[The case for executing the guilty] seems like a separate issue from the fact that the American criminal justice system too often punishes the innocent. I see three main facets of that problem. One is that we don’t provide adequate legal representation to many indigent defendants. The prevailing wisdom seems to be that underfunding public defender officers is somehow “tough on crime” as if railroading innocent people is a close substitute for punishing guilty ones. The second is that we rely heavily on eyewitness testimony even though it’s known to be unreliable, and police departments often don’t seem very interested in improving witness identification procedures. The third is that we give convicts far too little ability to present newly discovered evidence of innocence. But none of this has anything in particular to do with the death penalty. If an innocent man is in prison for a grisly rape/murder based on eyewitness testimony that would be debunked by DNA evidence that wasn’t available at the time of his conviction, that’s terrible even if he’s not being executed.There seems to be an active institutional resistance to the introduction of new information once a verdict has been decided and a sentence has been passed. If the point of the criminal justice system is to mete out actual justice, then it is mighty strange that after an arbitrary moment in time, new information is no longer permitted. Or at least the barrier to new information is abruptly and steeply raised. It also seems to me that the burden of proof abruptly shifts after a verdict has been passed. While in trial, a guilty verdict requires proof beyond a reasonable doubt, but post-verdict, it seems that innocence requires proof beyond a reasonable doubt.
I keep saying "seems" because I must admit that I am not really well-versed in the ins and outs of criminal justice. The two cases I have read the most about (and even here I have not really done all my homework) are those of Cameron Todd Willingham and Troy Davis. In the former case, independent forensic analysis called into question the forensic methods used to reach the guilty verdict, but the new forensic report was ignored. The latter case relied heavily on eye-witness testimony, seven-ninths of which was later recanted. Both of these cases are examples where, at least post-conviction if not pre-, the evidence of guilt was not sufficient to surmount reasonable doubt. If the same burden of proof applied after conviction as before, these two men would still be alive.
Getting back to Yglesias' post, it is perhaps a shame that so many bleeding heart types like myself get so riled up about the death penalty when there are likely many more innocent people languishing in prison than there are innocent people awaiting execution. I agree with this, and recognize it as an unfortunate cognitive bias. On the other hand, it's hard to see it happening any other way. Ritualistic state killing is so conspicuous that it probably must come first in reform efforts. I rest somewhat assured that the liberal appetite for justice will remain unsatiated after exhausting the ample low-hanging fruit of state-sanctioned injustice.