Which is why there are no murders in states with a death penalty.
https://en.wikipedia.org/wiki/Mothers_Against_Drunk_Driving
The claim they lowered drunk driving deaths by 1/2. I have no easy way to verify that but if true it certainly suggests people's behavior can be changed
This does not discourage drunk driving as much as you would think. It does remove a lot of the drunk drivers from the road by force, however.
Edit: Claiming credit moreso than flawed statistics, although both are highly questionable.