Though not cited in the opening credits, the film is based on a 1939 novel of the same name by Joseph Shearing (1885-1952), a pseudonym for Marjorie Bowen. A prolific writer with a taste for the Gothic, Bowen also wrote "Moss Rose" which came to the screen in 1947 (Moss Rose (1947) with Victor Mature and Peggy Cummins.
Based on a real 1848 murder case.
M.E. Clifton James, who appears as the prison governor, is most famous for his impersonation of Gen. Bernard L. Montgomery in the run-up to D-Day.