Well, because taxpayers, or at least their agent, wrongly imprisoned him for 18 years. How do you value 18 years either way?
Ok, so give him $20 million, with such a rationale. CT taxpayers didn't wrongly imprison him. The City of Hartford, prosecutor and jury did. CT does not have counties. I see no reason this should come out of general state revenues. Also, DNA techniques were lousy back then and are much improved now, so is it fair to say they bungled it so badly?