When Edgar Allan Poe began writing mystery stories during the 1840’s, he not only inadvertently created the template for a new literary genre—detective fiction—but he also introduced the first armchair detective, C. Auguste Dupin. Dupin solves crimes that the police cannot. In “The Mystery of Marie Rogêt” (1842), set in Paris but based upon an actual murder near New York City, Dupin obtains his information from newspaper accounts. The story is made up of summaries of those articles by Dupin’s housemate, who serves as has chronicler, and Dupin’s commentary and conclusions. This first armchair detective and his descendants gather information primarily at second hand, rather than through personal observation. They succeed by using their intellects, intuition, and logical reasoning powers, which Poe called ratiocination, to deduce solutions. Sedentary chaps, armchair detectives rarely visit crime scenes or interview witnesses and suspects themselves. Unlike their descendants, however, Dupin and his chronicler are undeveloped and shadowy figures, although Dupin’s unnamed, loyal amanuensis clearly has limited intellect and imagination.
In a footnote to “The Mystery of Marie Rogêt,” Poe writes that the story was composed at a distance from the scene of the atrocity, and with no other means of investigation than the newspapers afforded. Thus much escaped the writer of which he could have availed himself had he been upon the spot and visited the localities.
Early in the story, Dupin’s housemate and chronicler says that he “procured, at the Prefecture, a full report of all the evidence elicited,” along with copies of every newspaper containing “any decisive information in regard to this sad affair.” After the two men review the news reports, Dupin asks his unnamed friend to check the validity of affidavits while he examines the newspapers “more generally than you have done.” His associate, however, fails to see the object of Dupin’s efforts.