Worried my 15-year-old son might be selling drugs.

In the past year or so my son (high school freshman) seems to come home from school regularly with expensive sneakers and clothing, and always seems to have cash on hand. His stories about how he acquired the shoes and clothes are always very flimsy. His behavior is increasingly sketchy. Yesterday he went for a jog. He never runs. He left and about five minutes later and comes sprinting up the street and he tells me ran a mile and a half and all about his route. No way he ran that far that fast, wasn't out of breath or sweating, and randomly had one of those Nike string backpacks with him that I have never seen before. It's my assumption that he met someone up the street for some reason and came right back home. Worth noting that yesterday was the last day of the holiday break and if he is selling drugs at school he would need to re-up his supply before going back to school.He has two uncles on his mother's side that he is really tight with. They're mid-twenties. Both are complete losers. I am guessing that one of them is supplying my son with either weed or vaping pods and my son is selling them at school. This wouldn't be the first time that side of the family has helped my son lie to me. They are a toxic group of addicts. They are completely unstable and some of the most devious and dishonest people I have ever met. I also wouldn't put this past his mother or her mom, as neither of them works and they are always desperate for money and I know they "borrow" money from my son pretty regularly. It just seems more like something the uncles would do.What's the play here? If I confront him he will deny and deflect. I can't not leave him alone as our school and work schedules allow him about two hours by himself every afternoon so there is a large window that is tough to monitor. I have poked through his room but haven't found anything. I felt like a real scumbag doing that. Has anyone ever been through this as a parent or even when they were his age? I am open to any suggestions. Any suggestions on how to catch him red-handed? via /r/Parenting https://ift.tt/2Qs6pFv