Limits of Applying Secret Surveillance Measures: Legality Criteria and Possibilities for Evidence Use

Abstract

The importance of procedural coercive measures in law enforcement is constantly growing; therefore, it is important to ensure the legality of their application and to remain within the limits established by law. The subject of this study is covert surveillance as one of the procedural coercive measures. The aim of the study is to identify the limits of the application of covert surveillance, as well as the criteria of legality and proportionality. It has been established that covert surveillance is applied only in exceptional cases when it is necessary to obtain information relevant to a pre-trial investigation. The study also highlights the main differences between covert surveillance and commercial surveillance, particularly regarding their purposes, legal basis, and scope. The findings contribute to a more consistent legal assessment of covert surveillance and the improvement of its application in criminal proceedings. Furthermore, the practical application of this measure remains relevant, as it requires a constant balance between effective law enforcement and the protection of individual rights.