Investigatory detective work is investigatory measure that is performed in public places directly (in person) by an official of the authority performing investigatory operations in order to determine, by observation and tacking, facts, things and persons related to criminal activity, to prevent or uncover criminal offences, threats to interests of importance to the state, state security and defence and to search for criminals and missing persons. In carrying out the tasks of the investigatory process, officials of the body performing investigatory operations are entitled with the approval of a prosecutor to perform investigatory detective work by becoming involved in a criminal environment (directly or under false identity), establishing contacts with persons set out in the investigative record and persons associated with them. Such activity and the identity of the officials is a secret.