Beyond a reasonable doubt is a pretty clear theory of law.
An extraordinary hearing last year ordered by the U.S. Supreme Court gave Davis the rare opportunity to present evidence of his innocence as part of a petition for a new trial. The judge overseeing the hearing ruled that the state's case against Davis "may not be ironclad" and agreed that Davis had raised some doubts about his conviction, but concluded that he had not provided the court with compelling evidence of his innocence and denied the request for a retrial.
Whores til proven otherwise. And they so rarely do.