or county may vary, but in the US we have some "right to work" states, and also statutes that allow both parties to execute separation without notice. The worker can quite with out notice and not be blacklisted, and the boss can fire without prejudice to the worker. It is called the "open shop rule". This applies to all but union shops, where the state deferrs to the rules the union members vote in.
So even though law enforcement can be a different situation, unionized police would have the same protections.
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