I have a theory but it is just that, a theory. And bare with me because I may seem like I am saying jayme had a part in it but 100% am NOT saying that.
My theory is that is was somewhat like the dede Blanchard case - expect jayme wasn't being tortured but just complained about normal teenage/ parent struggles. Perhaps she met this man online and vented to him about not having the freedom she wanted to or something, so he decided to take it into his own hands and "free" her from her parents.
Again, I do not think she actually wanted her parents dead and I am NOT saying he thought he was saving her, I think he was obsessed with her and sick.
I am so happy Jayme is safe but my heart breaks for her and the pain she has been going through and will continue to go through. Prayers that she is able to heal.