Pierre Chanal was born on November 18, 1946, in Saint-Étienne, France. He came from a background typical for many French families of that time. As a child, he grew up in a country recovering from World War II. Pierre's early life details are not widely known, but he later became known for his military service.

Chanal joined the military and had a notable career. He served as a chief warrant officer and instructor at Camp de Mourmelon in the 4th Dragoon Regiment in the Marne region. He worked there from 1977 to 1986 and was respected for his service. Chanal's superiors found his behavior to be exemplary. He regularly jogged long distances, showing dedication to fitness. He was also trained in hand-to-hand combat and enjoyed skydiving as a hobby.

In addition to his training and fitness, Chanal served as a United Nations peacekeeper in Lebanon. His deployment lasted from January 18, 1985, to May 15, 1985. During this time, he earned a United Nations medal for his efforts.

On 9 August 1988, police from Saône-et-Loire discovered a Volkswagen Type 2 microbus parked on a dead-end road near a construction site for a TGV line in Bussières. When they approached the vehicle, they found Pierre Chanal inside. He claimed to be a non-commissioned officer on leave for tourism. The police asked for his identification and soon realized his connection to a series of disappearances in Mourmelon. While searching the vehicle, they spotted a wrapped head of a man in the back. This man was Balázs Falvay, a 20-year-old Hungarian hitchhiker. Falvay accused Chanal of kidnapping and raping him.

During the investigation, police found sex toys and a camera containing images that matched Falvay's statements. On 23 October 1990, Chanal was convicted of kidnapping and rape, receiving a ten-year sentence. He served time in a prison in Dijon and requested solitary confinement. He remained silent throughout the trial. Chanal was released on 16 June 1995. After his release, police continued to suspect him in relation to the Mourmelon disappearances.

From 1980 to 1987, eight young men vanished in the Mourmelon region. Five soldiers disappeared while on leave between 1980 and 1982. There were also cases of a civilian in 1985 and a soldier in 1987 who went missing. Two bodies were recovered near the camp during this timeframe. One was of a soldier named Olivier Donner, found in 1982. The other was of an Irish tourist named Trevor O'Keefe, discovered in 1987, partially buried.

Chanal was eventually found dead on 15 October 2003 while on trial. He had died by cutting his femoral artery with a razor.