Special evidentiary actions are procedural actions taken to detect and prove the commission of criminal offenses and their perpetrators. These are secret and covert actions that are taken for the purpose of gathering information, without warning the persons against whom the actions are being taken. As evidence of fundamental human rights and freedoms is specifically proved by evidentiary actions, they are undertaken only if the investigations can be carried out in another way or would be possible only with disproportionate difficulties. In addition, the legislator is obliged to strictly monitor the implementation and application of special evidentiary actions in the form of judicial control, with the aim of preventing illegal actions, ie protection of human rights and freedoms. Entities participating in the procedure of enacting and conducting special evidentiary actions in Croatian legislation are: the State Attorney, the police and the investigator. As a rule, the order to conduct special evidentiary actions is issued by court investigations at the request of the State Attorney. In exceptional cases, the order may be issued by the State Attorney within 24 hours. The police execute the order to take special evidentiary actions. Special evidentiary actions of secret surveillance and technical recording of persons and objects are a special type of conservation, but they cannot be carried out as a stationary or mobile supply with technical recording of a person and objects that are monitored. The aim of the measures is to collect data on the overall activities of the persons over whom the measure is implemented. Enforcement is the responsibility of the police.