I have held the belief that Sierra was murdered from the get-go. That was before I researched sex trafficking in CA. I had no clue that this was going on and to the degree that it is. If she was taken for that purpose, the type and location of DNA discovered in the car, bag, etc., makes perfect sense. This would also explain why the body hasn't been located. It would also explain the oddness of his previous failed kidnapping attempts - You use a tazer or stun gun if you want to ensure that your victim remains alive. Just thinking out loud here.