There's a very good chance the cops in question do not work for the Federal government. They certainly don't work for the judicial branch. It isn't a perfect setup, but it's better than many.

The whole thing is intertwined. Podunk cops often get put on 3 letter task forces and work in a mutual arrangement with each other. They often have a really clever scam going on where they kick seizures up to federal agencies, since it is so much harder to block/contest federal forfeitures than local ones, and then the federal agencies kick back a fraction of it.

Maybe their paychecks don't come from the federal government nominally but in practice it's highly intermixed.

They all get paid from my pay check. They work for the government. Level doesn’t matter. They protect their own.