California Attorney General Rob Bonta, leading a multistate coalition of attorneys general, filed an amicus brief supporting litigation that challenges Immigration and Customs Enforcement (ICE) practices of making warrantless civil immigration arrests without probable cause.
The coalition argues that Congress has established clear limits on immigration agents' authority to detain people, requiring probable cause to show both that the person is removable from the United States and that they pose a flight risk. The brief, filed with the U.S. Court of Appeals for the Tenth Circuit, supports litigation in Colorado on the issue.
"The Trump Administration has sought to instill fear in immigrant communities through indiscriminate, sweeping, and often baseless immigration arrests. This violates the law — and basic human decency," said Bonta. "In California, we've seen firsthand the devastation wrought by the Trump Administration's destructive mass deportation agenda."
The brief cites impacts on state communities including declines in school attendance, farm operations, public health, economic security and public trust between communities and law enforcement. In January 2025, U.S. Border Patrol's "Operation Return to Sender" in Kern County resulted in 78 arrests for allegedly lacking lawful immigration status. The operation included arbitrary roving patrols and warrantless arrests in predominantly Latino areas. A second operation called "Operation at Large" in Los Angeles in June 2025 similarly involved suspicionless stops and warrantless arrests.
Following those operations, communities experienced business closures and cancellations of community events, according to the brief.