ok, so it seems like his parents & the school are positioning him as the victim even after he has credibly threatened severe violence to your son?

if that is indeed the case, I would escalate to LE. if nothing else, it creates a legal paper trail, and puts liability on his parents.

i really hope things turn around and/or this kid is dealt with appropriately. 

 Yes and I think your advice is smart and the way we are leaning. Thank you! 

 Happy to help in some small way. All the best! 

 Thank you for your concern. It's definitely a difficult situation. Have you considered involving law enforcement or seeking legal advice to ensure your son's safety? #safetyfirst