This month’s Cato Unbound is especially interesting to me because it discusses how to integrate new facts into an old public policy debate: Now that we (sometimes) have DNA evidence, what does it tell us about our capital punishment system?
One answer, of course, is that it doesn’t tell us anything. If you have a moral objection to the death penalty, adding certainty to a guilty verdict won’t move you at all. Or, if you’ve said all along that you can tolerate a given level of erroneous executions, you shouldn’t be terribly upset when a few of them are identified — to you, the death penalty is still very much doing its job and still very much worth the price. As long as there aren’t too many of them, the system is working.
But in between these two camps of purists, there’s still a lot of room for debate. In the cases where it’s available, DNA evidence might show that we are making an unacceptably high number of mistakes. And this might lead to inferences about the other cases, the ones where DNA isn’t available. There are reasons to question how solid these inferences are, but we might still learn some lessons about improving the criminal justice system. Would we still want a death penalty? Now that’s an interesting question.
Anyway, I’d suggest you all check it out. Feel free to comment below.
 Note that DNA-to-capital-punishment is a thorny issue in ways that, say, DNA-to-rape-conviction is not. As opposed to capital cases, DNA is very often present for rapes, and anyway, absolutely no one is arguing that rape is morally acceptable.