An assumption that I see a lot is this; "If Coy were innocent, Jane Doe would have come forward by now."
It's a nice thought, that someone with a horrible secret would be eager to get it off their chest, but it defies human nature. We hide our lies, as a recent exoneration from Ohio illustrates. Ricky Jackson just earned the dubious distinction of having served the longest prison sentence before exoneration.
He served 39 years for a murder he didn't commit, because that's how long it took for the (then twelve year-old) witness to admit that he had lied. Two co-defendants were also exonerated.
In 1975, the boy's testimony was detailed and convincing; it wasn't until he was in his 50's that he admitted the lie, and told his pastor that it had hung over his life like a shadow. He testified this November to free Jackson, and from the article (linked below) it sounds like prosecutors tried to convince Jackson to plead guilty at the beginning of the hearing, in exchange for certain release.
He refused, and won his freedom anyway.
Sometimes this fight seems endless and hopeless; Please, keep in mind that the situation can change at any moment. In the Cleveland case there was no reason to think that, after so many years, one witness would come forward to set the record straight. It was a miracle that it happened, and that's what we hope and pray for in Coy's case.