Governança da prova e lavratura do auto de prisão em flagrante por alcoolemia: evidências empíricas da Operação Lei Seca no Estado do Rio de Janeiro

The application of Article 306 of the Brazilian Traffic Code involves multiple mechanisms for the production, incorporation, and use of evidence, whose relationship with the outcomes of criminal proceedings remains underexplored empirically. This study investigated the association between forensic examination status at the Institute of Legal Medicine and arrest in flagrante delicto in criminal drunk-driving cases recorded by the Rio de Janeiro State Operação Lei Seca (Drunk Driving Enforcement Program). This retrospective observational study was based on administrative microdata from 2025, comprising an analytical sample of 103 cases involving drivers with breath alcohol concentrations equal to or greater than 0.34 mg/L. Descriptive analyses, association tests, and logistic regression were performed. The results showed a statistically significant association between forensic examination status and arrest in flagrante delicto, whereas breath alcohol concentration was not significantly associated with this outcome in the adjusted model. Non-performance of the forensic examination was associated with higher estimated odds of arrest in flagrante delicto (OR = 4,75; IC 95%: 2,01–11,19), although the study design does not allow a causal relationship between these events to be established. The findings reveal different institutional pathways in the formation and use of the body of evidence and support the usefulness of evidentiary governance as an analytical category for examining institutional variability in the composition of evidence in the application of Article 306 of the Brazilian Traffic Code.