Rudolf Pleil was born on July 7, 1924, in a small village near the border of what was once Czechoslovakia. His father was an industrial worker and a communist. When the Nazis came to power, Pleil's father was arrested. The family then moved to Vejprty, a nearby town in the Czech Republic. When Rudolf was just nine years old, he had to help support his family by smuggling goods across the border, which led to him being arrested multiple times. Because he needed to bring in money for his unemployed parents and his sister, he did not go to school regularly. His family faced many hardships. His brother died young, and his older sister was forcibly sterilized due to epilepsy, as mandated by Nazi laws. At the age of 13, Pleil had his first sexual experience with a prostitute.

By 1939, at age 15, he left home. He started working as a butcher but quit after a few weeks. Then, he took a job as a shipboy on barges on the Elbe and Oder rivers. Pleil also engaged in small illegal businesses during this time. In the summer of 1939, he was hired as a machine boy on a merchant ship heading to South America. However, when World War II began, he joined the Kriegsmarine but was sentenced to one year in prison for theft.

On October 26, 1943, Pleil was found unfit for service due to epileptic seizures and was released. After that, he worked as a waiter but continued to have seizures. Doctors recommended that he be sterilized because of his condition, but a bomb attack destroyed the hospital just days before the procedure was scheduled. Earlier in his life, Pleil had fathered an illegitimate child, and his sister took care of the child.

Rudolf Pleil's crime spree began in the chaotic aftermath of World War II. Working as a frontier worker in the Harz region, he became involved in illegal activities that included helping people cross the border. During this time, he committed numerous rapes and murders, collaborating with two accomplices, Karl Hoffmann and Konrad Schüßler. Between 1946 and 1947, it is believed he killed at least 12 women.

Pleil's first known victim was a 32-year-old woman named Erica M. He raped, robbed, and killed her. Over the next few months, he and his accomplices lured women with false promises, only to violently attack and kill them. They used various methods, including bludgeoning with hammers and stabbing with knives.

Pleil was arrested on April 18, 1947, after the murder of Hermann Bennen, a businessman. Bennen was killed during a robbery, and his dismembered body was found in a creek. At this point, the police were already investigating Pleil for the murders of several women whose bodies had been discovered in the nearby border area. Following his arrest, evidence linked him to more than just the murder of Bennen.

While in custody, Pleil made shocking claims about his actions. He confessed to numerous other murders, boasting about his crimes and alleging that he had killed as many as 25 people. This confession drew significant media attention, which Pleil seemed to relish. His trial began on October 31, 1950, where he faced multiple charges of murder.

In November 1950, he was found guilty of several murders and was sentenced to life imprisonment. However, Pleil continued to insist on his notoriety and claimed even more victims. His prison years were marked by despondency, and on February 16, 1958, he took his own life by hanging in his cell.