GP Kunz told us that the baby was his nap buddy which is why (I think) we all assume that they lived and live together. Whether LE in IF searched the Kunz home before the parents returned is not certain. Actually, it has never been brought up but it is a great point to bring up. Thanks.
Unless the body is found and pre-death bone injuries such as skull fractures, knife cuts or gunshot wounds are identified, the COD will never be determined with any accuracy - it is too late for that. That ship has sailed. Even if the killer(s) tell(s) us how the baby died, we still will not know for 100% certainty - see e.g. Reuben Ebron's 'baby drowned in the bath tub story'. But, let us not dwell on the things we may never know.
Let us know this: we do not seek justice for a person, we seek justice as a means to maintain our notions of a civilized society. Nothing we do can ever undo what has been done and the dead do not need justice; society does. DeOrr has no hatred for his killers or any need for retribution. He doesn't need a hole in the ground with a headstone above to rest in peace, he is in eternal peace, joyous and his soul is in ecstasy. Besides, what better resting place than being one with nature in God's great wilderness can anyone ask for?
We may not obtain the justice we seek but we know where DeOrr's soul resides. This will sustain us all.
For now, let's all send our love and forgiveness out to the parents rather than our hate. Pray for them.