Connington, J.J. The Castleford Conundrum (Boston: Little, Brown, 1932) 340 p.
Investigating a shooting at a country estate, a police detective looks for clues in the nearby town. The librarian is Mr. Tenbury.
The Chief Librarian of the Strickland Regis public library was an alert little man, full of enthusiasm for his work. His tawny hair, bright eyes, and staccato movements, called up in Wendover's mind the comic simile of a squirrel in horn-rimmed spectacles. (p. 291).
Tenbury has no scruples about handing the police the circulation records of all the estate's residents.