http://www.theguardian.com/world/2014/apr/28/death-penalty-study-4-percent-defendants-innocent
This alone should be reason enough not to have the death penalty legal.
I dont believe it is ever acceptable to execute an innocent person. I also dont believe our justice system will ever be perfect in that regard. Therefore i dont believe the death penalty should be legal,as much as some of the most guilty might deserve it. Not as a merciful act towards the worst among us, but because of the innocents that do get caught up in the system.
This sums up my feelings pretty well too. And I'm sure 4% is a very conservative number.
Also says something when you are in such a minority that you have trouble finding someone that will let you buy the drugs necessary.