Order of evidence presentation affects the evaluation and the integration of evidence in mock criminal cases. In this study, we aimed to determine whether the order in which incriminating and exonerating evidence is presented influences cognitive dissonance and subsequent display of confirmation bias. Law students (N ¼ 407) were presented with a murder case vignette, followed by incriminating and exonerating evidence in various orders. Contrary to a predicted primacy effect (i.e. early evidence being most influential), a recency effect (i.e. late evidence being most influential) was observed in ratings of likelihood of the suspect's guilt. The cognitive dissonance ratings and conviction rates were not affected by the order of evidence presentation. The effects of evidence presentation order may be limited to specific aspects of legal decisions. However, there is a need to replicate the results using procedures and samples that are more representative of real-life criminal law trials.

Having to explain a decision has often been found to have a positive effect on the quality of a decision. We aimed to determine whether different accountability requirements for judges (i.e., having to justify their decision or having to explicate their decision) affect evidence use. Those requirements were compared to instructions based on the falsification principle and a control condition. Participants (N ¼ 173) decided on the defendant's guilt in a murder case vignette and explained their decision according to the instructions. The explication and falsification (but not the justification) instructions increased the use of exonerating evidence. There was no significant difference between the groups in guilt perception. The use of exonerating evidence was a significant positive predictor of acquittal rates. The implications for the different forms of instructions in practice are positive, but suggest a difference between the evidence considered and the evidence used to account for the decision.

Abstract. Are expert witnesses biased by the side (defense vs. prosecution) that hires them? We examined this issue by having students act as expert witnesses in evaluating interviews in a child sexual abuse case (Experiment 1, N = 143) and tested the value of an instruction to counteract such allegiance effects. The intervention concerned an instruction to consider arguments both for and against the given hypothesis (i.e., two-sided instructions; Experiment 2, N = 139). In Experiment 3 ( N = 123), we additionally provided participants with three different scenarios. Participants received a case file regarding a case of alleged sexual abuse. With the file, participants received an appointment letter emphasizing elements of the file that questioned (defense) or supported (prosecution) the veracity of the accusation. Participants displayed allegiance bias (Experiments 1–3), but two-sided instructions were not successful in eliminating allegiance bias (Experiments 2 and 3). The findings underscore the importance of legal safeguards in expert witness work.