Sergei Vasilyevich Ryakhovsky was born on December 29, 1962, in the Saltykovka area of Balashikha, Moscow Oblast. This city is located just east of Moscow, about one kilometer away. Ryakhovsky was notably tall, standing at 6 feet 6 inches, and he weighed around 280 pounds.

Growing up, Ryakhovsky's early life is not well-documented, but by the early 1980s, he began to experience troubling feelings. In 1982, he mentioned that he had an "irresistible desire for intimacy with a woman." This led him to commit several serious acts. He attempted to assault elderly women in the Golyanovo area of east Moscow. As a result of these actions, he was convicted of hooliganism and sentenced to four years in prison.

In June 1988, Sergei Vasilyevich Ryakhovsky committed his first murder in Bitsa, a village near Moscow. This was followed by the killings of three homosexual men in Izmailovski Park. Ryakhovsky stated that these murders were part of a mission to "cleanse" society of homosexuals and prostitutes. Between 1988 and 1993, he mostly targeted elderly women but also murdered five men and two teenagers. Ryakhovsky typically killed his victims by stabbing them or strangling them with his hands or a rope. After his victims were dead, he would mutilate their bodies, especially in the genital area. Some of his victims were sexually violated postmortem.

In January 1993, Ryakhovsky murdered a 73-year-old man, decapitating him with a hunting knife. He returned the next day to cut off the man's leg. Later, a 65-year-old woman was killed using a weak pyrotechnic device which ruptured her abdomen. His final known victim was a 16-year-old boy whom he hanged, eviscerated, and decapitated with a knife.

Ryakhovsky was arrested on April 13, 1993, after police discovered a shack he used for his crimes. He did not resist arrest. The Russian media gave him the nickname "The Balashikha Ripper" due to his appearance and the nature of his crimes. During the investigation, he cooperated with police, sharing details about the crime scenes and methods. Most of his murders were impulsive, except for the planned killings of the three men in the park.

Psychiatrists assessed him as sane and responsible for his actions. However, after learning about his diagnosis, his cooperation declined, and he began to obstruct the investigation. In July 1995, he was sentenced to death but later had his sentence commuted to life imprisonment in a maximum-security prison due to a moratorium on the death penalty in Russia.

Ryakhovsky died on November 12, 2007, from untreated tuberculosis while serving his life sentence.