He authored several books about his military career, touching sensitive political subjects of the Mitterrand era.
He was the second officer of the GIGN Special Forces unit for 10 years, before being involved in the creation of the Counterterrorist Cell of the Élysée during François Mitterrand's first mandate from 1981 to 1988.
Barril was involved in several famous affairs, such as the so-called "Irish of Vincennes" and the Elysée wiretap scandal.
Barril declared to journalists of Le Monde and France 2 that he was in possession of the black boxes of the plane and promoted the thesis that the FPR (Rwandan Patriotic Front), led by the Tutsi Paul Kagame, was involved in the attack.
[6] At the same time, on 20 May 1994, Barril was hired by the Hutu temporary government to recover a US$1.65 million payment made for canceled weapon imports.