This is a hard question. It gets to questions of morals very quickly and it is very hard to debate people over morals. There is one side that thinks killing is an appropriate punishment for some crimes and another that doesn't. Little constructive debate can happen around this line. It is much like the abortion debate in this way.
As a practical matter, I personally believe it is almost impossible to implement a state sanctioned death penalty without executing innocent people. Moreover, life and death decisions are handed to people with political power which automatically corrupts their judgment.
I actually can sympathize with some of the positive cases for the death penalty. It has a strong theoretical appeal but I find it impossible to support practically when I think through the implications of any implementation.
I agree it's a hard question. The USA could vote out the death penalty at any time, it's not baked into the constitution. But the USA doesn't, so we have to accept the democratic judgment.
I do think it's literally impossible to have a death penalty without killing innocents. If you look at the stream of criminal convictions that get reversed by appellate courts on a daily basis, combined with all the exonerations handed down to deathrow defendants, it is clear a guarantee of guilt is impossible.
And bear in mind, that reversal of a conviction is usually only possible if there was a trial. Those who enter guilty pleas are often exempt. And 90%+ of defendants enter guilty pleas for a host of reasons. I think Trump's NY judge even commented recently that Cohen entry of a guilty plea wasn't evidence of his guilt (i.e. you might plead guilty and be innocent).
Having spent a lot of time in the justice system, it's clear criminal trial courts don't have the resources to ensure fair verdicts regularly, and don't have high-quality staff to run them.
IMO, no, because killing someone can't be undone. It's a tragedy when someone innocent is sent to prison. Killing someone - and possibly someone innocent - is just unimaginable.
