I've long thought whoever was responsible (and I think foul play was definitely involved), was someone either Jason knew in some capacity or lived nearby. I suspect he was being watched during the days his car was in the shop and he was getting to work by other means (which I've not been able to really confirm how he got to work those days, specifically).
The fact nobody claimed to see him walking the probable routes he'd take to get to the high school parking lot (where his coworker was waiting) make me wonder if he was lured into a car or house near his own home. Maybe on the same street he lived on. I think he knew the response person, in some way.
Also, there is the alleged claim that when the Fizolis manager called the house, to ask him to cover a shift, that Jason's younger brother actually had answered the phone and pretended to be Jason until confronted. If true, I found that strange given the eventual circumstances....dies anyone know anything more about this specific tidbit?