How Often and Why Do Guilty and Innocent Suspects Confess, Deny, or Remain Silent in Police Interviews?

How Often and Why Do Guilty and Innocent Suspects Confess, Deny, or Remain Silent in Police Interviews? Lennart May, Yonna Raible, Elsa Gewehr, Johannes Zimmermann & Renate Volbert. Journal of Police and Criminal Psychology, Jun 16 2022. https://rd.springer.com/article/10.1007/s11896-022-09522-w

Abstract: This study examines how often and why suspects who have reported being either guilty or innocent remain silent, confess, or deny accusations in police interview situations. Convicted offenders under current probation or parole in Germany (N = 280) completed a questionnaire about their perceptions of up to six specific police interview situations they had experienced in their lifetime. As predicted, more suspects reported having confessed truthfully (64.3%) compared to falsely (4.1%) at least once in their lifetime; and more suspects reported having remained silent in guilty interview situations (58.4%) compared to innocent interview situations (18.4%). Unexpectedly, approximately an equal number of suspects reported having denied truthfully (39.8%) and falsely (40.2%) at least once in their lifetime. The main reasons reported for these statement types were that evidence seemed to indicate guilt (true confessions), suspects desired to end the uncomfortable interview situation or protect the real perpetrator/another person (false confessions), evidence seemed weak (false denials), suspects felt innocent (true denials), they desired to protect themselves (silence while being interviewed when guilty), and they followed their attorneys’ advice (silence while being interviewed when innocent). Findings are discussed in the context of the police and psychological research and practice.

Discussion

The present study examined the lifetime prevalences, conditional probabilities, and reasons for suspects’ confessions, denials, and remaining silent in police interviews. We will interpret our findings on the three statement behaviors comprehensively and then discuss their scientific and practical implications.

First, as expected, more suspects reported having confessed at least once in their lifetime in guilty interview situations compared to innocent interview situations. The prevalence of false confessions among our sample was 4.1% and slightly below the range between 5.9 and 24% presented in Table 1 for inmates, offenders and forensic patients. However, the corresponding credibility interval in this study includes this range (95% CI [2.3, 6.9]. The false confessions reported here refer to different types of offenses (theft, fraud, assault, robbery, property damage, drug offenses, sexual offenses). The main reported motives for false confessions were to protect the real perpetrator/another person and a desire to end the uncomfortable interview situation. Ending the interview because of an aversive situation can be assigned to the type of coercive false confessions (e.g., Kassin and Wrightsman 1985), and researchers have already given recommendations on how to decrease the risk of this (e.g., Kassin et al. 2010). In contrast, protecting another person belongs to the type of voluntary false confessions (e.g., Kassin and Wrightsman 1985). Whereas this is a frequently reported reason for false confessions, we know of no literature focusing on how interviewers can detect and minimize voluntary false confessions in order to protect another person. This could be a line for future research.

The lifetime prevalence of true confessions in this study (64%) falls in between the wide range of the four self-report studies examining true confessions (28 to 92%; see Table 1). Also, the true confessions reported here refer to different types of offenses, with most being for theft, assault, and drug offenses. The most frequently mentioned reasons for true confessions were that the evidence seemed to indicate guilt and the suspect’s feeling of guilt. This result is in line with a review by Moston and Engelberg (2011) showing that the strength of evidence is a major predictor for a confession, and the meta-analysis by Houston et al. (2014) who found that true confessions were associated with the suspects’ emotional reactions to the interview and their perceptions of the evidence and their guilt. However, suspects also frequently reported the hope to get a lower sentence as a reason for true confessions. This was also a frequently mentioned reason for false confessions. It indicates that suspects consider the perceived consequences when contemplating confessing (on the effect of consequences on confession decisions, see Madon et al. 2012).

Second, as expected, more suspects reported having remained silent at least once in their lifetime in guilty interview situations (58%) compared to innocent interview situations (18%). To the best of our knowledge, this is the first study to examine the reasons for being silent in guilty and innocent interview situations from the suspect’s perspective. Here, we want to highlight two results: First, the vast majority of suspects reported having remained silent at least once in their lifetime in guilty interview situations because they wanted to protect themselves against misuse of any statement they made. Furthermore, numerous suspects reported that they remained silent at least once in their lifetime in innocent interview situations because they generally do not make statements to the police. This reflects a rather critical picture of the police, and further research on this needs to follow. Second, the attorney’s advice to remain silent was a frequently reported reason for being silent at least once in a lifetime in both guilty and innocent interview situations. Future research could involve attorneys in order to understand the considerations and decisions of suspects and the interview interactions in more detail.

The lifetime prevalence of false denials (40%) was about the same as that for true denials (40%). This result was unexpected and contradicts the findings by Volbert et al. (2019) indicating a higher prevalence of true denials than false denials among forensic patients. Further research should examine this in more detail. However, both studies show that suspects frequently report true denials. Kassin et al. (2003) have argued that a true denial puts innocent suspects at risk: They found that interviewers tried hardest to obtain a confession when they presumed the suspect’s guilt, but the suspect was in fact innocent. From a suspect’s perspective, being innocent and truly denying an accusation can lead to facing an interviewer aiming to coerce a confession. Coercive and accusatorial interviewing, in turn, raises the risk of false confessions (e.g., Meissner et al. 2014). From the police perspective, “truly denying” is a highly challenging statement behavior. The rationale of this is the cognitive mindset of an interviewer: they may launch a suspect interview when they assume that the suspect is guilty. In this mindset, they may assess denials which do not contain conclusive exculpatory information as a sign of the suspect’s guilt. A pitfall here is that they need to distinguish true from false denials, but the ability of interviewers and humans in general to detect deception is poor (e.g., Bond and DePaulo (2006) found an overall accuracy rate of 54%). Probably the only reliable way to assess the validity of denials is by comparing statements with other evidence (e.g., Vredeveldt et al. 2014), but this becomes impossible if corroborating as well as exculpatory evidence is lacking. Suspects most frequently explained false denying in reported guilty interview situations with seemingly unclear evidence, the hope of not being convicted, and the hope of being released from custody. We believe it is fair to assume that these reasons relate to the strength of the evidence. Taking into account the most frequently reported reason for true confessions (evidence seemingly indicating guilt), this indicates the significant role of evidence from the suspects’ perspective.

This study also shows that the suspects made different statements in police interviews, and specific statement behaviors cannot be attributed solely to innocence or to guilt. Taking the reported guilt or innocence as a starting point, we calculated conditional probabilities that allow descriptions of which types of statements the suspects reported most probably for guilty or innocent interviews. Considering the reported guilty interview situations, the probability was highest for remaining silent (40%), followed by true confessions (36%), and false denial (24%). In contrast, for reported innocent interview situations, the probability was highest for true denial (60%), followed by remaining silent (36%), and eventually false confessions (4%). This finding is highly relevant to investigative practice: First, it shows that suspects—when they make a statement—most commonly make true statements (i.e., true confessions and true denials). Second, from a police perspective, the diversity of statement behaviors in innocent and guilty suspects shows the need to conduct suspect interviews in an open-ended manner. Interviewers’ open-ended mindset is at the core of investigating interviewing and is implemented, for example, in the PEACE model (e.g., Bull 2019). The results of the present study provide support for the international effort to introduce and implement investigative interviewing (e.g., European Committee for the Prevention of Torture and Inhuman or Degrading Treatment or Punishment 2019), and generally an open-minded interview approach (Principles on Effective Interviewing for Investigations and Information Gathering 2021).

Finally, for innocent interview situations, the probability that suspects will waive their right to remain silent and deny is higher than that of remaining silent (at least once in their lifetime). In line with experimental findings (Kassin and Norwick 2004), Kassin (2005) has assumed that innocent suspects waive their right to remain silent because they may (a) trust in the fairness of the justice and legal system and expect that their innocence will be believed if they “just tell it like it happened,” and (b) believe that interviewers will be able to read their thoughts and emotions and hence will “see their innocence.” In the present study, the most and exclusive reason for denying in innocent interview situations was the suspects’ explanation “I was innocent.” This underpins Kassin (2005) claim that “innocents put innocence at risk,” because waiving the right to remain silent is an essential antecedent for false confessions. Scherr et al. (2016) also found that suspects’ willingness to waive their rights and deny an offense increased with the strength of their just-world beliefs. However, from a police interviewer’s perspective, the situation is different: Interviewers may conduct suspect interviews when they presume some degree of guilt. Thus, they may assume that the suspect is guilty, assess remaining silent and denying (when no other evidence for cross-checking is available) as an indicator for their guilt, and aim to overcome this and collect confessions. Differently put, remaining silent or denying when being innocent can lead to a risky interview situation with biased perceptions and assessments and coercive interviewing by the police interviewer. This, in turn, can result in false confessions by suspects.

Limitations

This study is based on retrospective self-reports that have some methodological limitations (e.g., social desirability, cognitive biases, remembering specific events out of multiple similar events, estimated frequencies of events), and we had no information with which to validate the participants’ self-reports (e.g., about their status of being guilty or innocent). These limitations hold true when surveying inmates (e.g., Gudjonsson and Sigurdsson 1994) but also police investigators (e.g., Kassin et al. 2007). Nevertheless, suspects are clearly central to suspect interviews, and their perspectives provide crucial information on them. Second, the current nonrepresentative sample limits the generalizability of the results (e.g., all participants were from one German federal state, German-speaking, without extensive cognitive disabilities). Third, the number of false confessions was small, and this limits the precision of the findings on the reasons for confessing when innocent. Future studies should remedy these limitations by including (a) more and a wider range of participants (e.g., persons from different German federal states, non-German speakers, suspects with cognitive disabilities), and (b) more information about the interview context (e.g., duration, location, persons present) and the personal characteristics of the suspects (e.g., mental health).