If I murder you, that is a sin. Once upon a time no one would argue with the death penalty being appropriate. Now things have changed. The murderer is sick and needs understanding. Think what a traumatic experience it was to commit a murder! Poor lamb, they say. And lawyers like Clive Stafford Smith suggest that since a life has already been lost, it is not worth spoiling another too - namely that of the murderer.

This shifting in the "cultural norm" of morality (not God's law, which is unchanging, but the perception of what is generally agreed amongst people) dictates the stories we can tell. Think of the most recent adaptation of Murder on the Orient Express. It's a simple story: a child was brutally killed and the murderer got away with it. Everyone who loved the child boards the same train as the killer and they murder him. In the original story, Poirot is sympathetic and holds the truth of the death a secret. It might be rough justice, but it is justice nonetheless and if the police cannot fathom who did it, he will not tell them.