A federal appeals court has ruled that California cannot require federal immigration agents and other federal officers to display identification while carrying out enforcement operations in the state.
In a decision issued Wednesday, a three-judge panel of the Ninth Circuit Court of Appeals found that Section 10 of California’s “No Vigilantes Act” violates the Supremacy Clause of the U.S. Constitution. The ruling reverses a lower court decision and orders a preliminary injunction blocking the state from enforcing the identification requirement against federal agencies and officers.
The law, passed in 2025, required non-uniformed law enforcement officers operating in California, including federal agents, to visibly display their agency and either a name or badge number while performing enforcement duties. Officers who refused could have faced misdemeanor charges under state law.
Judge Mark Bennett, writing for the panel, said the measure amounts to a state attempt to directly regulate the federal government while it carries out its own functions, something states cannot do without Congress’s authorization. Because law enforcement is a core government activity, the court found the identification mandate invalid in every application to federal officers acting under federal authority.
The panel went further than simply finding the federal government likely to prevail. It stated the government was “certain” to win its constitutional challenge.
California had argued the law was lawful because it did not substantially interfere with federal operations. The judges rejected that argument, ruling that even minimal interference doesn’t matter when a state is directly regulating federal government conduct. The panel included Judge Jacqueline Nguyen, an Obama appointee, along with Trump appointees Bennett and Daniel Collins. The court had already paused enforcement of the requirement in April, ahead of Wednesday’s ruling on the merits.
California lawmakers passed the No Vigilantes Act in 2025 following a wave of federal immigration sweeps across the state, many carried out by masked agents in unmarked vehicles, which drew objections from Democratic officials. Gov. Gavin Newsom signed the measure alongside the No Secret Police Act, which restricts officers from wearing face coverings and was separately blocked by a district judge earlier this year.
With the Ninth Circuit siding with the Trump administration, California’s options narrow to seeking a rehearing before the full appeals court or petitioning the U.S. Supreme Court.
The decision reopens a long-running dispute between California and the federal government over how immigration enforcement is carried out in the state.
