Which author created Sherlock Holmes?

Arthur Conan Doyle, who resented him. Doyle wanted to be taken seriously as a historical novelist and regarded the detective as a distraction, writing to his mother that he was thinking of killing him off because Holmes takes my mind from better things. He pushed him over the Reichenbach Falls in 1893 and was forced by public outrage and a very large offer to bring him back nine years later.

The method was borrowed from a real person. Joseph Bell, a surgeon who taught Doyle at Edinburgh, would deduce a patient's occupation and recent travels from their hands, gait and accent before they had finished sitting down, and used it to teach students to observe rather than assume. Doyle wrote to him acknowledging it directly.

The stories then fed back into real forensics. Holmes is using fingerprints, footprint casts, cigarette ash analysis and blood tests before police forces routinely did, and early forensic scientists including Edmond Locard cited the stories as an influence on how they thought the work should be done. Doyle himself also twice took up real criminal cases and helped clear two wrongly convicted men, which contributed to the creation of the Court of Criminal Appeal in England.