Preventive detention under law 15,272/2025

: abstract gravity, genetic data collection and defence strategies in custody hearings

Abstract

Law no. 15,272/2025 reshapes key aspects of the Brazilian legal regime on preventive detention, particularly by introducing statutory “circumstances that recommend” the conversion of arrest in flagrante into pre-trial custody (Code of Criminal Procedure, art. 310, § 5), making it mandatory for judges to examine such circumstances and the statutory criteria of dangerousness (art. 310, § 6), creating art. 310-A on the collection of genetic profiles during custody hearings, and expressly forbidding abstract gravity of the offence as a sufficient ground for detention (art. 312, § 4). This paper aims, from a constitutionally oriented perspective and in dialogue with the case law of the Brazilian Supreme Court, the Superior Court of Justice and the Inter-American Court of Human Rights, to assess the guarantees and punitive risks of the new legal framework, with emphasis on the role of the Public Defender’s Office in custody hearings. It discusses (i) the new normative design of preventive detention, (ii) the legislative consolidation of the prohibition of abstract gravity, (iii) the constitutional challenges posed by compulsory biological sampling and (iv) a practical roadmap for defence strategies in custody hearings. The central claim is that Law 15,272/2025 is only legitimate if construed as a tool to reinforce the exceptional nature of pre-trial detention, rather than as a shortcut for expanding provisional imprisonment.