Threatened him how? Need more details before advising you to go into his house armed.
Guy sounds like a jerk, but yelling at your nephew is not a reason to go into his house.
If he ever lays a hand on him though, then anything goes
Unacceptable. Do let the police know, it covers your butt later if you do wind up defending your nephew. This is an unprovoked harassment and is terrorism to your nephew. I might also mention it to a lawyer. then let the guy know face to face how you feel.
Then kill his lawn. No, the last one was just a joke. Maybe. Yeah a gallon of round up over night. Just kidding. Maybe.
Depends, how badly did he threaten the kid?
what do you need a gun for?.. wouldn't it be more pleasurable to rip him a new one with your hands?...
its not the size of the dog in a fight, its the size of the fight in the dog...
Call the police.