It was the ATF, he superficially shot one, and was shot in the head with his brother saying he's not expected to live. I wonder if this was just over having like an illegal silencer/machine gun or something.
What's pretty fucked about this generally is that if you're making 250k/year, you can afford to buy a legal machine gun. There's only a few of them out there and they cost like 20k minimum, but it's literally something you can do if you have enough money and can just wait for the ATF to process your paperwork.