Guy Georges was born Guy Rampillon on either October 10 or 15, 1962, in Vitry-le-François, France. His mother, Helène Rampillon, was French, and his father was George Cartwright, an African American U.S. military cook stationed at a NATO base. Helène had another son named Stéphane, who was raised by her parents because they did not want to take care of Guy. This was largely due to the social stigma against mixed-race children at that time in their hometown of Angers.

Guy moved around a lot during his early childhood. He spent six years switching between foster homes and living with his mother. Eventually, he became a ward of the state and was placed with the Morin family. The Morins had seven biological children and 13 foster children. Guy was seen as a "replacement child" because the Morins had previously cared for another black child who had been taken back by the authorities. In 1968, Guy's last name was changed to Georges.

Helène moved to California with Stéphane, wanting to marry another American serviceman. This left Guy in the care of the Morin family. As a child, he started stealing food from the family store and spent time hunting with a knife in the nearby forest. He adopted the nickname "Jo," inspired by a character named "Injun Joe" from The Adventures of Tom Sawyer.

As he entered his teenage years, Georges displayed troubling behavior. At the age of 14, he tried to strangle his younger foster sister, Roselyne, who had a mental handicap. When he was 16, he attempted to strangle his older foster sister, Christiane, with an iron bar. Following these incidents, Georges was sent to a state orphanage.

From 1991 to 1997, Guy Georges committed a series of violent crimes in Paris. He assaulted, tortured, raped, and killed seven women. The victims were primarily young women aged between 19 and 32.

His first murder was on January 24, 1991, when he killed Pascale Escarfail, who was just 19 years old. After this, he continued his attacks, with notable victims including Catherine Rocher, Elsa Benady, Agnes Nijkamp, and Hélène Frinking. His last two victims were Magali Sirotti and Estelle Magd, murdered in 1997. Each crime involved sexual violence, and the murders took place in the neighborhood surrounding the Bastille.

The investigation into these crimes faced many challenges. There was no centralized DNA database in France at the time. Investigators struggled to link the crimes until DNA samples from several victims matched. In March 1998, a judge ordered a manual search to find DNA matches from private clinics. This led to Georges being identified as the killer.

Georges was arrested on March 26, 1998, by police who were conducting an unrelated operation. He confessed to the murders after his arrest but later denied it during his trial. Ultimately, he admitted to killing seven women. The trial concluded in April 2001, and he was sentenced to life imprisonment. This meant he would serve at least 22 years before being eligible for parole.