There is a chance that JP's parents never saw anything troubling in their son. They may have thought he was a little "odd" or "different", perhaps secretly thought he might have issues that needed to be addressed with a doctor, but never saw any violent or otherwise troubling tendencies in him. When I was a teenager, I was kind of Queen Bee of the weird kids-we were the ones who stayed in the art room during lunch playing D&D, the ones who'd rather go for drives to take pictures of old houses and cemeteries than party, the ones who would do 48-hour video gaming sessions, etc. Parents kicked me out of slumber parties for scaring the other kids with games like "Light as a Feather" and telling ghost stories that were too scary. We were all kind of socially awkward and, until we met each other, loners, but none of us have ever committed crimes. JP could have done a good job of hiding whatever signs there were-IF there were any signs at all. They may have been concerned about his work history, for instance, but shrugged it off as him just "trying to find his way."
Kinda withholding judgment on the parents until we hear more about JP's background, childhood, etc.
