ENThe paper consists of two parts: one - analysis of obtaining permission to conduct pre-trial investigative action from economic aspects and another on the lessons learned in the Republic of Lithuania during the reforms in the civilian security sector. An essential component of an effective pre-trial investigation is not just investigative actions prescribed by criminal procedure laws, their procedures for conduction during one of the criminal process stages – a pre-trial investigation, qualification of investigators, prosecutors, their skills, secondary law that regulates conduction of investigative actions in details. Also, how does the investigative action work at the preliminary stage of conducting the investigative actions? Is it effective and efficient? For example, in obtaining permission for such actions as a search, covert surveillance, or wiretapping. The author analyses investigative actions from an economic point of view in the first part of this paper. The paper aims to introduce obstacles, misunderstandings, and committed mistakes before launching and during the implementation of the reforms in the Lithuanian criminal justice system after the collapse of the Soviet Union, namely, in the civilian security sector. The author of this paper presents his experience through bullet points named “lessons learned” of being a participant in the above-mentioned reforms. The outcomes of this paper are going to be important in light of the reform in the civilian security sector launched and still going on in Ukraine after the Revolution of Dignity of 2014. It helps to avoid mistakes that were made during reforms in the Republic of Lithuania. Keywords: an investigative action, police investigator, a prosecutor, a court, a criminal proceeding, resources, reform. [From the publication]