A huge West Indian guy went berserk in a store my wife managed, threw her against some shelves and tried to wack a can of beans in her head ( she dodged it). The security staff got him outside and gave him a serious beating - about which my wife, to her credit, was disgusted and angry.I wouldn't go to the stake to save people like the Wests, to mention an odious couple who achieved notoriety in the UK; nor the likes of John Wayne Gacey in the states. It's a serious issue, though, that even in the most apparently clear-cut cases, wrongful convictions do occur. I can't think of anything worse a civilised society can do than execute an innocent person.
I don't have any stomach for executing war criminals years after the atrocities, because people can and do change. I would however be all in favour of them having to square up to what they'd done in some appropriate forum. I had great hopes for the truth & reconciliation approach in S Africa. Pity it didn't work better, but it was still their best chance of a stable recovery from the horror that went before.