Can the FBI overrule county sheriffs?

The FBI can operate in a jurisdiction and carry out federal investigations, but it does not have the authority to overrule county sheriffs in their law enforcement duties. Each operates under its own jurisdiction; sheriffs manage local law enforcement, while the FBI handles federal matters. However, if a situation involves federal law or national security, the FBI may take precedence, and sheriffs may be required to cooperate with federal agents. In practice, collaboration between the two can vary based on the circumstances.