Reconstructing French Criminal Justice: Procedural Codification, Criminal Trial Reform and the Constitutional Limits of Penal Efficiency

French criminal law is undergoing a significant process of institutional and procedural transformation, driven by the need to improve the administration of criminal justice, reduce delays in adjudication, strengthen victim participation, modernise investigative techniques, and preserve the fundamental guarantees of a fair trial. These developments raise a central question: to what extent can procedural efficiency be increased without weakening the legality, impartiality, and legitimacy of criminal adjudication? This article examines contemporary reforms in French criminal justice through three interconnected developments: the recodification of the Code of Criminal Procedure under Ordinance No. 2025-1091 of 19 November 2025; the enactment of Law No. 2026-651 of 23 July 2026 on criminal justice and respect for victims; and the continuing expansion of investigative powers in response to complex and organised criminality. It evaluates the legal and institutional implications of these developments through the principles of legality, proportionality, the presumption of innocence, adversarial proceedings, effective defence, and judicial control. The article argues that procedural modernisation should not be assessed solely by its capacity to increase the number or speed of criminal convictions. Its legitimacy depends on whether procedural simplification is accompanied by effective safeguards, transparent judicial reasoning, adequate legal assistance, and meaningful remedies for unlawful state action. A sustainable model of criminal justice must therefore treat efficiency and procedural fairness as mutually reinforcing requirements rather than competing objectives.