In 1854, Ivan Putilin began working in the police of Saint Petersburg, taking the position of district supervisor in the city’s most dangerous area—the Sennaya Square and its surroundings (Spasskaya part). For his achievements in investigative work, he was awarded four orders. In December 1866, Putilin became the first head of the detective police of Saint Petersburg. Before his death in 1893, he completed work on his memoirs «Forty Years Among Thieves and Killers.» Arkady Koshko began his service in Riga’s police in 1895 as an assistant to the precinct chief in the first (then second) section of the Mitava part. In October 1906, he became deputy head of the detective police of Saint Petersburg, and from February 1908 he led the Moscow detective police. In his last years, he wrote stories about his service. The book compiles the memoirs of Putilin and Koshko about criminals in Saint Petersburg whose actions shocked and frightened the city’s residents.