The subject of the study is the professional work of the preliminary investigation bodies aimed at finding and forming an evidence base in the investigation of crimes related to drug trafficking. The object of the study is the social relations developing in the field of countering illicit drug trafficking. The statistical method of the study showed that the number of these crimes does not cease to grow. According to the data of the Ministry of Internal Affairs of the Russian Federation, in January 2023, an increase in registered crime was recorded by 1.1%, due to a certain extent to an increase in the registration of facts of the sale of narcotic drugs by 42.2%. Cybercrime rates increased by 14.2%. Drug sales using information and telecommunication technologies were increased by 85.1%. The authors focused on the establishment of circumstances that are subject to verification and evaluation in terms of the admissibility of evidence for a successful investigation of such crimes, studied methods of contactless drug sales, as well as preventive measures aimed at combating drug crime. The conducted research allowed us to come to the conclusion that the fight against illicit trafficking in narcotic drugs and psychotropic substances, regardless of the method of committing a crime (direct or contactless), should be carried out taking into account the entire complex of operational investigative, criminal procedural measures aimed at identifying and exposing drug traffickers by distributing "bookmarks". We will not allow a formal approach to finding and securing evidence for such crimes in order to ensure the effectiveness of criminal prosecution.