In July 1889, Parisian bailiff Toussaint-Augustin Gouffe vanished, only for his decomposed remains to be found in a trunk near Lyon. The investigation swiftly pointed to Michel Eyraud and his young mistress, Gabrielle Bompard. While Eyraud fled to South America before his eventual capture, Bompard surrendered and offered a revolutionary legal defense: she claimed Eyraud had placed her under a hypnotic trance, stripping her of free will during the murder.
This defense capitalized on a fierce real-world debate between two rival French neurological schools. The Nancy School, led by Hippolyte Bernheim, argued that hypnosis could make an innocent person commit violent crimes against their will. Conversely, Jean-Martin Charcot's Salpetriere School maintained that hypnosis only worked on hysterical individuals who retained moral choice.
During the sensational 1890 trial, expert medical witnesses bickered in open court over whether Bompard was a helpless somnambulist or a cold-blooded manipulator. Ultimately, the jury remained skeptical of total hypnotic compulsion. Eyraud was sentenced to death and guillotined, while Bompard received twenty years of hard labor.
The trial remains a landmark moment where emerging psychiatric science collided dramatically with legal accountability.