Émile Gaboriau was Féval’s secretary, sometimes his ghost writer, and an editor of his magazine Jean Diable. Before becoming successful as a feuilletoniste, Gaboriau worked on the fringes of the literary world. He edited a small journal, wrote advertising jingles and short satirical articles, as well as researched and published semi-historical stories of royal mistresses (Les Cotillions célèbres) (1861). While he owed much to Féval, his plots are plebeian compared to Féval’s. He wrote no stories about vampires, international conspiracies, or swashbuckling cape and sword heroes. His sinners and the innocent are all too real. Lust, murder, revenge, theft, and jealousy filled Gaboriau’s pages. The television series Law and Order could not show more.

L’affaire Lerouge, Gaboriau’s first successful novel, introduced a secondary character, a young man advised by his first regular employer to make a career choice: to use his superior analytical ability to become either a member of the judicial system or a master criminal. At twenty-five he chose the French Sûreté. This character, Monsieur Lecoq, who never has a first name, appears in four more novels. He serves his apprenticeship in Affaire Lerouge with an independently wealthy amateur detective, Père Tabaret, later his mentor. The popularity of Lecoq’s character led Gaboriau to publish as feuilles, over a period of three years, four more Lecoq novels: Le Crime d’Orcival (1867), Le Dossier 113 (1867), Les Esclaves de Paris (1868), and the final novel in the series, Monsieur Lecoq (1869).

Gaboriau called his novels in the Monsieur Lecoq series romans judiciaries, novels about the judicial system. Prior to the late nineteenth century, the French police had a well-deserved bad reputation. They frequently used criminals as informants, inserting them into the dens of criminal Paris, located then in the barrio around the rue St. Jacques. Political and student unrest had caused barricades to be thrown up in that area and remained there until Baron Haussmann (1809-1891), under the reign of Napoleon III, renovated the Parisian water and sewage systems, demolished buildings and cut through new streets to allow fire and police brigades access to the entire city. Gaboriau’s Monsieur Lecoq begins in the barrio of that pre-Baron Haussmann era.

Like some of his predecessors (Balzac’s Vautrin in Père Goriot; Victor Hugo’s Jean Valjean in Les Misérables; Alexandre Dumas’ Jackal in Les Mohicans de Paris), Gaboriau based some of Monsieur Lecoq’s talents on François Vidocq, a master criminal. After serving in the army, Vidocq was convicted of forgery and sentenced to prison. While in prison, he forged documents for a fellow prisoner and had his sentence extended. He escaped several times, using disguises and imaginative ploys to elude the police. He escaped twice from the galleys, once dressed as a sailor, once as a member of a funeral cortege. After his release, he was recruited by the police to spy on his former colleagues and report their illegal activities. He was so successful that he brought together eight friends, also former criminals, and began the Sûreté Nationale in 1811. It was also a successful venture that helped to reduce crimes in Paris enormously. Gaboriau borrowed three of Vidocq’s more useful — and most often used — techniques from Monsieur Lecoq, who is also a consummate actor, master forger, and talented make-up artist.