The police arrest a man climbing over the wall of a cemetery after midnight. He claims that he is being blackmailed and is following instructions he received by mail to leave $1000 on a certain grave. It turns out that he's not the only one who got a blackmail letter from the same person--calling himself "The Black Panther"--and it also turns out that all the recipients are connected to an opera company.
as Police Commissioner Thatcher Colt
as Anthony 'Tony' Abbot (as Ricki Vallin)
as Everett P. Digberry
as District Attorney Bill Dougherty
as Miss Spencer
as Capt. Edgar Walters / Frank Galloway
as Nina Politza
as Enrico Lombardi
as Police Captain Mike Flynn
as Officer Murphy
as Police Captain Tom Henry
as Samuel Wilkins
as Antonio Spogucci (as Joseph M. De Villard)
as Guiseppe Bartarelli (as Jack Vanaire)
as John Martin George (as William Castello)
as Officer Lou Levinsky (as Harry Clarke)
as Apartment Manager (as Lou LeRoy)
as Nicodemus J. Brown
as Petunia
as Coroner
as Joe Morgan
as Police Sergeant Flanagan (as Casey McGregor)
as Hotel Manager Stevens
as Lombardi's Police Escort (uncredited)
