Question: What is the name of the American serial killer of the 19th century on which the 1974 psychological horror novel by Robert Bloch is based?
Sentence (from "American Gothic (novel)"): American Gothic is a 1974 psychological horror novel by American writer Robert Bloch, a fictionalized portrayal of real life serial killer H. H. Holmes, who is renamed "G. Gordon Gregg" for the story.
Relevant evidence: Yes