Are domestic war crimes trials biased?

Abstract Fairness of domestic war crimes trials matters for promoting justice and peace. Scholars have studied public perceptions of war crimes trials to assess their fairness, but little is known about whether post-conflict states conduct them fairly. Bias, as a matter of procedural fairness, can manifest as a tendency to favour certain groups over others. Leveraging the theories of judicial decisionmaking, this article investigates two types of bias. The first is in-group bias, which is associated with protection of in-group members and punishment of out-group members. The second is conflict actor bias, which is associated with deflecting responsibility for wrongdoing from state agents to non-state agents of violence. We test for bias in domestic war crimes trials in Serbia with statistical modelling and quantitative text analysis of judicial decisions delivered to Serb and non-Serb defendants (1999–2019). While we do not find evidence of ethnic bias, our results indicate conflict actor bias. Serb paramilitaries received harsher sentences than Serb state agents of violence. Furthermore, we observe bias in the textual content of judgements. Judges depict violence committed by paramilitaries more extensively and graphically than violence by state actors. By revealing these judicial strategies, we demonstrate how a state can use domestic war crimes trials to diminish state wrongdoing and attribute the responsibility for violence to paramilitaries. The conflict actor bias we identify shows how deniability of accountability operates after conflict, complementing existing explanations of states’ collusion with paramilitaries before and during conflict.