Judging the Credibility of Criminal Suspect Statements: Does Mode of Presentation Matter?

Strong, but Wrong: Lay People's and Police Officers' Beliefs about Verbal and Nonverbal Cues to Deception

The present study investigated the beliefs of students and police officers about cues to deception. A total of 95 police officers and 104 undergraduate students filled out a questionnaire addressing beliefs about cues to deception. Twenty-eight verbal cues were included in the questionnaire, all extracted from verbal credibility assessment tools (i.e., CBCA, RM, and SCAN). We investigated to what extent beliefs about nonverbal and verbal cues of deception differed between lay people (students) and police officers, and whether these beliefs were in agreement with objective cues known from research. Both students and police officers believed the usual stereotypical, but non-diagnostic (nonverbal) cues such as gaze aversion and increased movement to be indicative of deception. Yet, participants were less inclined to overestimate the relationship between verbal cues and deception and their beliefs fitted better with what we know from research. The implications of these findings for practice are discussed.

Mental illness, criminal risk factors and parole release decisions

Research has not examined whether higher rates of parole denial among inmates with mental illness (MI) are the result of the increased presence of criminal risk factors among this population. Employing a representative sample of inmates with (n  =  219) and without (n  =  184) MI receiving parole release decisions in 2007, this study tested whether the central eight risk factors for recidivism considered in parole release decisions intervened in the relationship between MI and parole release. MI was associated with possession of a substance use disorder, antisocial personality disorder and violent charges while incarcerated; however, these factors were not related to release decisions. MI was found to have neither a direct nor an indirect effect on release decisions. While results indicate that release decisions appear, to some extent, to be evidence-based, they also suggest considerable discretion is being implemented by parole board members in release decisions above and beyond consideration of criminal risk factors.

The reliability of lie detection performance

We examined whether individuals' ability to detect deception remained stable over time. In two sessions, held one week apart, university students viewed video clips of individuals and attempted to differentiate between the lie-tellers and truth-tellers. Overall, participants had difficulty detecting all types of deception. When viewing children answering yes-no questions about a transgression (Experiments 1 and 5), participants' performance was highly reliable. However, rating adults who provided truthful or fabricated accounts did not produce a significant alternate forms correlation (Experiment 2). This lack of reliability was not due to the types of deceivers (i.e., children versus adults) or interviews (i.e., closed-ended questions versus extended accounts) (Experiment 3). Finally, the type of deceptive scenario (naturalistic vs. experimentally-manipulated) could not account for differences in reliability (Experiment 4). Theoretical and legal implications are discussed.