I'm not saying that he killed all the children; there is no question that murders were attributed to him falsely. Nor am I saying he got a fair trial - he didn't. But those two facts alone does not remove the fact that he was guilty of at least the two murders for which he was convicted, if not several others. As someone who started researching this years ago - with complete certainty that Williams was railroaded - there is no doubt that Williams fits the psychological profile of a serial killer and that the forensic evidence indisputably linked to him (which isn't much but still unassailable) correctly tags him as guilty of murder. No "evidence" brought in the past 25 years has withstood the tests of accepted science (even in the pre-Daubert era) or FR 702 (even in the post-Daubert era.) Unfortunately politics played such a role in his conviction that it is impossible for many people believe this, and I am sure I will hear from a few of them on this board.
Two things that don't merit any discussion: First, the law enforcement person who supports the hypothesis that Williams was/is innocent; folks, he ASSASSINATED his political rival with hired thugs. Second, anyone who thinks "the Klan" had anything to do with this credits that organization with more craft and subtlety than can be supported by the remotest acquaintance with reality. They're the Klan, people, not the Impossible Mission Force.
Here are the documents, read 'em for yourself. And yes, it is the FBI, but believe it or not the 1980s was the only period in American history that the FBI really was a law enforcement organization:
http://foia.fbi.gov/foiaindex/atlanta.htm