AllMovie

Nurse Sarah Keate, the middle-aged crime-solver created by mystery novelist Mignon Eberhardt, was reshaped as a much younger and prettier woman in Murder by an Aristocrat. Marguerite Churchill is the white-clad heroine, here rechristened Sarah Keating, while Lyle Talbot is her doctor boyfriend Allen Carick. The murder of the title takes place in a Old Dark House where Sarah is presently employed. The victim is nasty Bayard Thatcher (William B. Davidson), who supplements his income by blackmailing the various members of his family. Naturally, all of the other Thatchers are suspected of the crime, but the list narrows as they themselves are bumped off one by one. With nary a cop in sight, Sarah takes it upon herself to solve the mystery before she ends up on a morgue slab.