Perceptions of suspect statements: a comparison of exposed lies and confessions

ABSTRACT

Confrontational interrogation techniques seek to produce a confession, while investigative interviews focus on information gathering and/or catching suspects in lies. Confessions obtained during interrogations are potent for securing a defendant’s conviction. However, the goal of investigative interviews is not to produce a confession, yet it is unknown if their outcome (e.g. exposed lies) is as effective in court as that of an interrogation (i.e. a confession). In two studies, mock jurors read case summaries wherein a defendant was accused of murder and terrorist activities. In both cases, the statement a defendant made during a police interview was manipulated: The defendant either lied or not and either confessed or not. Participants then rendered a verdict and were asked about the probative value of several pieces of supporting evidence. Results were similar across both studies with more convictions when the defendant lied, confessed, or did both relative to when the defendant produced a statement without lies and without a confession. Furthermore, we found that perceptions of supporting evidence mediated the effect of exposed lies on culpability, but this was not the case for confessions. These findings illustrate the positive qualities of presenting exposed lies in court, diminishing the need for a confession.

KEYWORDS:

• Investigative interview
• interrogation
• juror decision making
• lies
• confessions

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1 This effect was determined based on the medium effects found in Kassin and Neumann (1997). We over-recruited in anticipation of participant errors, as the original power analysis for a 2 × 2 ANOVA resulted in a recommended sample of 146. This was also an appropriate sample for our logistic regression following the recommendation of 50 cases per predictor (Aldrich & Nelson, 1984). Accordingly, our sample should have been sufficient to test our primary hypotheses.

2 We asked other questions about the case in general and the interview evidence; however, their purpose was to mask the intent of the study and thus we do not report the results concerning these variables. Questions are available on the first author’s OSF account.

3 We are aware of the ongoing debate as to the utility of manipulation checks (e.g. Fayant, Sigall, Lemonnier, Retsin, & Alexopoulos, 2017). However, in the absence of formal attention checks, we wanted to be sure participants were paying attention to the task. We thus chose to exclude participants who responded wrong to the most straightforward dichotomous variable included in our questionnaires – the full dataset is available on the first author’s OSF account.

4 As with Study 1, we determined sample size with an a-priori power analysis (85% power) to detect a slightly smaller effect (f = .19). This power analysis was conducted, as in Study 1, for a 2 × 2 ANOVA to test our first hypothesis, and resulted in a recommended sample size of 251.

Additional information

Funding

Both authors would like to acknowledge funding by John Jay College of Criminal Justice Ethics Across the Curriculum.