Death in Duplicate — George Douglas

Bill Hallam, newly appointed as Detective Chief Superintendent of the North Central Regional Crime Squad, is faced with an outbreak of thefts from stately homes in the district. The loot from one of these is promptly returned to the police, but this puzzle takes second place when Alfred Beal, an employee of Oversby House, is found murdered near the most valuable of Lord Oversby's treasures. Then, Beal's actress daughter also meets her death, in a hotel bedroom...