Investigator’s covert-nature procedural activities Marina Sergeevna Kolosovich, Lyudmila Vladimirovna Popova, Anna Fedorovna Zotova, Maria Mikhailovna Bondar and Olga Sergeevna Shamshina SHS Web Conf., 108 (2021) 04011 Published online: 31 May 2021 DOI: 10.1051/shsconf/202110804011