I think it will eventually come out that living as a teenager with little parenting or socialization, no goals or activities such as school or work or hobbies or friends, and all day to engage in psycho fantasies with nothing grounding him, he developed an obsession with kidnapping a young girl. I think it'll come out that he purposely started looking some distance away to reduce the chances of being caught which led him to Barron, a place he had spent some time and was at least somewhat familiar with. I think he saw Jayme somewhere, I can't guess where, maybe getting on or off the bus, or at a dance recital, or at cross country practice, and focused on her. Why her instead of any other 13 year old, only he knows. I think he studied the house for some period of time and established that there were two other adults there and apparently no surveillance. Then, I think he made his move, knowing that to kidnap her, he would have to kill both of her parents. That would be the quickest way. I don't think there is any other connection. Sadly, he was very lucky in several respects, to be able to pull it off as he did, and for so long. Without Jayme's bravery, I think it would have gone on indefinitely.