I'm starting to wonder if maybe DE just wanted to kill someone...? IDK. I definitely lean toward the idea of contacting/interacting with Nicole being his idea (though, with the little we know, it could be ANY which way around, IMO).
Don't know, though, that I think DE is a pedophile, or sexually interested in younger girls, particularly. Maybe it was just what he perceived as neediness/weakness/"imperfection" that drew his attention to Nicole as "an appropriate victim" for him.
One kind of way-out-there scenario I've thought of is that his "perfect murder" plan could have involved finding someone else to draw into the plan...and maybe NK had a neediness, in his view, herself that made HER fit his specs, too. Maybe the plan was to draw her in, first with just relatively casual, this-is-just-a-fantasy talk, gradually moving closer and closer to reality. Like a game...a "secret and special" one. Right down to...let's buy a shovel. Let's choose a weapon. Let's decide how we would lure Nicole out.... I sometimes think maybe he thought of killing NK as well ...having some kind of story (much like some of the scenarios those here who see NK as the "mastermind" have suggested) rigged up to make all this look like her idea and, in his version, put the weapon in her hand....maybe he tried to stop her, etc. (in his prepared story). But something misfired, and he didn't kill NK.... And she's got the Minions blanket and the cleaning supplies that he probably touched without gloves...?
Ah, just an idea. Whatever happened, I can't see how he would think the social media would not be tracked...Maybe he thought he could erase all the incriminating traces, but that seems unlikely.
ETA: I wonder if WalMart video will show both DE and NK on their trips...or did someone get sent in while someone waited in the car...