How many letters does the top answer for “author of double indemnity” have?

The most common answer is cain (4 letters).

Crossword clue: author of double indemnity

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

cain 4 letters wd-fact-v3

(Old Testament) Cain and Abel were the first children of Adam and Eve born after the Fall of Man; Cain killed Abel out o

wilder 6 letters wd-fact-v3

United States filmmaker (born in Austria) whose dark humor infused many of the films he made (1906-2002)

author of the double 67% similar → dostoyevsky

author of double star 50% similar → heinlein

author of the double-bass 50% similar → suskind

author of the double helix 50% similar → watson

wrote double indemnity 50% similar → cain, wilder