California Attorney General Rob Bonta co-led a multistate coalition in filing an amicus brief in the U.S. Court of Appeals for the D.C. Circuit in support of litigation challenging the Department of Homeland Security's policy and practice of conducting warrantless civil immigration arrests, his office announced on October 19, 2026.

The brief was filed in Escobar-Molina v. DHS, a case challenging DHS's policy and practice of conducting warrantless civil immigration arrests in the District of Columbia. On December 2, 2025, the U.S. District Court for the District of Columbia granted in part a motion for a preliminary injunction in the case, according to the California attorney general's office.

Under federal law, the brief argues, immigration officers conducting warrantless civil immigration arrests must have probable cause to believe that an individual is unlawfully present in the United States and is likely to escape before a warrant can be obtained. The states argue that DHS officers routinely carry out warrantless arrests without determining whether the individual is an escape risk.

"The Trump Administration has engaged in an aggressive, militaristic mass deportation program with no regard for people's humanity and dignity," Bonta said in the statement. "Federal immigration agents are arresting people without the requisite probable cause determination, often while masked, wearing armor, and carrying lethal weapons. California will not stand by while this Administration creates fear in our immigrant communities. We will continue to fight back, defend our neighbors, and stand up for the rights and dignity of every person." That is the coalition's allegation and argument; the court has not issued a final ruling on the appeal.

Bonta, District of Columbia Attorney General Brian Schwalb and Colorado Attorney General Phil Weiser led the filing, joined by the attorneys general of Arizona, Connecticut, Delaware, Hawaii, Illinois, Maine, Maryland, Massachusetts, Michigan, Minnesota, Nevada, New Jersey, New Mexico, New York, Oregon, Rhode Island, Vermont, Virginia and Washington, the California office said. Connecticut Attorney General William Tong issued a separate statement joining the same brief, saying, in his words, "There is a reason basic due process exists in the United States of America."

The California statement said aggressive enforcement has kept students out of school, disrupted agricultural work and discouraged people from seeking medical care in California — claims the coalition makes in the brief. Separately, the Cato Institute, joined by Fair and Just Prosecution and the Law Enforcement Action Partnership, said it had also filed an amicus brief at the D.C. Circuit defending the injunction, arguing that the Fourth Amendment requires immigration arrests to be based on probable cause. Sources: California Attorney General's office (press release, October 19, 2026); Connecticut Attorney General Tong's office; Golden Coast Journal; Cato Institute.