"The King Murder" is available on DVD from Alpha Video. Like most of Alpha's films, this one has a rather rough print--a bit blurry (looking as if copied from a videotape or just a very used print) and with poor sound (there's too much background hiss). Unfortunately, this is likely the only way you'll find the film so you'll need to accept it, warts and all. Fortunately, as the film progresses, the sound quality at least improves though at the end it suddenly became worse.
This story was apparently based on a famous murder case of the era involving a blackmailer named Dot King. Interestingly, the studio (Universal) didn't disguise this very well, naming the character Miriam King.
Miriam has made a career out of seducing rich married men. Then, once she has incriminating information, she blackmails them into paying her not to produce this information to their wives. After her latest shakedown, Miriam ends up dead and the police are trying to figure out what happened. It isn't easy, as she's gathered a lot of enemies over the years.
Conway Tearle plays Detective Barton--the man assigned to work on this murder case. Interestingly, despite the subject matter being rather salacious and the recentness of the actual murder, the film did NOT seem exploitational in the least. Likewise, it was handled in a quiet, cerebral fashion and the overall film was far better than I'd expected--especially since it was from tiny-budget Chesterfield Productions. My only complaint, and it's a minor one, is that the pawn broker seemed incredibly broadly portrayed---extremely Jewish--most likely in keeping with stereotypes of the day. Worth seeing even with the lousy print.