The Soviet criminal investigation department is rightfully considered one of the most effective law enforcement services in the history of the Fatherland. Outstanding detectives, top-class professionals, people selflessly devoted to their work served in the criminal investigation department of the USSR. Thanks to their skill, hundreds of high-profile crimes were solved and thousands of criminal groups were neutralized. This is discussed in a new book by historian and publicist Sergei Kholodov. Using a large amount of factual material, the author traces the history of criminal investigation from its formation in 1918 to the period of socio-economic reforms of the last decade of the 20th century. Many criminal cases described in detail in the book were classified as “secret” until recently.