go back and see if there had been an arrest warrant back in 1994 for the perp so they could identify the guy who had served the prison sentences. The DOJ said if if he wished to gain further information, he would need to hire an attorney and pursue the matter in court.

As for the original cops, I remember my brother telling me 17 years ago how they admitted they had screwed up. They had a photo of the guy, but did not bring it with them at the time they knocked on his door. The perp was apparently relaxed and convincing that the roommate was who they wanted.