As others have said, the purpose of prison is to protect society. There are a lot of punishments aimed at reform, but prison isn't one of them. In fact, the rate of re-offending is quite high, which is why for less serious crimes, some sort of control order or rehabilitation is sometimes favoured. It's why Lindsay Lohan has been to rehab so many times, really As to why they didn't 'arrange' his death: people in Western societies are generally fairly happy about the fact they are "free". In the Us especially, it's supposed to be the home of the free. You cannot have a free society when governments or prison guards are secretly arranging the execution of prisoners at will. It's simply too arbitrary. Either you have a proper death penalty and death row policy, or you don't. There's absolutely no room for the arbitrary, secret execution of prisoners unless you want to forgo your freedoms and admit that you live in a country that Obama and Bush describe as anti-democratic, such as Iraq or Iran. There would be outrage if an innocent person was put in jail without a trial and then arbitrarily executed, and there absolutely should be. The justice system doesn't just protect criminals, it protects everyone. It fails at times, sure. But in general, it's a hell of a lot better than living in a country where women are stoned to death for refusing a forced marriage, or where you can be tortured for the colour of your skin. Also, as others have said, the point of prison is punishment and to keep offenders off the street. If Castro is in prison for life, he can't re-offend. If he's dead, there's always the risk that he will become a martyr for sick bastards who aspire to commit the same crime. There's a perverse glory in being executed that the vast majority of murderers and rapists simply don't deserve.