Mr. Wong, Detective with Boris Karloff. Chinese amateur sleuth Mr. Wong (Boris Karloff) is approached by businessman Sam Dayton (John Hamilton, who was Perry White to George Reeves' Superman) because he feels his life is in danger. The following day Dayton is the victim of a classic "locked room" murder. Dayton's two business partners, Meisel and Wilk, are prime suspects because they have all just signed a tontine amendment to a business venture - in the event any of the three men dies, his interest in the venture reverts to the survivors. Another suspect is Carl Roemer, uncompensated inventor of the chemical involved in the business venture. Over the course of the investigation, Meisel and Wilk both succumb to the same method of murder while Roemer is in police custody. Mr. Wong calmly and pleasantly interviews suspects and discovers evidence, and eventually solves the case.
The film was made by Monogram Pictures, one of the "poverty row" low budget movie production studios. Mr. Wong was a character in a popular series of stories from Collier's Magazine. You can watch this movie in it's entirety on the internet at http://www.archive.org/details/Mr._Wong_Detective, but I'm betting you won't.