The Leavenworth Case By Anna Katherine Green The Leavenworth Case (1878), subtitled A Lawyer's Story, is an American detective novel and the first novel by Anna Katharine Green. Set in New York City, it concerns the murder of a retired merchant, Horatio Leavenworth, in his New York mansion. The popular novel introduced the detective Ebenezer Gryce, and was influential in the development of the detective novel. In her autobiography, Agatha Christie cited it as an influence on her own fiction. Green adapted the novel into a play first performed in 1891. A later revival of the play starred Green's husband Charles Rohlfs. The story was filmed in movies of the same name in 1923 and 1936.