A federal judge in California has restricted Department of Homeland Security field operations aimed at finding noncitizens suspected of voting, ruling that the government’s methods likely violate federal protections against voter intimidation. U.S. District Judge Araceli Martínez-Olguín’s order, issued late Wednesday, bars DHS officers in California, Connecticut, Georgia, Missouri, Nevada, New York, Pennsylvania, Washington and Wisconsin from conducting operations targeting people they know or reasonably should suspect are U.S. citizens. It also prohibits investigations based entirely on data matching by U.S. Citizenship and Immigration Services without additional inquiry. The order is scheduled to take effect Friday and remain in force through election night; the government may appeal. Homeland Security Investigations officers have recently visited homes to question people suspected of voting unlawfully as noncitizens. The targets may include people who later became naturalized citizens but voted before completing the naturalization process. The judge found that unreliable or incomplete data, combined with highly publicized arrests, could create a reasonable fear of law-enforcement contact and deter citizens from helping others exercise their voting rights. A USCIS official told the court that staff manually review records before referring cases to investigators, but acknowledged that citizens could still be mistakenly identified as potential noncitizens. DHS says its effort is focused on identifying and prosecuting noncitizens who vote, and says it does not plan to question or investigate people it believes are citizens. The case was brought by a coalition that includes San Francisco and Santa Clara counties, the city of San Francisco, nursing unions and Voto Latino Foundation. The ruling comes amid broader disputes over voter-roll checks: the Justice Department is seeking to have California segregate 20,000 ballots tied to people it considers likely noncitizens, while a preliminary review of a sample found registrations that were canceled or inactive, had no voting history, or belonged to people who said they were born in the United States. State reviews and audits have consistently found noncitizen voting to be extremely rare.