On 14 October, a federal appeals court ruled against California in its dispute with the Trump administration over identification requirements for federal immigration officers. A Ninth Circuit panel instructed a district court to halt application of the state's No Vigilantes Act as it applied to federal agents.

Under the statute, plainclothes officers carrying out enforcement actions were required to show identification, though certain exemptions applied. The ruling determined that California had exceeded its authority by moving to regulate federal activities without authorisation from Congress.

The ruling limits the authority that state officials hold over federal agents, while leaving untouched the separate and unresolved question of whether immigration enforcement itself operates within legal boundaries. A federal lawsuit filed by the Justice Department against California, Governor Gavin Newsom, and Attorney General Rob Bonta in November 2025 formed the basis for the ruling.

The Supremacy Clause of the US Constitution, which bars states from imposing rules that govern federal government functions, formed the legal foundation of the challenge brought by federal officials against the identification requirement. Passed under the name No Vigilantes Act and taking effect in September 2025, the law required plainclothes law enforcement personnel to carry visible credentials identifying their agency along with either a name or a badge number.

Under that rule, federal agents working within California's borders — ICE personnel among them — were bound by its provisions. Any officer who intentionally violated the provision with full knowledge of doing so faced exposure to criminal prosecution under the relevant state statutes. Exemptions of a limited scope were written into the measure, and agencies retained a path to compliance by publicly posting identification policies that met the defined standards.

The Ninth Circuit ruling dated 14 October found that Section 10 placed direct restrictions on federal law enforcement operations without authorisation from Congress. The court's written opinion stated that the provision overrides the federal government's authority to decide whether, how, and when its officers are identified publicly.

The state contended that its requirement posed no meaningful obstruction to the functioning of federal agencies. Dismissing that argument, the three-judge panel held that any direct regulation of federal government operations by a state rendered the degree of interference beside the point. The panel indicated that the administration's constitutional argument appeared likely to prevail.

The appellate panel set aside the lower court's denial of interim relief, directing that tribunal to put in place an injunction barring California from applying the contested requirement to federal officers. The decision advances the government's position in the litigation, even as it leaves the broader dispute unresolved — covering only an interim injunction rather than a final determination on the remaining claims.

State authorities in California took issue with the decision, contending that officers conducting immigration enforcement operations were required to display visible identification in the interest of public safety and accountability. A statement from Bonta's office conveyed that the ruling left the team there dissatisfied and that attorneys were examining the opinion in detail. The written submission put forward a position that officers who do not disclose their identities risk eroding the public's trust in policing.

Prior to this dispute, Bonta had put forward the measure as a protection against anonymous actors working within California neighbourhoods. Transparency and accountability in policing were described by his office as foundational to how it functions effectively. Newsom's office put forward objections to the immigration enforcement methods used by the Trump administration, contending that those approaches have placed strain on households and local communities.

The appeals court ruling drew a positive response from federal officials. Two officials from the Justice Department offered their assessments — Brett Shumate, serving as Assistant Attorney General, called it a positive outcome, while Stanley Woodward, in his role as Associate Attorney General, characterised it as a gain for those who enforce federal law. The administration's position, as conveyed through those statements, held that congressional authorisation governed how federal officers performed their duties — not directives from California.

The Ninth Circuit ruling built on a series of prior court orders that had already blocked California from applying the identification requirement to federal officers. At the district court level, that provision had faced no immediate injunction. On 19 February 2026, a temporary administrative injunction from the appeals court put enforcement on hold for the duration of the proceedings. A temporary injunction pending appeal was put in place by the court on 22 April. The appellate decision from October overturned the lower court's refusal to grant preliminary relief, ordering that court to put a preliminary injunction in place.

Part of the same legal action also took aim at a separate California statute — the No Secret Police Act — which placed limits on when law enforcement personnel could wear masks or other face coverings while on duty. That restriction had been put on hold by a district judge, who ruled it could not be applied to federal officers. Provisions addressing masks fell outside the scope of the October appeal, which had been limited solely to the identification requirement under the No Vigilantes Act.

Identification requirements covering state or local law enforcement personnel fall outside the boundaries of what the ruling addresses. Federal officers retain whatever independent duties arise under federal law, and those remain unaffected.

The legislation passed in California took shape against a backdrop of community unease over enforcement actions targeting immigrants and the deployment of federal agents whose identities were not disclosed. Proponents contended that requiring officers to carry and present identification would give residents a way to verify who they were dealing with and hold enforcement personnel answerable for their conduct.

The ruling leaves intact the administration's authority over how its agents may present their official identities when performing duties in the field. The decision halts the application of the state legislation that sought to bring greater transparency to immigration enforcement operations. No resolution has been reached on the wider disagreement. On a provisional basis, the appeals court struck down the state identification requirement — a decision that does not address the validity of federal enforcement tactics or settle the broader, unresolved questions surrounding how immigration policing operates and is held to account.