"Also, you mean to say he stayed in that house and drafted that note AFTER he killed JonBenet?"
I think: Someone (maybe this perfert) entered the house when the family was at the party and waited until they were asleep. He killed JB and left. Patsy found the body in the night, assumed husband or a son killed her, so wrote the LONG kidnap letter to throw suspiciaion away from her family.
That makes no sense, I still say it was Patsy