Between 1992 and 1997, he raped 37 (some sources say 39) underage girls and killed 12 people in the city of Tolyatti, in the Samara Oblast.
Subsequently, when the corpse was discovered, experts could not immediately determine the sex of the victim due to the heavy mutilation.
Not long thereafter Rylkov was detained by police for public intoxication and lacking his identification papers, but was released after three days.
This time there were witnesses who claimed to have seen Rylkov with the girl on Topolina Street in Tolyatti, and a facial composite was soon created.
A few days later a police patrol, under the guise of selling counterfeit money, arrested Rylkov, who pretended to be a friend of his named Yashchenko.
The investigation team working on the case of the "Novokuznetsk Monster" was initially unsuccessful in capturing Rylkov.
In early 2012, Rylkov admitted that on the evening of 27 May 1994 in the attic of a house on the Ordzhonikidze Boulevard, he raped a 12-year-old child.
In 2013, Rylkov confessed to murdering a 45-year-old woman in 1993, whose corpse was found with multiple knife injuries to the chest in the forest near the "Prilesye" sanatorium.