Because I wanted to read or reread the first detective stories, this kind created in the second half of the nineteenth century, I discovered Emile Gaboriau, creator of the particular agent of the Sûreté Lecoq whose adventures appeared in serial form. Note that it is explicitly mentioned by Conan Doyle in the early writings involving his hero to him, the famous detective Sherlock Holmes.
This story of a little less than a hundred pages, puts us in the presence of police Mechinet accompanied by a medical student Godeuil (we can do here as a parallel to Dr. Watson Conan Doyle). I leave you the pleasure of following this well-crafted story, told with a fluid and pleasant style as already emphasized in its previous comment Gwen mine.