Robert O. Saber - The Black Dark Murders

First published in the U.S. by Handi-Books in 1949. This U.K. edition was the first book published by the short-lived Jewel Books, and is undated but is circa 1953. Jewel only published 16 novels, all of them reprints from Handi-Books, Lion and Pyramid. Cover art is taken from the Handi-Books edition, the artist unknown.