Gerald Verner

A group of people in an old dark house are terrorized by a mysterious hooded figure dressed in black who proceeds to kill them off one by one. (imdb)

Slim Callaghan, a fictional British private detective in the American "hard boiled" mode, was the central character in several popular Peter Cheyney novels, in a stage play by Gerald Verner, and in the 1948 movie programmer Uneasy Terms, which top-billed Michael Rennie. Meet Mr. Callaghan stars Derrick DeMarney, no stranger to detective films, in the title role. In this "pilot" for a proposed Callaghan movie series, Slim is required to solve the death of a much-hated rich man. (allmovie.com)

A woman has been sentenced to death by hanging. Her cousin believes she is innocent and he works against time to prove it before she is executed. (imdb)

A murder at a country house centres around the whereabouts of a horde of stolen diamonds and the unmasking of people who are not as they at first seem.