In-joke: The character played by Barbara Stanwyck is named Helen Ferguson; this is the real name of one of best-known Hollywood publicists of the era, who also represented Stanwyck.
First film adaptation of American crime novel "I Married a Dead Man" (1948) by Cornell Woolrich under the pseudonym William Irish.
The big car owned by the Harkness family is a 1946 Chrysler New Yorker Sedan.