Editor’s note: While each of these columns is written to stand alone in the series, you can read part 1 here, 2 here and 3 here.

To this point in our series on capital punishment, we saw that retribution (rather than rehabilitation, incapacitation, deterrence, or symbolism) is both the only valid reason for executing murderers and also an adequate reason for doing so. But, of course, the other side hasn’t yet responded. Their objections fall roughly into three categories: practical, conceptual, or religious. 

Practical Objection 1: It’s unacceptable to execute innocent people.

I agree.

Although any legal system assumes some danger of wrongful convictions, the obvious differences between capital punishment and our other forms of punishment are irreversibility and completeness. Even though all penalties (other than fines) take away things that cannot be returned (time, reputation, relationships, freedom), at least the loss from other punishments is only partial. Execution is total and permanent. 

As death-row acquittals have shown, even the plodding deliberation of our legal process with all of its safeguards and evidentiary standards is not enough to guarantee that no innocent people get executed. This is troubling, indeed, and it’s useful to see why the two most common responses fail. 

One attempt begins by noting that we bias our system overwhelmingly in favor of the accused. He need not incriminate himself. He is entitled to representation. If convicted, he may avail himself of a ludicrously thorough system of appeals. And the main bias in favor of the accused is his presumption of innocence. Though such safeguards are set even higher for execution, the chance of error is nonetheless real. Merely reducing the chance of injustice on this issue is not enough. 

The other attempt describes us as being in a “war against crime,” and asserts that all wars entail “collateral damage” to undeserving victims. The problem with this analogy is that the differences between the pressures of fluid battlefield situations and the capital process are so vast that the analogy becomes useless.

The justification for killing the enemy when doing so entails either the chance or the certainty that noncombatants will be killed comes from the principle of “double effect.” We would avoid harming the innocent if we could, but if practical factors prevent it, we accept the tragedy so long as it is still less than the good accomplished by killing the known bad guys. People often use the medical analogy of cutting off a leg to save the body or killing a few healthy cells along with the cancerous ones. The problem with this is it doesn’t apply to the single individual isolated within a jail posing no imminent threat to anyone. Also, since the only thing justifying killing the innocent would be the certainty of also killing the dangerous, not knowing for sure which one stands before us renders the principle of double effect unhelpful. Also, the protection of other citizens cannot be used because the alternative is LIPWPP, not release, for a given convict. 

So if these replies don’t work, how can I respond, especially since I don’t accept the oft-used deterrence argument? (See parts 2-3.) Well, it’s because I believe we can eliminate such mistakes by having two different standards of certainty. Though guilt beyond a reasonable doubt is already a hefty presumption favoring the accused, it’s clearly not enough to avoid all errors. Nor am I interested in raising it for conviction because that would mean acquitting more offenders. But why not a higher standard for sentencing?

There are two different kinds of capital cases: those with some doubt, but not a reasonable doubt, and those with no doubt at all. If we executed only those people who are guilty beyond any doubt, this objection evaporates. Thus, juries in capital cases would return one of three verdicts: not guilty, guilty beyond a reasonable doubt, and guilty beyond any doubt. Regardless of aggravating circumstances, only those in the third category would be eligible for the death penalty. Legislators will doubtless need to more precisely define this new standard, but in principle I’m confident a court can recognize cases that are beyond mistakenness. As an example, consider the case of Timothy McVeigh. People rightly worry that some capital convicts are innocent, but no one worries that he was one of them.  Continued...