Although every more or less said it was the parents, I'm now of the belief that not only that they "knew" it wasn't the parents, they put out "false information" to entice Karr. He wasn't in their data base.
As long as folks were still attacking the Ramseys, it put "reasonable doubt" on his side. He could talk about it. He could write about it.
So he gave himself away. Someone fed him false information? He corrected it!! It's going to be the heart on the hand. Best Guess: It was there BEFORE the murder, not after the murder.
good points...