The emergence of forensic medicine as a distinct specialty in the nineteenth century sparked debates about the extent which it could reveal truth, furnish legal proof, and serve justice. This question was particularly salient in the context of the institutional and juridical changes that the French Revolution had created, which transformed the field of legal medicine. This introduction provides an overview of the legal landscape in which medicolegal experts operated, the professionalization of medicine, and the rising influence of medical experts in French criminal courts and beyond.