The story is adapted from "The Land of Terror" story in Doc Savage Magazine (Street & Smith Publications, 1933 series) v1#2 (April 1933) by Lester Dent [as Kenneth Robeson].
The feature continues in Doc Savage Comics (Street and Smith, 1940 series) #v1#1 (1) ([April 17] 1940).
A house advertisement for Doc Savage Comics (Street and Smith, 1940 series) #v1#1 (1) ([April 17] 1940), with a full-page art panel that continues from the Doc Savage story.
The murderer is not revealed; this leads to a contest on the inside-back cover
The Iron Munro comic stories were inspired/based on editor John W. Campbell's Arn Munro short stories in the Astounding Science-Fiction (Street and Smith, 1938 series) pulp.