as far as motive the only motive that holds water for me is: Jayme
She's the why
Every other scenario comes up against the brick wall of: 'why take Jayme?'
(only scenario wherein I see that is an unplanned rage attack & Jayme just wasn't on their radar so to speak: didn't have the heart to shoot her, but she could identify them: in a panic they take her: possible, but unlikely)
Especially after the articles about the Australian guy flying to the US to kidnap a 14 year old he met online plus the Colorado guy who was set to go to...Wisconsin... to get this 16 year old that he'd first 'met' online when she was 14...really reinforces my theory of a slightly older male obsessed with Jayme
I think it quite possible whether online or in person: Jayme, whether she was aware of it or not: attracted the attention of some male 18-20 (maybe a little older).....
I think this male is clearly mentally unbalanced, has anger & impulse control issues, socially awkward or even outcast, does not receive any attention from females his own age and then viola!
Here is this nice, sweet gal, sure too young for him, but...he can wait or they'll figure something out...she actually acts like she likes him, she laughs at his jokes, etc etc
Maybe he wants her to sneak out with him, she refuses: says she'll get in trouble: so our young perp decides he needs to kill her parents
OR
Parents know of budding situation & tell him he's too old for their daughter, it's inappropriate & to never contact her again: once more: solution: kill the parents...
I'm still going with this idea....maybe because it gives Jayme her best chance at being alive, and escaping.....
(It's possible the perp was an older man: but the scene seems so violent.....plus I think an older man would have come up with a scenario to take Jayme that didn't include killing the parents (however the Hannah Andersen case contradicts this....plus the Short family too)......)
This is still where I'm at....though that bit @ Sheriff interview of the caller saying a couple is missing since 10/15 & drives a Challenger is pretty interesting....Imagine LE would, heck might be right now, all over that.....fingers crossed!