This is an interesting article about the Cameron Todd Willingham case - a man who was convicted and executed for allegedly setting fire to his home, killing his three children.
So if, as appears to be the case, this was the "execution of a legally and factually innocent person," does that change any opinions on the propriety of the death penalty?
Personally, I think anyone who seriously believes none of those executed are innocent is willfully deluded. Thus the policy discussion ought to be whether we as a society think putting certain individuals to death is of such importance to society that it is worth the "collateral damage" of innocents being executed. I don't think it is. I think lifetime incarceration is perfectly adequate to serve society's interests with regard to any crime.