Kansas v. Marsh

I was reading this article by Dahlia Lithwick and started to research some about what the Supreme Court has said on the issue. As per usual, Scalia had some rather interesting things to say, but his last paragraph of dissent is what caught my eye. He wrote,

Like other human institutions, courts and juries are not perfect. One cannot have a system of criminal punishment without accepting the possibility that someone will be punished mistakenly. That is a truism, not a revelation. But with regard to the punishment of death int he current American system, that possibility has been reduced to an insignificant minimum...The American people have determined that the good to be derived from capital punishment--in deterrence, and perhaps most of all in the meting out of condign justice for horrible crimes--outweighs the risk of error.

Unless I'm mistaken, isn't he saying that, even though we may kill innocents (those "insignificant minimums") it is OK so long as the majority are satiated? Isn't that exactly what our system of government is supposed to protect the innocent from? Maybe I misread it. I will read it again...but that was my first reaction.