If an immigration officer kills someone without good reason, he’s a criminal.
If an immigration officer kills someone without good reason, all his colleagues around don’t react, he isn’t immediately arrested, and the president of his country covers for him by lying, it’s not just one criminal ; it’s a large-scale criminal organization.
This is all precedent setting.
Take poorly-trained goons, recruited with blatant white nationalist marketing... give them a gun and all of the legal protections Federal LEO's are anointed with, and let them loose with an explicit mandate to "save civilization".... and this is what you get.
Today, they opened fire because they maybe kinda got bumped by a car moving at 2 mph. Tomorrow it will be "he pushed me." Day after that it will be "she shouted at me and I feared for me life."
Scary but true.
