Monique Olivier was born at Malesherbes on May 4, 1948, into a violent household, and married a man who beat her. In 1987, unhappy and isolated, she answered a prison correspondence advertisement and began writing to Michel Fourniret, who was serving a sentence for sexual assaults on minors.
The letters became an arrangement. She would help him find and approach virgins; he would kill her former husband. They married in 1989 on his release and moved to the Ardennes.
Her role was practical and indispensable. A man alone in a van does not get a teenage girl to stop. A woman does, especially a woman with a child in the car, and Olivier drove, asked directions, offered lifts, and in some cases held the victims down. She was convicted at Charleville-Mezieres in May 2008 as an accomplice to the murders of seven young women and girls, and sentenced to life with a minimum of twenty-eight years.
She kept talking after that, in pieces, over years, and her statements are the reason several cases were ever resolved. In 2018 she gave evidence that led Fourniret to admit the killing of Estelle Mouzin, a nine-year-old who disappeared in 2003, and to the recovery of information about others.
In November and December 2023 she was tried again in Nanterre, five years after Fourniret's admissions and two after his death, for complicity in the murders of Estelle Mouzin, Marie-Angele Domece and Joanna Parrish, a British student killed at Auxerre in 1990. She was convicted on all three counts and given a further life sentence with a twenty-year minimum. The Parrish family had waited thirty-three years.
How much she was a coerced woman and how much a willing participant was argued at both trials. The courts found her a participant.