Hercule Poirot and Frank Howel Evans' Monsieur Poiret, a retired Belgian police officer living in London. A more obvious influence on the early Poirot stories is that of Arthur Conan Doyle. In "An Autobiography", Christie states, "I was still writing in the Sherlock Holmes tradition – eccentric detective, stooge assistant, with a Lestrade-type Scotland Yard detective, Inspector Japp". For his part, Conan Doyle acknowledged basing his detective stories on the model of Edgar Allan Poe's C. Auguste Dupin and his anonymous narrator, and basing his character Sherlock Holmes on Joseph Bell, who in his use of "ratiocination" prefigured Poirot's reliance on his
Police procedural gathering evidence, search warrants, interrogation and adherence to legal restrictions and procedure. The roots of the police procedural have been traced to at least the mid-1880s. Wilkie Collins's novel "The Moonstone" (1868), a tale of a Scotland Yard detective investigating the theft of a valuable diamond, has been described as perhaps the earliest clear example of the genre. As detective fiction rose to worldwide popularity in the late 1800s and early 1900s, many of the pioneering and most popular characters, at least in the English-speaking world, were private investigators or amateurs. See C. Auguste Dupin, Sherlock Holmes, Sam Spade, Miss