In most civilised countries, the death penalty was abolished in defiance of popular opinion. As those societies absorb the reality that they manage just as well without it, popular support diminishes. This is the case in the UK, for instance, where support was once around 70 per cent and is now down to about 50 per cent. (Some stats here.)

In the US, capital punishment was de facto abolished after Furman v Georgia in 1972, and put back in play with Gregg v Georgia in 1976. Gary Gilmore was the first to take advantage, using it to achieve his suicide by proxy. This makes the US the only country in the world and in history, as far as I can ascertain, to have achieved abolition and then gone backwards (as I would describe that direction of travel).