Confession evidence results in more true and false guilty pleas than eyewitness evidence

Objectives This study examines how confession (versus eyewitness) evidence and guilt status impacts mock defendants’ plea decisions and perceptions of their probability of conviction (PoC) and the strength of evidence (SoE), key elements of the shadow-of-the-trial model. Methods In a simulated mock-theft scenario, adult participants ( n = 239) were randomly assigned to a guilt status (guilty/innocent) and evidence-type (confession/eyewitness) condition. They were offered a plea, and perceptions of PoC and SoE were measured. Results As predicted, confession evidence led to higher rates of pleas than eyewitness evidence. Guilty participants were also more likely to accept the plea than innocent participants. However, evidence type did not impact perceptions of PoC or SoE, though guilt status did. Conclusions Our findings empirically support the impact that confessions—true or false—and guilt status have on plea decision-making. We discuss implications of these results for the shadow-of-the-trial model and the cumulative-disadvantage framework.