in the last 6 months, i've read about 5 guys who did lots of time for murder and 1 for rape all of whom were PROVEN not to have done it after spending 10 years. they could have easily been put to death for something they didn't do. i do not believe one can ever know for absolutely sure what another person did unless you are there when it happens or it is clearly caught on camera.
besides, what about people who truly are remorseful? there are some, you know.
and btw, i've personally known plenty of people who were told they would absolutely DIE if they continued with certain things and it sure didn't stop them or even slow them down. so i'd have to say if you're an addict or a compulsive person, knowing you could die isn't a deterent.
and here's one lots of people disagree with, but that's okay 'cause it's only my opinion. i believe that killing someone puts out a message that killing is okay. if our coutry as a whole doesn't believe that life is sacred, why should individuals believe any differently?