Arthur Conan Doyle Quotes about Crime

The most difficult crime to track is the one which is purposeless.
Oldiees Publishing, Arthur Conan Doyle, Guy de Maupassant, Charles Dickens, E. W. Hornung (2014). “50 Crime Short Stories - THE BEST SHORT WORKS COLLECTION”, p.441, Oldiees Publishing
E. W. Hornung, Arthur Conan Doyle, John Kendrick Bangs (2016). “COLLECTOR’S EDITION – COMPLETE RAFFLES SERIES & SHERLOCK HOLMES ADVENTURES: 60+ Novels & Stories in One Volume (Mystery & Crime Classics): Including The Amateur Cracksman, The Black Mask, A Thief in the Night, Mr. Justice Raffles, Mrs. Raffles, R. Holmes & Co., and The Adventures of Sherlock Holmes”, p.823, e-artnow
The more featureless and commonplace a crime is, the more difficult it is to bring it home.
"The Boscombe Valley Mystery" (1891)
Ex-Professor Moriarty of mathematical celebrity... is the Napoleon of crime, Watson.
Memoirs of Sherlock Holmes (1894) "The Final Problem"
1892 The Adventures of Sherlock Holmes,'The Copper Beeches'.
Arthur Conan Doyle (2005). “The New Annotated Sherlock Holmes: The Novels (Slipcased Edition)”, p.570, W. W. Norton & Company