I read an article in the paper about a fellow who was finally exonerated of a capital crime by DNA evidence (details here). Apparently there were many inconsistencies and other indicators of a wrongful conviction, but the new evidence cliched it and resulted in a pardon for the accused (after serving 17+ years). Now for the scary part--a sheriff's deputy is quoted saying "I feel as strongly about the case as I did back then," thinking the accused was involved.

I have seen this attitude in numerous instances over the years. Some law enforcement people (police and prosecutors) seem to be absolutely unable to accept the possibility that they are/were mistaken in feeling/thinking/knowing so-and-so did it. Sometimes it seems that even if the actual perpetrator, the victim, and God himself appeared with positive physical proof that the suspect could not possibly have done the crime, these impeccable crime-fighters would cling with unshakable certainty to the notion that he still did it anyway.

I know that dealing with the criminal element exposes one to some nasty stuff, and it's understandable--and maybe desirable--that law enforcement personnel be generally skeptical about reversals of convictions. But c'mon, even in the face of essentially incontrovertible evidence? We still hear pat lines like "The system worked the way it's supposed to" and "I see no reason to re-open the case." It makes me cringe.

What makes a supposedly rational person flat out ignore cold, hard facts in these situations?