The problem of legitimacy in law enforcement activities under conditions of insufficient legislative regulation of confidential cooperation

For the effective investigation of serious or particularly serious crimes, covert investigative (search) actions are conducted, involving individuals who confidentially cooperate with law enforcement agencies. This study aimed to examine the legal parameters governing the admissibility of the results of covert investigative (search) actions as a particularly sensitive form of evidence collection, with emphasis on balancing operational expediency and procedural legality within criminal proceedings. The methodological basis of the study included a systematic analysis of Ukrainian legislative acts, as well as comparative legal methods, which made it possible to assess the effectiveness of the practical application of legislative provisions. In the context of insufficient legislative regulation of confidential cooperation with law enforcement bodies, it was necessary to analyse potential errors that may lead to the recognition of evidence as inadmissible. Attention was drawn to the possibility of conducting covert investigative (search) actions solely during the investigation of crimes of a certain degree of gravity, and subject to the proper procedure for obtaining the necessary authorisation. The article also highlighted the need for proper formalisation of the involvement of individuals confidentially cooperating with law enforcement authorities in covert investigative (search) actions, and outlines the information that must be specified in the ruling authorising such a decision. Issues concerning the declassification of protocols prepared on the basis of covert investigative (search) actions and the decisions authorising their conduct have been examined, with particular attention given to the absence of a mechanism for declassifying rulings of an investigating judge granting permission for such actions and the problems arising as a result. A mechanism has been proposed for verifying the legality of covert investigative (search) actions in cases where no ruling by an investigating judge exists to authorise such actions, or where such a ruling remains classified. The problematic issues explored in this article, together with the specified conditions for using the evidence obtained, provide a useful tool for the practical work of detectives, investigators, and operational units of law enforcement agencies