bert's got it. Certainty of getting caught and not being allowed to profit from it is the key.

Severe punishment is useless if the bad guys think they won't get caught. Last time I heard police in our neighboring city, Spokane, weren't investigating burglaries at all. Too shorthanded, they said. So it doesn't matter much what the penalty is there.

If every time someone tried to steal something a mean 19th century schoolteacher jumped up and cracked them across the knuckles with a ruler and made them put it back it'd stop theft a whole lot better than a death sentence that was never enforced.

Only I don't know where to get the schoolteacher...

Clint