I'd hate to be the first person to say this because it makes me sound like a snob, but it has to be said: the book was better. I believe everyone will be entitled to their own interpretations, just as Ellroy had been to an unsolved Dahlia murder that inspired his fictional novel (after all, it IS unsolved), but when you attempt to make a film based on a fictional book that was based on true-to-life incidents, you better stay true to the book or at least make sure your interpretation is half as interesting as the original.