What if this was a fight?
Why would MR cover it up?
Why have we not seen any video of Dad in Walmart?
Good question. Wish I knew.
If MR & Dylan began to argue on the way to dad's place, MR may have decided to drive somewhere they could fight without attracting any attention.
MR certainly wouldn't want to admit he beat his child to death imo.
If LE don't find any signs of a struggle in MR's truck, this could be why.