Patrice Alègre was born on June 20, 1968, in Toulouse, France. His father was a police officer, and his mother was a teenage hairdresser. His early family life was troubled. His father was known to be violent, and his mother often had relationships with other men, which sometimes happened in front of him.

Alègre grew up in a suburb called Saint-Geniès-Bellevue. He struggled in school, being expelled from three different secondary schools. Eventually, he decided to focus on general mechanics as his field of study. After some time, he moved in with his grandmother in the Izards district of Toulouse. He lived with her for 14 years.

While living with his grandmother, Alègre dropped out of school after the fourth grade. He started to engage in delinquent behavior, which included theft and drug trafficking. By the age of 13, he became homeless. During this challenging time, Alègre later told his psychiatrists that he had experienced sexual abuse.

At the age of 16, he committed his first sexual assault. In early 1988, he met a woman named Cécile Chambert. They had a daughter together the following year. 

Patrice Alègre committed a series of crimes from 1989 to 1997, primarily targeting women. His first confirmed victim was Valérie Tariote, a co-worker, who he killed on February 21, 1989. Over the years, Alègre's violence escalated. He raped and strangled several women who rejected his advances.

On January 25, 1990, he killed Laure Martinet. Then, on February 11, 1997, he attacked Martine Matias, who was beaten and rendered unconscious. Her house was set on fire afterward. On March 1997, Alègre attempted to kill Emilie Espès, but she managed to escape.

Later in June 1997, he targeted Mireille Normand, whom he raped and killed, burying her body in her garden. On September 4, 1997, he committed another murder, this time against Isabelle Chicherie. Alègre strangled her and then burned her body.

The police started investigating Alègre when they found some of Chicherie's jewelry among his possessions. They conducted surveillance on him, which led to his arrest on September 5, 1997. During the investigation, Alègre confessed to five murders and several rapes.

After his arrest, the police reopened several unsolved murder cases, suspecting Alègre may have been involved. Some former prostitutes claimed he was part of a sex trafficking ring. These claims led to additional investigations surrounding Alègre's actions and connections with local authorities.

Alègre was ultimately sentenced to life imprisonment in 2002. The case drew attention not just for the crimes he committed but also for the alleged cover-up involving police and judicial officials.