The U.S. Justice Department has sued the City of Milwaukee to stop officials from enforcing a municipal ban on most face coverings worn by federal law enforcement officers, escalating a dispute over immigration operations, officer safety and the constitutional limits of local authority.

The civil complaint was filed Thursday, July 23, in the U.S. District Court for the Eastern District of Wisconsin. It names Milwaukee, Mayor Cavalier Johnson, City Attorney Evan Goyke and Milwaukee Police Chief Jeffrey Norman as defendants in their official capacities. The government is asking the court to declare the ordinance unconstitutional as applied to federal officers and to issue preliminary and permanent injunctions preventing the city from enforcing it against them.

At issue is Milwaukee Code of Ordinances Section 105-140, known as the city’s Law Enforcement Identification ordinance. The Common Council passed the measure on April 21, and the Justice Department’s complaint says it took effect May 9. The ordinance generally prohibits law enforcement officers from wearing opaque face coverings while interacting with members of the public in the performance of their duties.

It also requires officers acting in an official capacity to display the name or commonly recognized initials of their agency together with a last name, badge number or identification number. As an alternative, an officer must provide that information verbally when asked. A person who willfully or knowingly violates the ordinance can face a municipal forfeiture ranging from $5,000 to $10,000.

The measure is not limited to Immigration and Customs Enforcement or other federal agencies. Its definition of law enforcement includes local and state officers as well as federal employees or agents authorized to carry firearms, make warrantless arrests and enforce federal criminal, customs or immigration laws.

Milwaukee included several exceptions. The face-covering restriction does not apply to transparent shields, medical masks, respirators or equipment needed for protection from disease, smoke, toxins or other hazardous conditions. Masks may also be worn during prolonged outdoor assignments in extreme weather. Undercover officers and tactical team members using protective equipment are exempt from both the masking and identification provisions in specified circumstances.

The Justice Department argues that those qualifications do not cure the central constitutional problem. Its complaint relies on the Supremacy Clause and the related doctrine of intergovernmental immunity, which generally prevents states and municipalities from directly regulating the federal government or discriminating against federal operations.

Federal officials contend that decisions about whether agents wear masks or disclose individual identifiers are operational judgments reserved for federal agencies. The complaint says local penalties could force officers to choose between following federal instructions and risking prosecution under Milwaukee law.

The department also says masks can protect agents and their families from harassment, online identification campaigns and violence. It argues that mandatory disclosure of personal identifiers could compromise sensitive investigations, allow criminal organizations to identify participating officers and discourage personnel from conducting enforcement operations in the city.

“State and local leaders cannot tell federal officers how to do their job,” Associate Attorney General Stanley E. Woodward Jr. said in the department’s announcement. Assistant Attorney General Brett Shumate said the federal government, rather than the city, has authority to determine what equipment its agents may wear.

First Assistant U.S. Attorney Brad Schimel for the Eastern District of Wisconsin said the ordinance could place federal and local officers in conflict when they would otherwise be expected to cooperate. The department described the case as part of a broader initiative challenging state and local policies that it believes obstruct federal law enforcement.

Milwaukee officials have framed the ordinance as a generally applicable public-safety measure rather than an attempt to control immigration policy. The city’s legislative findings say masked officers can cause fear and intimidation, obscure facial expressions during already tense encounters and make it harder for residents to determine whether an armed person is a legitimate officer.

The ordinance also cites the danger of law enforcement impersonation. City officials argue that residents may hesitate to obey legitimate commands—or may submit to an impostor—when armed personnel conceal their faces and do not provide clear identification. Milwaukee says the requirements promote transparency, accountability and safer interactions without preventing officers from performing lawful duties.

The conflict intensified after recent federal immigration operations in the Milwaukee area. Spectrum News reported that approximately 39 people were arrested by ICE in late June. Johnson subsequently said people interacting with law enforcement should be able to identify the officer, badge, name and agency involved.

Before filing the lawsuit, the Justice Department demanded assurances that Milwaukee would not enforce the ordinance against federal officers. Goyke rejected that request in a July 17 letter, calling the law a “vital public safety measure.” He said he would not advise city officials to create a federal exemption and that his office would prosecute valid citations issued under the ordinance.

Goyke argued that the law does not prevent federal agencies from conducting arrests, investigations or other authorized operations. He maintained that federal personnel do not receive blanket immunity from every state or local rule that incidentally affects the manner in which official duties are performed.

The city may also emphasize that Milwaukee’s ordinance is broader than some measures previously challenged in federal court because it applies to officers at all levels of government. That distinction could become important as the court considers whether the law directly regulates federal operations or instead imposes neutral public-safety standards across jurisdictions.

The Justice Department has pursued similar challenges involving mask, identification or operational requirements in California, Connecticut, New Jersey, New York, Virginia and Philadelphia. The department said it has obtained preliminary relief in every case in which a court has ruled on its claims, although preliminary orders do not necessarily determine the final outcome of litigation.

In the Milwaukee case, the federal government has presented one principal constitutional claim rather than alleging that the city violated a specific federal statute. It argues that the local ordinance itself is invalid when applied to federal officers because it attempts to control how they perform federal duties.

No final ruling has been issued, and the filing represents the federal government’s allegations and legal position. Milwaukee will have an opportunity to answer the complaint and oppose any request for an immediate injunction. Until a court intervenes or city officials change course, the ordinance remains the subject of an unresolved enforcement dispute between Milwaukee and the federal government.

The case could provide another test of how far local governments may go in responding to public concern about masked immigration agents. It also presents a broader question likely to recur across the country: whether transparency and anti-impersonation rules can be enforced uniformly against law enforcement personnel without intruding on the federal government’s constitutional independence.