Sorry if I end up repeating things here. I've tried to read every post, but I have to admit I skipped over some during arguments/debates, and a few other things. Seems like every time I almost catch up, my computer freezes up until I'm a few pages behind again. I read several things I wanted to comment on, but wanted to make sure I wasn't repeating anything first. I hope I can remember them.
I believe it was tlcox who commented on him possibly getting spooked and leaving before he had the body where he wanted it. I was thinking about that earlier too. I thought he may have stopped to put it into the shack, but saw headlights and just dropped her and took off. It is possible that he had planned to throw out the backpack there too, but didn't have time once he got back to his vehicle.
A few people mentioned the possibility of him leaving a body part in the backpack, but I believe the man who found it did look through it. He had mentioned that there was a key chain inside with her name on it in addition to the water bottle.
As far as profiling being behind the times, I only agree to some extent. There have been some changes over the past 20 years, but I don't think it's as much as people think. A person with a low self-esteem is probably likely to respond to things in much the same way today as one did 20+ years ago. A person living alone today would still have many of the same advantages/disadvantages that one had back then. I think the basics of profiles are still valid using most of the criteria that has been used. I do think there is more violent crime committed by young people, but most of it seems to be more reckless, impulsive, disorganized, and/or gang related from what I've been seeing.
I agree that he may have wanted her "remains" found, but I'm not sure he wanted her body found. I'm still not convinced that that wasn't just a miscalculation on his part. I don't believe the damage to her body was to prevent identification, but I go back and forth a lot on what the reason might be. One I don't remember writing about already is to hide evidence that might point to him - such as shooting her with a gun that uses rare ammunition, ligature marks on her wrists from something easily identified (such as handcuffs or dog chains, but could be any number of things), an unusual blade, or he may have left teeth marks in some areas, etc.
I don't know what the name of it was, but I think the Criminal Minds episode mentioned was the one where the guy strangled a girl, and had just gotten out of prison for it. His mother was murdered, and he was set up to be blamed. In that one, he would take his girlfriend to all of the dump sites to have sex, and he had pictures of the various spots. MOO
I thought the times nursebeeme mentioned were interesting, and it made a lot of sense to put the backpack there to draw attention away from the dump site. I was wondering if she may have actually been left alive there for a while, and he wanted to get her out if there (or get rid of her) before the area was searched.
I also thought A_rod_777's idea was interesting, but I'm not sure how I feel about it. Was she actually close to the airport when she was taken? I thought it was more in the area SE of there (where it says Westminster). It is possible that he tried to make it look like some kind of satanic ritual, but I really don't see it. I also had thought he may have put the backpack where it was to put suspicion on someone in that area, but it's hard to say.
Sorry for writing another novel, but I wanted to try getting something posted before midnight for a change.