Marie Besnard (15 August 1896 – 14 February 1980), also known as 'The Good Lady of Loudun', was an accused serial poisoner in the mid-20th century.
After three trials lasting over ten years (the first held in Poitiers), Besnard was finally freed in 1954, then acquitted on December 12, 1961.
Around this time, on May 14, 1940, Marie Besnard's father Pierre Davaillaud also died, officially due to cerebral haemorrhage, although his exhumed remains contained 36 mg of arsenic.
Shortly afterward, the Besnards sublet rooms to a wealthy childless couple, the Rivets, who were friends of Marie's husband.
Madame Blanche Rivet (née Lebeau) died on December 27, 1941, from aortitis, although her remains contained 30 mg of arsenic.
As Marie had by now also accumulated most of the wealth of both families, suspicions were aroused of foul play and the magistrate ordered the exhumation of Léon's body on May 11, 1949.
Béroud's autopsy report, based on an analytical method developed by Marsh and Cribier, concluded that the victims had been slowly poisoned by arsenic.
In addition, an investigation at the cemetery was able to show that arsenic may have leached into the soil and bodies from chemicals used on the flowers and from zinc ornaments and other sources.
[2] The English historian Richard Cobb presents a sympathetic portrait of Besnard in a lengthy essay in his book about French life, A Second Identity (1969).