Name one.
One flagrant case you read about is that of Randy Seidle of Illinois, and of Herbert Whitlock who is still in prison in a case involving a very flagrant abuse of prosecutorial powers.
"Name one."
They can't.
Remember that during the settling days in the west that horse thieves were hung. The fact that is was very easy to steal a horse but with severe and immeadiate punishment made the crime fairly rare. There is direct coorelation between crime and punishment {if the punishment happens in a timely fashion}.
Additionally, rape was also a capital offense. It too was much rarer than we see in todays world.
As a deterrent, it works 100% of the with the perp.