Les expertises dans l'affaire Lafarge ou la fabrique du doute

This paper focuses on the role of expertise in the trial of Marie Lafarge, accused of poisoning and killing her husband Charles Pouch-Lafarge on 14 January 1840. Historians have argued that testimonial evidence remained dominant in French criminal law throughout the nineteenth century, thus minimizing the part taken by expert testimony. Lafarge's case provides an opportunity to revisit this claim. Instead of generating certainty, expert opinion in this case created doubt and opened up new questions. Despite the contradictions of expert opinion, Lafarge was convicted. Doubt has been little discussed in the scholarship on expertise, but it is more frequently invoked in the context of agnotology - the making of culturally induced ignorance. The controversy surrounding the Lafarge case serves to illuminate the mechanisms by which doubt could arise, how people reacted to it, and how doubt was configured within an emerging medicolegal expertise.