What is symbolic in a good man is hard to find?

In a Good Man is Hard to Find there is many instances of irony. Verbal irony starts very early in the story. One of the first things the grandmother says is "I wouldn't take my children in any direction with a criminal aloose in it. I couldn't answer to my consicience if I did." And then later she takes her family down the road that gets them in a car crash and soon killed off by The Misfit.