Synopsis by Hal Erickson
Invisible Killer was the second effort from Producers Distributing Corporation, the enterprising poverty-row movie firm that would eventually matriculate into PRC Pictures. Based on Carter Wayne's novel Murder for Millions, the story concerns a trio of mysterious murders, each committed in the same bizarre fashion. Girl reporter Sue (Grace Bradley) and her police-officer boyfriend Jerry (Roland Drew) suspect that all three killings were perpetrated by the same murderer (duh!), and set about to prove it. The gimmick is a tiny poison pellet concealed in a telephone receiver, which is released into the air when the victim-to-be answers the phone. But knowing how it's done isn't quite the same thing as knowing who, and that's what Sue and Jerry want to find out.
investigation, murder, poison, reporter, telephone, boyfriend, girlfriend