I think I understand what you are asking. I'll try to explain as best I can.
Only with certain crimes can a person get the DP. It is up to the jury (in most cases) to decide if that person will be put to death or get life in prison. If that person gets the DP, it will take many years to actually be put to death. Every state is different. I live in Az and I was researching the DP because of a certain local case (
http://www.abc15.com/content/news/southeastvalley/chandler/story/Chandler-dad-faces-murder-charge-after-baby/h7BN7peoZE2LGDznbwW-Ng.cspx ) ( another equally disturbing case) In Az, the average wait time from sentencing to death is about 12 years. I've tried to find statistics for NC and have not been able to find them. I have read somewhere that is costs more money for someone to be housed and put to death than it is for some to be in prison for life. Yes, our taxes pay for this. IMO, my taxes are well spent to put these type of people death. Also in Az and I think all other states, when someone is on death row they are housed in a different area than the other criminals. IMO, people like MAM should be put out there in the general population. Even criminals have a certain "code" and would take care of MAM themselves.
I hope I didn't offend anyone with my opinion on the DP. That is not my intent, it's just my personal opinion.