How tragic. Reminds me of John List.
Oddly worded for a confession note, and extra-odd that there were duplicate copies. Unless they can tie him to the crime with physical evidence, or he can pass a polygraph while confessing he did it, I think they should be seriously investigating the possibility that somebody else did it and put him up to writing the confession notes, by threatening him and/or other close relatives of his with the same treatment.
Who writes a pair of identical confession notes and leaves them in the same place? And if what’s quoted in the article is the full text of the notes, it gives no hint of a reason for the murders, not even an irrational one. Just sounds suspiciously as if designed to point suspicion at him, and accomplish nothing else, and he hardly needed to leave a note to do that — he could just have turned himself in, or if he was originally planning to kill himself, he could have made a 911 call to get his confession recorded.