I've tried keeping-up on the threads but haven't been entirely successful; therefore, I don't know if the quote below has been posted/discussed. Thought this was a good spot to put it, w/ apologies if it's elsewhere already:
John Karr had disappeared after his release from jail in 2001. Karr, who relatives said had long spoken of a fascination with the Ramsey case, told his father at the time that he was being held for investigation of murdering the girl.
Source
Aha, a record of having 'confessed' to this crime years ago...quite telling, IMO, if it's true.