Red truck- I've never heard anything about the key being recovered.
WH said he left ONLY the ignition key, NOT the door key, in the mailbox March 2 morning. Why? Was the truck left unlocked (probably not), maybe AJ had a door key of her own, but odd both keys were not left in the mailbox together, imo.
Maybe it was important for WH to get the key info out there because police later found the truck door key in his hotel room. idk, but it seems odd WH pointed out he only left the "ignition key, not the door key" during the jail interview.
it's possible the truck had a door key, and ignition key. If they ever had to get a new ignition (it's an older truck so very possible) then it would need 2 separate keys. You are assuming that he meant the house's door, but he only gave partial info, as usual. It seems he always throws little tidbits in to the "salad" when he knows that someone has picked up another clue to link him, and he tries to explain away.
My guess is that he still had the truck door key, and someone saw it on his key chain so he had to acknowledge it and give what he thought was a logical explanation. He could have taken her in the van to run to the hotel room to grab the key....
I have thought from day 1 that WH was the person sending the texts to JH. He was not living at home. There were pings by the water because he texted, and tossed it. Remember, he was doing drugs (by his own admission) so it wasn't like he would be sleeping and have a normal person's schedule. He was buying more time with the texts so that he could dispose of the body before they could report her to be missing. Once he felt secure about her body being out of the way, then it was time to turn the case in to a "missing persons" and get LE involved. So he helped them along by planting things here & there since they didn't believe his story the first time around...
LE was on the money when they said they knew her phone was in his room, and this is why suddenly amnesia set in for him. There was no lie he could think of right then to explain away it being there and he knew he was caught. He could explain everything else away, but how could you explain the text telling JH that AJ just wasn't ready to come home yet? There's no way to blame her phone accidentally being dropped it his truck or whatever.....the only thing left was memory loss.
He offered the reward a few hours after he just saw her to her friends. He was pacifying JH that they were looking. IF there was an argument between mom&daughter, then dad could step in and be the "hero" by taking charge and getting her back. He has tried to play the hero-in-action part from the first moment!
All of this is just speculation on my part and MOO.