Because your 2nd paragraph is delerious.
Perhaps it is a stretch...however i don't think it is beyond the realm of possibility that he could have somehow picked up on details of the case that are not known to the general public. For instance, information could have inadvertantly been supplied to him during the emailings that were alluded to earlier in the thread.
And phony confessions, believe it or not, are quite common in high profile cases.