How exceptional does something have to be before it ckunts as "unusual"? Sooner or later the minority of countries which still have Capital Punishment will drop it. And eventually it'll be so unusual that the US Constitution ban on "cruel and unusual puinishment" will kick in.
And even now I'm pretty sure that killing somebody after keeping them in jail for 19 years for a crime they may have committed when they were 17 is definitely an extremely unusual thing to do in any part of the world, including China, Saudi Arabia and Afghanistan.
And I don't think you'd find that many people, even among supporters of capital punishment who wouldn't think it was cruel - even if they believed the cruelty was justified.