@whatthomwatched the title’s got to do with checking it twice, as the police do in the film. That no bad deeds go unpunished. It is a good contrast with few other films with the same Cain novel as source material:
Le dernier tournant (1939)
https://m.imdb.com/title/tt0031222/
Ossessione (1943)
https://m.imdb.com/title/tt0035160/
Jerichow (2008)
https://m.imdb.com/title/tt1224153/

They all are very different in tone and their cultural/periodical context #globalnoir #jamesmcain