Murder At 3AM (1953)

aka: Murder At 3A.M.

Dennis Price stars as Inspector Lawton of Scotland Yard. A series of late-night murders is baffling the police and as the murders continue, each fresh clue ends up in a dead end. Sensing he is on the verge of a breakthrough, Lawton is horrified to discover that new evidence pinpoints his sister’s fiancé as the murder. Also stars Peggy Evans and Rex Garner.