The authors examined the issues of ensuring the rights and interests of individuals in the field of criminal proceedings both in the Republic of Kazakhstan and in other countries of the Commonwealth of Independent States (hereinafter referred to as the CIS). The protection of fundamental human rights and freedoms is a universal principle, since these values are subject to priority protection in all spheres of public and state life. Man, his rights and freedoms occupy a central place and dominate over all other humanitarian values. The protection of human rights and freedoms acquires particular socio-political importance in the field of criminal proceedings, that is, where law enforcement agencies have the capabilities of state coercion, allowing them to invade the sphere of personal interests and significantly limit them. The legal policy of the Republic of Kazakhstan has already solved a number of important tasks to improve criminal procedural legislation. Since 2015, a new Code of Criminal Procedure (hereinafter referred to as the Code of Criminal Procedure) has been in force, which has introduced many innovations to simplify, speed up, reduce investigative and judicial procedures, streamline and differentiate the procedural powers of persons conducting criminal proceedings, strengthen the status of the defense party, as well as ensure the rights and legitimate interests of all persons participating in criminal proceedings. In addition, new legal institutions, proceedings and norms have been introduced that bring the criminal process closer to successfully tested models for the investigation of criminal offenses and the administration of justice. Along with this, most legislative decisions, when tested by law enforcement practice, showed their weak (insufficient) effectiveness, inconsistency with the established provisions of the theory of criminal procedure law, the absence in law enforcement practice and in the theory of criminal proceedings of unified conceptual approaches to the volume, form, mechanisms and the limits of implementation of the constitutional principle of competition in regulating various legal relations in the area under consideration.