt on interviewer questioning style, confession, denial rates, and suspects' verbal behaviour during interview. Method. Undergraduate students were recruited to participate in the three studies. In Study 1, 61 participants formulated questions that they wanted to ask a suspect to determine whether or not they cheated on a task. Prior to formulating their questions, participants were led to believe that the suspect was likely to be guilty or innocent. In Study 2, 45 ‘innocent’ and ‘guilty’ participants were accused of cheating on a task and were interviewed with either guilt‐presumptive questions or neutral questions. In the final study, 58 participants listened to a selection of audiotaped interviews from Study 2. They then rated various aspects of the suspects' verbal behaviour. Results. As hypothesized expectations of guilt resulted in the formulation of more guilt‐presumptive questions even when participants were free to generate their own questions (Study 1). A significant association was found between suspect guilt/innocence and whether they confessed or denied, although there was no association between questioning style and confession or denial rates (Study 2). However, as expected, ratings of independent observers who listened to tape recordings of the suspect interviews indicated an influence of questioning style on the suspects' verbal behaviour whereby a self‐fulfilling prophecy effect occurred (Study 3). Conclusions. These results indicate that expectations of guilt can indeed have an effect on questioning style and that this in‐turn can lead to a self‐fulfilling prophecy effect.     

Criteria-Based Content Analysis: An empirical test of its underlying processes

Abstract

Criteria-Based Content Analysis (CBCA) is a tool to assess the veracity of written statements, and is used as evidence in criminal courts in several countries in the world. CBCA scores are expected to be higher for truth tellers than for liars. The underlying assumption of CBCA is that (i) lying is cognitively more difficult than truth telling, and (ii) that liars are more concerned with the impression they make on others than truth tellers. However, these assumptions have not been tested to date. In the present experiment 80 participants (undergraduate students) lied or told the truth about an event. Afterwards, they completed a questionnaire measuring “cognitive load” and “tendency to control speech”. The interviews were transcribed and coded by trained CBCA raters. In agreement with CBCA assumptions, (i) truth tellers obtained higher scores than liars, (ii) liars experienced more cognitive load than truth tellers, and (iii) liars tried harder to control their speech. However, cognitive load and speech control were not correlated with CBCA scores in the predicted way.     

Comparative analysis of true or false statements with the source monitoring model and the cognitive interview: special features of the false accusation of innocent people

Abstract

We describe two experiments designed to verify whether the source monitoring (SM) model categories and the cognitive interview (CI) contribute to distinguishing true from false statements. We used a 2 Type of Interview (Structured/Cognitive) × 2 Statement Condition (True/False) design with 18 interviewers in a sample group of 240 gender-matched university students being interviewed about a film fragment. In Experiment 1, participants who lied exculpated the protagonist from rape, whereas in Experiment 2 their lies were aimed at accusing an innocent person. As dependent variables we used criteria from the SM: details, supporting memories, thoughts and feelings and cognitive operations. The results suggest that the statements of honest participants interviewed using the CI provided more overall information than those obtained under any other condition. When a lie is aimed at exculpating someone from criminal behaviour, statements involve more cognitive operations and less sensory, temporal and contextual information, but only when the structured interview (SI) is used. When the lie is aimed at falsely accusing someone, the SI and the CI produce similar results. We discuss the forensic importance of these findings.