Gentleman detective shares some features with the later gentleman detective. He was "…the first fictional detective of importance and the model for virtually every cerebral crime solver who followed." More specifically, Dorothy L. Sayers noted that "Sherlock Holmes modelled himself to a large extent upon (Poe's) Dupin, substituting cocaine for candlelight, with accompaniments of shag and fiddle-playing." Dupin is French, not English, but is probably a "gentleman". He comes from a once wealthy family but has been reduced "by a variety of untoward events" to more humble circumstances. He is entirely amateur and contents himself only with the basic necessities of life.
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