bbm
Or worse...he may have been dragged along with the uncle for the body dumping. Gary Ridgway (Green River Killer) took his young son with him on at least two occasions when he killed and/or "buried" his victims.
I sure hope that that didn't happen, but, chances are that he may know something. It may take weeks of folks gently working with him to bring it out, and they don't want family members in a position to contaminate his memories.