The Rule of law in the practice of applying preventive measures: between the effectiveness of criminal prosecution and the protection of individual liberty

The article examines the implementation of the rule of law in the practice of applying preventive measures as the most intensive form of procedural interference by the state with the right to liberty and personal security. It is substantiated that, in this sphere, the rule of law should be understood not as a declarative principle but as a practical standard for controlling the discretion of the investigating judge and the court, manifested through the requirements of legal certainty, non-arbitrariness, proportionality, subsidiarity (alternativeness), and the verifiability of judicial decisions. It is demonstrated that the “quality of the law” in detention-related decisions encompasses not only the formal existence of a procedural rule but also its foreseeability, coherence, and the capacity of the legal procedure to prevent arbitrariness through substantive judicial control, proper reasoning, and the possibility of effective review. It is proven that reasonable suspicion serves as a primary filter of the lawfulness of restricting liberty by establishing a minimum threshold of factual sufficiency and precluding the application of custodial measures based on assumptions. Risks are revealed as a prognostic ground that must be proven on the basis of specific factual indicators, with mandatory individualization and a prohibition on template reasoning. It is established that proportionality and genuine alternativeness constitute the “core” of the rule of law when selecting a preventive measure and preclude the automatic application of pre-trial detention, requiring an analysis of less intrusive means and proof of their insufficiency in the конкретe case. Emphasis is placed on the dynamic nature of judicial control over detention: grounds that are sufficient at the initial stage may lose their persuasiveness over time, which necessitates updating the factual justification and reassessing risks at each extension of detention. Practical recommendations are proposed regarding the structure of judicial reasoning, a “grounds-renewal test,” standards for assessing alternatives and the temporal parameters of liberty restrictions, as well as safeguards against abuses of procedural rights and powers. Particular attention is paid to the fact that, under martial law, heightened risks cannot serve as a basis for lowering standards of proof and judicial control; on the contrary, they require strengthening guarantees of non-arbitrariness and minimizing interference with personal liberty.