I saw this black and white movie within the last five to seven years on TCM I think. Basically, the plot is a man and his girlfriend devise a plan for the man to tell an old woman that they will marry so he can get all of the old woman’s money, but she becomes restless and wants to leave and he hits her with a hammer in the back of the head. Then they put her body in the suitcase.
The Honeymoon Killers
http://www.imdb.com/title/tt0064437/?ref_=fn_al_tt_1