Judge Blocks Warrantless Immigration Arrests Across Southern California

A federal judge has barred immigration officers from carrying out warrantless civil arrests across Southern California unless they first determine that the person is likely to flee.

U.S. District Judge Maame Ewusi-Mensah Frimpong granted a preliminary injunction on Sept. 2 that was unsealed Wednesday. The order covers the Central District of California, a region that takes in Los Angeles, Orange, Riverside, San Bernardino, Ventura, Santa Barbara and San Luis Obispo counties.

Under the ruling, officers must weigh the "totality of the circumstances known to the agent or officer" when judging whether someone is likely to escape before making an arrest without a warrant. Frimpong also directed the government to thoroughly document the probable cause behind an arrest before a warrant can be obtained.

The judge rejected the idea that unlawful presence alone justifies a warrantless arrest. "Without this, Defendants cannot show that any arrest was proper," she wrote. She also turned down a government request to stay or delay the order while an appeal is pursued.

The lawsuit was filed last fall by the American Civil Liberties Union of Southern California, Public Counsel and immigrant advocacy groups in Los Angeles, amid a sharp rise in immigration enforcement in the region. The case also sought to curb roving patrols that stop and arrest people based solely on race, language or occupation, and to protect access to counsel for those in detention.

Frimpong had earlier issued a temporary restraining order limiting sweeping immigration operations, but the U.S. Supreme Court lifted it last September. Justice Brett Kavanaugh said apparent ethnicity could be a relevant factor in a stop when combined with other information.

The preliminary injunction followed an Aug. 13 hearing at which the judge signalled in a tentative ruling that she was inclined to side with the plaintiffs. Federal judges in Portland, Colorado, Washington, D.C., and the Eastern District of California have already blocked similar warrantless arrest practices.

Plaintiffs argued in court documents that in many arrests tracked in Southern California, no documentation was produced showing that arresting officers had assessed the likelihood of escape. A federal attorney, Daniel Mummolo, said there is no statutory requirement to document such assessments and that different officers handle the process differently. He pointed to a January 2026 memo from former acting ICE director Todd Lyons stating that officers could make an "on-the-spot" determination about escape risk.

Frimpong responded that the government had not presented evidence of officers saying they had made the assessment without writing it down. Plaintiffs' attorney Laura Perry Stone said the memo requires officers to determine both that a person was likely to leave the location and that they were unlikely to be found at another identifiable place, such as a home or workplace.

In her order, Frimpong said a "wealth of record evidence" — including government directives, arrest narratives, agent depositions and video — showed the government's policy and practice was to base escape-risk assessments solely on unlawful status or "false assertions," or to skip the assessment altogether. She cited one case in which the government claimed a person was "running away" from agents before being questioned, while video showed him walking at a normal pace and texting on his phone before the agent approached.

Mayra Joachin, an attorney with the ACLU of Southern California, said the order should end hundreds of unlawful arrests across the region and that the group would monitor compliance closely. The U.S. Department of Homeland Security did not immediately respond to a request for comment.