The Atlanta Child Murders
From the time that Wayne Williams was convicted, doubts arose about his guilt. Many black Atlantans felt that the government had manufactured the evidence just to get the case closed. While there are a number of issues in the government's case that are controversial, the fact is that the prosecutors, especially the FBI, believed that Williams was guilty.
Did the government play fair and square during the trial? No, but that does not seem to be unusual, because prosecution is about winning, not about justice or fairness in the abstract. The facts are that no one ever witnessed Wayne Williams killing or abducting anyone.
The most important evidence against him was highly technical fiber evidence that only experts could judge. Any jury presented with the huge amount of fiber evidence in the Williams case and the government's experts testifying to its veracity would be likely to give it credence.
Unfortunately, Wayne Williams was his own worst enemy. He never came up with a credible reason for being on the Jackson Parkway bridge in the early hours of the morning and his alibis were easily destroyed, but it didn't mean that he was guilty of murder.