The presented fundamental research is devoted to a comprehensive theoretical and practical analysis of the mechanisms for ensuring the procedural rights of individuals involved in the orbit of criminal prosecution in the status of suspects and accused within the legal system of the Republic of Kazakhstan. In the context of the phased implementation of a three-tier model of criminal justice, the reform of national legislation, and the total digitalization of legal proceedings, the issues of strict observance of constitutional guarantees of the individual acquire existential significance for building a state based on the rule of law. The article examines in detail the key systemic defects and collisions in the implementation of the right to qualified defense, the excessive use of repressive preventive measures, as well as barriers to accessing fair justice. Special attention is paid to a deep comparative legal analysis of the large-scale changes expected in 2025–2026 in the procedural legislation of neighboring states (the Russian Federation), which allows identifying strategic vectors for the development of regional legal doctrine and proposing scientifically sound ways to implement best practices into the Criminal Procedure Code of the Republic of Kazakhstan (CPC RK). Conceptual and systemic proposals are formulated for improving procedural institutions in order to ensure genuine, rather than declarative, adversarial proceedings and absolute equality of the parties in the criminal process.