The Formation of Judicial Conviction in Indonesia: Convergence of Legal Norms and Empirical Reasoning in Criminal Proof

Source abstract

The Indonesian criminal procedure system adheres to the negatief wettelijk bewijstheorie, requiring judges to base convictions on at least two lawful pieces of evidence supported by judicial conviction. While formal legal norms set minimum evidentiary requirements, empirical judicial practices reveal that judges also consider non-formal factors in shaping their convictions. Current legal doctrines lack clarity on how such non-legal factors influence the formation of judicial conviction, and how this aligns with the principle of legality. This study investigates the convergence between normative evidentiary standards and empirical judicial reasoning in the formation of judicial conviction, including comparative insights with the "beyond a reasonable doubt" standard in common law. Empirical research involving 50 Indonesian judges shows that sentence is often shaped not only by formal evidence but also by defendant behavior, witness demeanor, background narratives, and academic literature. Although such considerations support material truth-seeking, they introduce risks of subjectivity without clear safeguards. This study integrates doctrinal, empirical, and comparative analyses to reveal the multi-layered process of judicial conviction formation in Indonesia. It proposes a conceptual framework that bridges legal rules with empirical practices. The findings call for the development of judicial guidelines, enhanced forensic psychology training for judges, and partial reform of the Indonesian Code of Criminal Procedure (KUHAP) to ensure proportional certainty without undermining legal formalism.