Leaving political and ethical reasons aside – and they are legion – there is a major practical problem for those that want to reintroduce the death penalty. Namely me, and others like me, who are implacably opposed to the death penalty.
If I were on jury duty on a capital case I would under no circumstances pass a guilty verdict on the man or woman in the dock, even if I thought they were guilty.
Under no circumstances would I be a willing party to a murder. Especially not the most vile murder I can think off; to kill someone in a fit of anger is bad enough, to sit down and decide it is a good idea over a matter of months is downright evil.
It would not take many people like myself to mean that a serious proportion of capital case juries were incapable of returning unanimous decisions. One member out of twelve could kill (heh) the whole enterprise of returning people to the hangman’s noose.
Seeding evey jury with someone like myself would not even be necessary, even a small fraction of a few high profile capital cases would be enough to embarass the whole project. It seems the whole death policy “debate” is more about willy-waving and tribalism than the demands of criminal justice.
UPDATE: Mr Civil Libertarian informs me in the comments that 10-2 majorityish decisions are permissible for conviction by jury. This alters the make up of an incalcitrant jury meaning three of me would be needed to sink a case as things stand – still possible, but not nearly as likely. However, I find it unlikely any capital punishment bill would not be forced to include the proviso that conviction be unanimous, so my point still stands, mostly.