Compliance with the rule of law in conducting covert investigative (detective) actions

It is indicated that secret investigative actions, by their legal nature, are a form of covert state interference in the sphere of private life and communications, that is, in those values that have a constitutional and conventional level of protection and can be limited only if there is an appropriate legal basis, in cases specified by law and in the manner prescribed by law. The article substantiates a procedural and doctrinal model for ensuring compliance with the rule of law during the initiation, authorisation, conduct, and use of the results of covert investigative (detective) actions in criminal proceedings. The starting premise is that covert investigative (detective) actions, as the most intrusive instruments of secret interference with privacy and communications, cannot be legitimised solely by the formal existence of a procedural norm or a judicial authorisation; rather, they require assessment through the criteria of the “quality of law,” legal certainty, proportionality, and effective judicial oversight as a safeguard against arbitrary discretion. A three-tier structure of rule-of-law regulation for covert investigative (detective) actions is proposed: (1) the principle of the rule of law as a basic guideline for law enforcement; (2) the general provisions on covert investigative (detective) actions as a universal procedural framework for permissible interference; and (3) special safeguards for particular types of covert actions and ex post protection mechanisms. It is argued that the compatibility of covert investigative (detective) actions with the rule of law should be verified through a three-part test of suitability, necessity, and reasonableness (proportionality), which ensures a balance between the legitimate aim of criminal prosecution and the inviolability of the private sphere. The article separately analyses the problematic issue of notifying a person of a temporary restriction of rights (Article 253 of the Criminal Procedure Code of Ukraine) as a deficit of rule-of-law safeguards, as well as the non-disclosure of materials from covert actions to the defence in the context of ECtHR standards and the need for procedural compensatory mechanisms to preserve adversarial proceedings and overall fairness. The conclusion is that the real effectiveness of the rule of law in the sphere of covert investigative (detective) actions can be ensured only by increasing the legal certainty of procedures, strengthening the notification mechanism, and balancing the secrecy regime with procedural safeguards of protection.