The impact of variations in confession evidence on jurors’ decision-making

Kelsey S. Henderson, Portland State University
Lora M. Levett, University of Florida

The reliability of a confession partially depends on the interrogation methods used and the confession’s content. Confronting suspects with evidence gives a suspect knowledge of nonpublic details, increasing the likelihood of a false confession (Gudjonsson & Pearse, 2011; Leo, 2009), and makes the confession harder to judge as more or less reliable. That is, if a confession is consistent with case facts but details of the crime were communicated to the suspect during interrogation, it is difficult to judge whether the confession is a product of the suspect’s knowledge of the crime or the details that were communicated during the interrogation. The objective of this article was to examine whether jurors consider the interrogation technique and source of consistent knowledge in judging the reliability of confession evidence. In 2 studies, participants read a trial summary in which the defendant’s confession was consistent versus inconsistent with case facts and evidence was withheld versus disclosed during the interrogation. In Study 2, we also examined for moderating effects of need for cognition (NC). Overall, participants were attuned to confession– case facts consistency in making decisions; furthermore, in Study 2, this effect interacted with evidence disclosure on a number of measures. If the confession was consistent, participants rated the strength of evidence and reliability of the confession higher, and impression of the interrogation more positively, when evidence was withheld during the interrogation rather than disclosed. NC did not moderate these effects. Overall, findings suggest participants are somewhat sensitive to variations in confession evidence.

confessions, jury decision making, interrogations, strategic use of evidence, need for cognition

“Confessions, repeated denials, assertions of innocence, and exculpatory and inculpatory statements are all products of an interrogation. If a suspect has waived their Miranda rights (Miranda v. Arizona, 1966), these statements can be used at trial. One concern is if information in a confession did not originate with the suspect, but was disclosed during the interrogation. Sharing evidence in an interrogation could give an innocent suspect knowledge of nonpublic details of the crime, increasing the likelihood that should the suspect confess, he or she will incorporate those details in the false confession. One out of four individuals exonerated through exculpatory DNA evidence falsely confessed. False confessions can be full of inaccurate details and inconsistencies, which theoretically could help fact finders spot a false confession. However, many false confessions contain accurate, nonpublic details known only to the perpetrator. These details are likely learned through the interrogation and incorporated into the false confession.” (p. 245)

“Confronting suspects with evidence at the beginning of an interrogation is a commonplace occurrence. […] If the information included in a confession is consistent with crime facts, jurors are more likely to judge the confession as credible compared to if the confession is inconsistent with crime facts. However, a confession that is consistent with crime facts is not necessarily a reliable indicator of accuracy given that providing details during the interrogation can artificially inflate the consistency of a suspect’s confession.” (p. 245)

“The reliability of a confession should be at least partially judged by the content of the confession (i.e., the consistency of the confession with the facts of the case) combined with the techniques used during the interrogation. In these studies, we examined if participants are sensitive to variations in the quality of confession evidence, defined by the consistency of the confession information with the details of the crime and the evidence disclosure strategy used in interrogation. In Study 1, we examined participants’ abilities to examine the content of a confession (consistent vs. inconsistent with case facts) and the evidence disclosure technique used during the interrogation (evidence disclosed vs. evidence withheld). In Study 2, we examined if need for cognition moderated participants’ sensitivity to these variations.” (p. 246)

“Research has demonstrated that jurors weigh confession evidence heavily. Confession evidence affects verdict decisions even if that confession is stricken from the record, and regardless of the coerciveness of the interrogation. Research examining jurors’ sensitivity to variations in interrogation and confession evidence is mixed.”(p. 246)

“The consistency between content in a confession and crime facts can help indicate whether the confession is reliable or unreliable evidence. There is some evidence to suggest that jurors are sensitive to variations based on consistency. […] A consistent confession is not necessarily an indicator of accuracy. Instead, it is an indicator that one should assess whether evidentiary information was shared with the suspect during the interrogation prior to the suspect’s confession. In examining the reliability of the confession, one must consider both the content of the confession and the techniques used during the interrogation and whether they could have contaminated the confession evidence.” (p. 246)

“Our research explores one key distinction between accusatorial and information-gathering interrogation models—the presentation of evidence. Accusatorial interrogations are common in the United States. […] The accusatorial model involves two phases: the interview (to determine if the individual is a suspect to be formally interrogated) and the formal interrogation. During the confrontation stage of the formal interrogation, the officer confronts the suspect with real or falsified evidence of their guilt. Central to the research question of this article, this confrontation can result in relaying information about the crime to the suspect. Importantly, disclosing of evidentiary information can be either intentional or by accident, but research suggests it is a frequent occurrence. […] Examining common strategies of accusatorial interrogations demonstrates that the actions of interrogators can lead to evidence contamination or sharing evidence of the crime with the suspect.” (pp. 246–247)

“Information-gathering interviews are more common outside of the United States. […] This model focuses on building rapport and stresses the importance of honesty, explaining the offense, and asking the suspect to give their version of events. […] One clear difference between the accusatorial model and the information-gathering model is the method in which information (i.e., evidence) is preserved, shared, and utilized during the interrogation. Accusatorial interrogations are more likely to involve disclosing evidence at the beginning of an interrogation, making the suspect aware of the incriminating evidence against them. In contrast, in information-gathering interviews and in techniques for lie detection like the Strategic Use of Evidence technique, information is withheld until after suspects have given their version of events, and may not be disclosed at all” (pp. 246–247)

“By withholding evidence, the interrogator should be able to use the consistency or inconsistency between individuals’ statements and case facts to separate liars from truth tellers, thereby lowering the risk of a false confession. […] The goal of withholding evidence is to increase deception detection in the interrogation room while simultaneously decreasing the likelihood of evidence contamination. […] Withholding information in the interrogation room should also increase the likelihood independent fact finders could use the characteristics of the confession to weigh the confession appropriately. […] In these studies, we examined jurors’ sensitivity to variations in confession evidence by focusing on these aspects of confession–case facts consistency and evidence disclosure technique.” (p. 247)

Study 1:

“Participants were 356 jury-eligible U.S. citizens drawn from Amazon’s Mechanical Turk (MTurk) worker pool. All participants were over the age of 18 and a U.S. citizen (statutory requirements for jury service). […] To manipulate the consistency of the confession with the case facts, we manipulated the content of the case facts and the confession. In half of the conditions, participants read a case in which the victim was stabbed one–two times and was incredibly short (lower severity); in the other half, participants read a case in which the victim was stabbed 38 times and was incredibly tall (higher severity). […] The study used a 2 (Case Facts: low vs. high severity) X 2 (Confession: low vs. high severity) X 2 (Evidence Disclosure: disclosed v. withheld) between-subjects factorial design.” (p. 247) The conditions included confessions of a defendant according to the presented story variation.

“In evidence-disclosed conditions, the officer testified that they followed the Reid model and that one common technique in this model involved confronting the suspect with evidence and case information at the beginning of the interrogation. […] When asked what evidence he confronted the defendant with, the officer testified that he shared “some details” related to the victim and the murder.” (p. 248)

“In evidence-withheld conditions, the officer testified that they used the Strategic Use of Evidence technique and that this involves withholding evidence from the suspect and using it later if necessary.” (p. 248)

“Overall, in this study, participants were sensitive to consistency between the confession and case facts. Participants rated the defendant’s probability of guilt, strength of evidence, and reliability of the confession higher, and their impression of the interrogation more positively, in consistent conditions compared to inconsistent. We also found that whether evidence was withheld or disclosed affected impressions of the interrogation. Participants in evidence-withheld conditions had more positive impressions of the interrogation than those in evidence-disclosed conditions. Importantly, the interaction between confession– case facts consistency and evidence disclosure was not significant on most dependent measures; this would have indicated that participants were sensitive to where confession details could have originated.” (p. 251)

“In this study, participants did not largely consider the potential source of information in evaluating the consistency of the confession. Instead, we found that participants considered consistency in their evaluations of evidence, and some support for the notion that participants consider evidence-disclosure techniques in their decision making. However, we did not see effects of our independent variables on verdict, indicating that participants’ evaluations of evidence did not ultimately carry over to the dichotomous verdict decision.” (p. 251)

“One individual factor that might influence jurors’ motivation to process information systematically is need for cognition. Need for cognition (NC) is defined as individual differences in one’s tendency to engage in and enjoy thinking. It can be examined as a moderating variable to help determine which route to persuasion individuals use. High NC individuals tend to employ more cognitive thought and evaluate the merits of information systematically more than low-NC individuals, whereas, low-NC individuals tend to be more influenced by superfluous cues like heuristics that are not necessarily relevant to the message than high-NC individuals (e.g., attractiveness of an endorser). ” (p. 251)

Study 2:

“Recall that in Study 1, participants were sensitive to variations in confession– case facts consistency, but largely did not perceive the consistency between confession evidence and case facts differently based on whether evidence was disclosed or withheld during the interrogation. It is possible that participants higher in NC (vs. low) would make the connection between evidence disclosure and variations in confession evidence (i.e., NC may moderate participants’ sensitivities to variations in confession evidence).” (p. 252)

“Participants were 1,005 jury-eligible U.S. citizens drawn from Amazon’s MTurk worker pool. Participants were ineligible to complete study 2 if they had completed Study 1. […] Similar to Study 1, we manipulated the consistency of the case facts with the confession by varying the case facts and confession evidence while simultaneously counterbalancing for evidence severity. This study used a 2 (Case Facts: low vs. high severity) X 2 (Confession: low vs. high severity) X 2 (Evidence Disclosure: disclosed v. withheld) between-subjects factorial design. Participants were randomly assigned to one of the eight conditions.” (p. 252)

“In this study, participants were more likely to convict in consistent confession– case facts conditions than inconsistent conditions. Additionally, we found main effects of evidence disclosure and NC on participants’ verdicts; participants were more likely to convict if evidence was withheld compared to disclosed, and participants higher in NC were less likely to convict than those lower in NC. Consistent with Study 1, there was a main effect of confession– case facts consistency on probability of guilt ratings; participants in consistent conditions averaged probability of guilt ratings 20.24 points higher than those in inconsistent conditions.” (pp. 255–256)

“We found the expected interaction effect between confession–case facts consistency and evidence disclosure on participants’ ratings of the strength of evidence, reliability of the confession, and impression of the interrogation. Participants who heard a consistent confession in evidence-withheld conditions rated the strength of evidence and reliability of the confession higher than those evidence-disclosed conditions.” (p. 256)

“In these studies, we explored the effect of confession–case facts consistency and evidence disclosure on participants’ evaluations of confession evidence. Consistent with past research, we found that confession–case facts consistency influenced participants’ verdicts (in Study 2). Participants were more likely to convict when the confession details and case facts were consistent compared to inconsistent. While there was also a main effect of evidence disclosure on participants’ verdicts in Study 2, this effect did not interact with confession–case facts consistency to affect verdict in either study.” (pp. 256–257)

“Overall, participants are using consistency as a cue to accuracy, but this comes with concern, as they did not consider the possibility of whether the confession information was the result of interrogation techniques in assigning culpability or rendering verdicts. Other research has shown that jurors can be sensitive to the origin of confession information in rendering a verdict; however, our studies did not show sensitivity on the verdict measure.” (p. 257)

“In Study 2, using a different guideline to calculate our a priori sample size, we found significant effects of the interaction between confession–case facts consistency and evidence disclosure on many dependent measures, indicating that perhaps more power is needed to see the effect of the interaction. […] We found that participants viewed a consistent confession obtained using best practices (evidence withheld) as more reliable compared to a consistent confession obtained using more traditional techniques (evidence disclosed). Participants were also sensitive to the benefits of withholding evidence during the interrogation in their overall impression of the interrogation ratings.” (p. 257)

“Accusatorial interrogations, common to the United States, increase the risk of a false confession. Research suggesting jurors are not sensitive to coercive interrogation techniques in their evaluation of confession evidence nor their verdict decisions, highlight the dangers of these techniques, and that confessions elicited from them should be viewed with caution. These data speak to that concern on the key dependent variable—verdict. These data further contribute to that body of research. Participants did not differ in their conviction rates between a suspect whose confession was consistent but evidence withheld, and one whose confession was consistent but evidence disclosed. That is, jurors were not sensitive to evidence contamination in rendering verdicts.” (pp. 257–258)

“However, participants were sensitive to evidence contamination on most of our other dependent variables—strength of evidence, reliability of the confession, impression of the interrogation (Study 2), and ratings of the defendant (Study 1). From a practice perspective, this suggests participants are cognizant of threats to the reliability of confession evidence, and that translates to the evidentiary weight assigned and evaluations of the interrogation and defendant.” (p. 258)

“These data suggest jurors are somewhat attuned to threats to reliability of the confession evidence, and look to the techniques used to obtain that admission in their decision making. And while this did not translate to ultimate verdicts in our study, jurors’ assigning more weight to a consistent confession, where evidentiary information was not shared, is promising from a practice standpoint.” (p. 258)

“As suggested [by other researchers], withholding evidence during the interrogation allowed jurors to critically evaluate the content of the confession evidence. However, given that this evaluation did not translate to participants’ decisions on verdict, policies in the interrogation room should follow best practices regarding preserving case information, ensuring that suspects’ statements are not contaminated.” (p. 258)

“These studies are not without limitations. First, although the MTurk sample is arguably more ecologically valid than an undergraduate student sample, participants were participating online, which limits the overall ecological validity of the paradigm. We were also unable to control whether MTurk participants completed the study without aid from others, although they were instructed to do so.” (p. 258)

“We did not inquire about prior interactions with the police or a criminal record, which may have affected participants’ decisions. We also did not include questions asking participants about their perceptions of the purpose of the studies. While we minimized the chances participants would guess the manipulations of our study by presenting them within the context of the full trial, it is a limitation that we do not have data to support that assertion.” (p. 258)

“Second, the stimulus used in these two studies was the same; future research should attempt to replicate and extend the effects using a different stimulus to ensure generalizability across many types of cases. […] Future research could manipulate the strength of the case more directly to assess whether the strength of the evidence interacts with the manipulations in this study to affect jurors’ decisions.” (p. 258)

“Another shortcoming of our stimulus is that it was a written trial rather than a videotaped stimulus. While we presented a full trial as to not focus participants on just confession evidence (thereby giving away the purpose of the study), a more ecologically valid stimulus would have presented the full videotaped trial.” (p. 258)

“Third, it is possible that other factors may influence how well jurors process information about the consistency of confession evidence and case facts (and the origin of the consistent or inconsistent information). […] Future research could examine the effectiveness of expert testimony or other educative mechanisms (educational cross examination, jury instructions) in educating jurors about the consistency of confession evidence and case facts and the origins of that information.” (p. 258)

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