I wish reviewers would stop saying that this film is based on the Black Dahlia murder when it isn't. Actually Elizabeth Smart was nick-named the 'Black Dahlia' after a suitor got the name of the film wrong, and it stuck. The Blue Dahlia is a place, not a person. Rant over.
I think this is probably the best of the 3 films I have seen with Lake and Ladd. Lake is astoundingly beautiful, Ladd is tantalisingly handsome, add in some dark scenes, some romance, some murder and you pretty much have this (and any other film noir that you would care to mention).
Ladd returns home from war early only to find that his alcoholic wife has been having an affair with a male friend. *SPOILERS* The wife is murdered the same night, and of course Ladd is the prime suspect (when we all know he didn't do it because he was chatting up Lake at the time).
I love these tense plots where the audience know the truth and the police don't, and there is no proof to save the hero. It keeps you glued to the seat.
Great movie, worth a watch for one of the greatest noir pairings ever.