Not knowing any of the main players in this case One thing that intially struck me about RD is in one of the tv interviews with him he spoke of GS in past tense , something like "he was a good kid" and that was 1 week after GS went missing. So, there's that. And I keep thinking I've seen a crime movie that had a helpful neighbor that eventually became the perp, can not remember the name of the movie. That said at first I usually suspect just about everyone that could have had something to do with it and then eliminate as time goes along. I've been very wrong about many individuals in recent cases and am in process of recalibration of my hinky/guilty meters so my false positives hopefully decrease over time.
Edit to add this article which quotes his referral to GS in past tense,
Neighbor of missing 11-year-old Gannon Stauch says surveillance video shows boy leave home with female relative