I didn't read the whole thread, and, frankly, I don't care whether you think that even notorious (American-backed, might I add) dictators go nutso on their own brothers (and sisters), even if you're prepared to argue the point. [Seriously, I don't mean any disrespect; I've read the first page of 50 posts.]
I shall always have something in response, and so, yadda-yadda-yadda.
The death penalty, also known as capital punishment, is the execution of a convicted prisoner authorized by the state as punitive measures for capital offences.
The argument breaks down to this, or something that resembles this, the death penalty is supposed to deter murderers (which I believe is just utter bullspit, because, with or without it, in the grand scheme of things, "shit happens"); and it is retribution to those who wrong (no, I don't believe this is a fair reason to take another human being's life - leave this to gangs, mobsters, and such people, but not the freaking system/State).
Also, having accidentally executed a 'prisoner', one cannot simply undo such an act against human rights and justice; thus, the risk of accidental execution of innocents precludes the use of this radical method to deal with crims (but America doesn't care, nor does China, or any 'revolutionary' country for that matter, like Cuba).
Also, what the hell is cruel and unusual punishment? I mean, take the recent examples of well-known executions, those of Saddam Hussein and his fellows - what the hell is choking the crap out of these people going to do; what is decapitating Barzan Ibrahim al-Tikriti going to achieve?
This is not justice; it is the State committing a crime that one could, and should, liken to those committed by these unspeakable people.
That said, I did not, do not, and shall not* support the death penalty
*That's how I'd like to see myself in the future, I suppose.