There's this essay by George Orwell called
Revenge Is Sour, and there's a bit that has stayed with me. This is not intended as moralizin'.
It is said that when Mussolini's corpse was exhibited in public, an old woman drew a revolver and fired five shots into it, exclaiming, 'Those are for my five sons!' It is the kind of story that the newspapers make up, but it might be true. I wonder how much satisfaction she got out of those five shots, which, doubtless, she had dreamed years earlier of firing. The condition of her being able to get close enough to Mussolini to shoot at him was that he should be a corpse.
Revenge almost always feels a little too late.