''Helen Passes By'' by E. R. Punshon (d. 1956), public domain. This gripping tale plunges Deputy Chief Constable Bobby Owen into a politically charged murder investigation involving an aristocratic family, a murdered businessman, and a beautiful, elusive woman who seems to captivate all who cross her path.
When a local businessman named Itter Bain is found shot in the woods, the investigation becomes highly controversial due to the alleged shielding of a local aristocratic suspect. Bobby Owen is called in to navigate the politically sensitive case without triggering a national scandal. With almost no physical evidence or fingerprints to go on, Owen must rely on psychology and unravel a web of confusing, contradictory behaviors from various witnesses.
The title character, the beautiful Helen, is believed to have been near the crime scene and becomes a person of interest. Along with Helen, suspects include a rival for her affections, a local aristocrat, and a curiously well-informed journalist.