The Invisible Killer is a 1939 English-language Mystery film. Reporter Sue Walker has too much inside information on the local gambling rackets to suit her sweetheart, Detective Lieutenant Jerry Brown, chief of the police Homicide Squad. When the call comes in that there has been a killing at Lefty Ross' place, a notorious gambling joint, Jerry is peeved when Sue beats him there. He discovers that gambler Jimmy Clark was killed as he answered a telephone call, and his body is riddled with bullets but Jerry can't find any weapon. Sue is amazed to Gloria Cunningham there. Gloria's father is one of the town's leading reformers and she is engaged to District Attorney Richard Sutton. Ross decides to give Sutton all the information he needs and makes an appointment to go to Sutton's home. Once there, Ross is called to the telephone before he can give any information, and is killed in the same mysterious manner as Jimmy Clark. The only people aware of the appointment were Sutton's secretary, Tyler, Gloria and her reformer father, and Sue Walker, who was tipped off by Sutton's butler. There are some killings before Jerry gets the case solved, and figures out who, among the suspects, is behind the Invisible Killings. Written by Les Adams. The invisible killer features Grace Bradley in the lead role along with an ensemble cast including Roland Drew, William Newell, Alex Callam, Frank Coletti, Sidney Grayler and Crane Whitley. It was released on 14th November 1939.