Lastennet was born on January 19, 1971 at Brest. He trained in catering, worked seasonally as a waiter, and by his early twenties was living in the southern suburbs of Paris with a long-standing cannabis habit and a spell of voluntary psychiatric treatment behind him.
Between August 24, 1993 and January 1994 he killed five women in their own flats: Marcelle Cavilier, eighty-seven; Antoinette Bonin, seventy-six; Raymonde Dolisy, seventy-two; Augustine Royer, ninety-one; and Violette de Ferluc, ninety-two. They were at Chevilly-Larue, Thiais, Bourg-la-Reine and Boulogne-Billancourt, in the Val-de-Marne and the Hauts-de-Seine. He talked his way in, strangled them, and took cash and small valuables.
Every one of them lived alone, and every address was on the same bus route. That was the link, and it is what turned five separate deaths of very old women, the kind of death that is easily recorded as unremarkable, into one investigation.
He was arrested at his flat on January 12, 1994. He gave no resistance, confessed at once, and the property taken from the flats was found at his home.
He was tried at the cour d'assises of the Val-de-Marne in October 1997 and sentenced to life imprisonment with an eighteen-year security period, during which no release could be considered.
He died on December 19, 2023 at the Poitiers-Vivonne prison, aged fifty-two. He had been in custody continuously since January 1994, almost thirty years, and was never released. The entry that stood here said he would have been eligible for release from the mid-2010s and that nothing recorded his position; the answer is that he stayed in prison until he died there.