Sergey Alexandrovich Kashintsev was born on 9 August 1940 in the village of Podyuga, located in Arkhangelsk Oblast, RSFSR. From birth, he faced challenges due to a physical defect that caused his right leg to be shorter than his left. This condition made him rely on a cane to walk. As a result, he was often teased and bullied by other children.

As he grew up, Kashintsev showed signs of aggressive behavior. His acting out included small crimes. His aggression was so intense that even his mother became afraid of him. He did not want to attend school or hold a job. Rather, he often ran away from home. In 1955, he committed a serious offense by luring a young girl into a bathhouse and convincing her to undress.

Kashintsev's first confirmed murder occurred on July 25, 1985, in Chelyabinsk. He met a 34-year-old woman named Larkova and invited her for a drink. After drinking together, they went to the regional Glinka Opera and Ballet Theater, which was under construction. There, he attacked her, tearing off her clothes and beating her with his fists and a stick. He ultimately strangled her to death with his bare hands.

On January 8, 1986, Kashintsev met a 57-year-old woman, Fyodorova, at a railway station in Kirov. He took her to an apartment where others were staying. When everyone else fell asleep, he grabbed Fyodorova by the neck and dragged her to the bathtub. There, he bashed her head against the side of the tub. After she fell, he strangled her and then used a rasp to strike her repeatedly until she was dead.

Kashintsev followed a similar pattern with other victims. He often targeted women who were vulnerable due to drinking or difficult circumstances. Many of his victims remained unaccounted for because of their lifestyles, and their deaths were sometimes attributed to accidents or natural causes.

On April 28, 1987, railroad workers in Ryazan Oblast found a woman lying dead on the ground. They saw Kashintsev sleeping nearby and alerted authorities. During his interrogation, Kashintsev claimed to have committed 59 murders, but many of his confessions were not verified. He was ultimately charged with seven murders and three attempted murders.

Kashintsev underwent a psychiatric evaluation that revealed some brain damage but indicated he was still able to understand his actions. He was put on trial and found legally sane. On March 13, 1990, he was convicted and sentenced to death. He was executed on January 17, 1992, in Russia.