I believe the fact that he buried Chelsea, will speak of his sanity. A crazy person doesn't know they're doing wrong and wouldn't even think of to bury a victim.
Besides, I feel his ALLEGED bi-polar condition is just a ruse. During the Groene case, we got the look into the inside of one of these sexual predators. The murderer blogged about it. Joseph Duncan learned to use the system and APPEAR to be normal, yet planning his next ................................whatever you would call it. He killed at will, and saved for another day a murder victim until he was done with them.
What I've seen in this case, two different doctors having entirely different diagnosis, to me, is the sign of a sociopath's work. He acts the way he is supposed to or the way EXPECTED, and then does whatever he wants, because he feels NOTHING, no remorse, no humanity, no heart!,.....he is just out for HIMSELF.
I could be wrong and I do not have any credentials to speak of, just IMHO.
FWIW,
fran