TY JOUR TI The extreme necessity and its importance in operational and investigative activities KW criminal law KW criminal legislation KW crime KW circumstances precluding the criminality of the act KW extreme necessity KW operational-search activity KW legislation on operational-search activity JO Vestnik of the St. Petersburg University of the Ministry of Internal Affairs of Russia AU Nikulenko, A.V. PY 2019 IS 2019 PB SAINT-PETERSBURG UNIVERSITY OF THE MINISTRY OF INTERNAL AFFAIRS OF THE RUSSIAN FEDERATION