Evaluation of Informant Witnesses Testimony: Why are They so Believable?

Author: Alina Marino
Major: Psychology, Criminal Justice
Approved: Spring 2019
Status: Completed

The Innocence Project (2019), which tracks DNA exoneration cases, indicates that approximately 15% of their cases involve an unreliable jailhouse informant, one of five leading causes of wrongful conviction. The current study was designed to evaluate existing research and extend understanding of how informant witnesses are perceived. An informant witness is a non-expert witness who is generally incentivized to provide testimony (Roth, 2016). Research regarding informants is limited, only one previous study has examined perceptions of both jailhouse informants and accomplice witnesses (Neuschatz et al., 2008). The current study aimed to assess whether accomplice witnesses and jailhouse informants are evaluated equally. Participants read a trial transcript of a murder case in which the type of informant witness (jailhouse informant or accomplice witness) was varied. In additions, the crime the informant had previously committed (armed robbery or fraud) was also varied to see if prior criminal history effects juror decision-making. Participants were also asked to make judgements about the informant. There was no effect of informant or crime type on verdict decisions, however, the jailhouse informant was rated as significantly more honest than the accomplice witness.