R. Austin Freeman 
The Red Thumb Mark [EPUB ebook] 

Richard Austin Freeman (11 April 1862 – 28 September 1943) was a British writer of detective stories, mostly featuring the medico-legal forensic investigator Dr. Thorndyke. He claimed to have invented the inverted detective story (a crime fiction in which the commission of the crime is described at the beginning, usually including the identity of the perpetrator, with the story then describing the detective’s attempt to solve the mystery). Freeman used some of his early experiences as a colonial surgeon in his novels.
Many of the Dr. Thorndyke stories involve genuine, but often quite arcane, points of scientific knowledge, from areas such as tropical medicine, metallurgy and toxicology (font:Wikipedia)