Since 1973 there have been over 130 prisoners released from death row because they were found to be innocent. If the state is going to kill someone they need to get it right.
There have also been at least 5-10 cases I can think of off the top of my head where there were serious deep problems with the case but the person was executed anyway. The most recent case in which an probably innocent man was executed was Cameron Todd Willingham.
If you think that the possibility of executing innocent people is just some sort of "smokescreen argument" then you're just giving credence to what Olivant wrote upthread.
"When the snows fall and the white winds blow, the lone wolf dies but the pack survives."
Winter is Coming
Now this is the Law of the Jungle—as old and as true as the sky; And the wolf that shall keep it may prosper, but the wolf that shall break it must die.
As the creeper that girdles the tree-trunk, the Law runneth forward and back; For the strength of the Pack is the Wolf, and the strength of the Wolf is the Pack.
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