I don't have a problem with it in theory. If someone is tried and convicted for a horrible murder or terrible crime against a child, I have NO problem with killing them.
The problem, however, is that our criminal justice system is not perfect. We still sometimes convict the "wrong guy" and since the death penalty is irreversible, I am very concerned about its use in society.
Check out this story below. If this guy had been convicted, given the death penalty, and then executed how would y'all feel? And the fact is, if he HAD been executed, there would have been no effort to re-investigate his conviction. Because he WASN'T executed: a) he is able to walk free again; and b) we as a society have the opportunity to look for the REAL killer!
Masters: Cop's big ego stole half my life - CNN.com