It seems the first season of True Detective was based on an actual case. VICE covers the incident in the below video.
In my opinion, the two men in prison may be innocent. I think they were crazy religious and confessed to crimes they didn't commit. After all, there's no victims as the two boys recanted and said they lied. There was also no evidence recovered to suggest anything they said was true. This would be a case of "Satanic Panic". The police appeared to be too ignorant to realize the men were not telling the truth and that none of this happened. I really blame the police in this. They should have realized that when they couldn't find any evidence of a crime that the easiest explanation was that the men were troubled in the head and need psychological help. But that's inbred, backwater "deep south" for you.