But what I was suggesting was that a pardon does not free the state, any more than any other party, from liability if the conviction was in error.
However, from what I’ve read in the news - there are two types of convictions of innocent persons - ones where the evidence (as known at the time) showed the party to be guilty; and where the police or prosecutors ignored, suppressed, or through gross negligence failed to produce evidence that might prove innocence. The latter would likely be grounds for civil liability.
A number of people were convicted of rape based on possibly questionable evidence at the time that in the last 20 years have been freed due to further analysis of DNA evidence at the scene. This would be an example of new evidence coming to light.
What’s not clear to me is what happens when a key witness recants. One school of thought I’ve read says that by now having two version of the truth, and admitting perjury, the key witness’s new version cannot be believed so things should not change. This is obviously not necessarily true. Presumably, their original testimony is equally dubious.
Of course (insert snide politician/lawyer joke here) when DNA evidence became affordable for a while around 2000 a number of state prosecution departments sought to limit the ability of convicted criminals to have DNA evidence tested with the new technology, with laws or rules limiting such access.