THE EXCEPTIONAL ADMISSIBILITY OF ILLICIT EVIDENCE IN FAVOR OF THE DEFENDANT IN BRAZILIAN CRIMINAL PROCEDURE: PROPORTIONALITY, CONSTITUTIONAL LIMITS AND LEGAL CERTAINTY

Abstract

This article analyzes the exceptional admissibility of unlawfully obtained evidence when invoked in favor of the defendant in Brazilian criminal procedure. The research starts from the constitutional exclusionary rule established in article 5, item LVI, of the Brazilian Constitution, and from article 157 of the Code of Criminal Procedure, in order to examine to what extent the right to defense, the presumption of innocence, the favor rei principle and proportionality may justify a narrow defense-oriented exception. The method is bibliographical and documentary, based on criminal procedure scholarship and on precedents of the Brazilian Supreme Federal Court concerning derivative illicit evidence, bank secrecy, the right to silence and judicial impartiality. The analysis corrects overly broad readings of case law, emphasizing that the Supreme Court has not established a general authorization for the use of illicit evidence pro reo, but rather adopts case-specific reasoning subject to concrete judicial justification. The article concludes that defensive illicit evidence may only be admitted in exceptional circumstances, when there is direct defensive relevance, indispensability, subsidiarity, authenticity, chain-of-custody preservation, effective adversarial scrutiny, absence of abusive provocation and prohibition of its use to expand the accusation or worsen the defendant’s legal position.