UC Irvine

Informants are an integral part of the American criminal justice system. However, relatively little research has been done on nearly all aspects of informant use, from how they are recruited and how they reach agreements to cooperate with law enforcement to how jurors evaluate their testimony in court. The present study focuses on this last area – juror perceptions of informants who testify. The limited research that exists on this topic has presented troubling conclusions: jurors may not be appropriately responsive to cues that could signal informant unreliability. In particular, jurors may fail to account for and properly weigh evidence that an informant is testifying for an incentive (such as a reduced prison sentence) when reaching a verdict. However, thus far, studies in this area have some limitations in case type, materials used, and statistical power. The objective of the current study is to advance in each of these areas and provide new evidence about the impact of juror perceptions of informant incentives. This study used a novel fact pattern, video stimuli manipulations, and a sample of 886 online participants to test the impact of informant incentives on juror judgments. It featured four conditions that vary the nature and size of the incentive reported by a jailhouse informant (i.e., no incentive, a vague leniency incentive, and small and large sentence reduction incentives), plus a control condition with no informant testimony. The results speak to the conflicted literature on this topic – finding a significant impact of incentive presence on verdicts. Participants who observed an incentivized informant rated him as less credible and were less likely to convict the defendant based on his testimony – compared to participants who viewed an otherwise identical non-incentivized informant. However, participants’ verdicts in this study were not sensitive to changes in the size of an informant’s incentive, showing no significant difference in conviction rates when the incentive was large (10 years off of a 20-year sentence) compared to small (1 year off of a 20-year sentence). This study also included a test of a novel hope-for-leniency condition, which prompted verdict responses most similar to that of the small incentive condition. These results suggest that jurors may be more capable than previously thought at accounting for informant incentives in reaching a verdict. It also suggests that reforms that aim to preserve evidence of jailhouse informant incentives and ensure that such information is able to reach a jury at trial have potential to meaningfully influence verdict outcomes.