Still stuck on the "door key" comment (sorry, details matter, and this one has me seriously confused). I actually woke up this morning thinking about it, rolled over in bed, and randomly queried Hubby. "Hey, is there ANY scenario in which you would need 2 separate keys to a vehicle, one to open the door and one to start the ignition?". After looking at me like I'd grown an extra eye, he replied, "Well, if the truck was stolen at some point, I guess so. Or if it had maybe been in an accident and the door was replaced? Or....ummm....if at some point the ignition was replaced?".
Hmmmm. Okay, so this morning I go back to the transcript. WH is a word salad artiste, but he certainly SEEMS to be connecting both keys to the truck. Maybe he's NOT talking about the house key like I assumed. Maybe he's saying exactly what he appears to be saying, that he left the ignition key in the mailbox but not the key to unlock the truck door. If that's the case...it makes more sense, and it actually makes it easier to figure out what the heck WH is trying to tell us regarding the truck. He had to leave the vehicle unlocked, because hey, he didn't leave the door key and AJ had to be able to open the door in order to get in and start the truck. But then, why would this be an important detail to share? Maybe because LE has the truck? Maybe in case something odd was discovered, and that base needed to be covered?
(Hypothetical) "I didn't have the key to start the truck, but I did have the key to the door, and that's how I was able to get inside and look around after she went missing?"....that sort of thing, maybe?
Just rolling around in the speculation muck.
ETA: But then, that would mean that AJ would have to leave the truck unlocked in a parking lot if, say, she went to the mall to buy a GoPro or something. Would the owner of a vehicle lend out their vehicle knowing that the borrower would have to leave the truck unlocked? Especially when the door key was available, and could have easily been given to the borrower along with the ignition key?