The Justice Department has given California just 48 hours to prove that a list of roughly 20,000 people it suspects are noncitizens illegally registered to vote doesn't include actual U.S. citizens — even as federal agents are already making arrests off the list, and a Los Angeles County review has found a sizable chunk of the names belong to people who say they were born in this country.

The ultimatum arrived in a letter to California Secretary of State Shirley Weber from Trent McCotter, the acting deputy U.S. attorney general, along with a password-protected thumb drive containing the names. "If you cannot implement this process by then, given the ongoing federal election, the United States will have no choice but to seek emergency relief," the letter warns, referring to next month's Nov. 3 elections.

Los Angeles County Registrar Dean Logan confirmed his office received the letter and the drive, but said the office still doesn't have a clear count of exactly how many names on it are tied to L.A. County voters specifically. California officials have already called the broader list "outrageous," and the state has so far declined to act on it — a refusal federal officials cite as the reason they moved to direct enforcement instead.

Armed agents, and a citizenship problem

Federal law enforcement has used the list to justify more than two dozen arrests so far, according to local station KABC, with officials describing the detentions as tied to allegations that noncitizens registered to vote, and in some cases cast ballots. DHS agents have been going door to door asking residents directly about their immigration and voter-registration status, according to CBS News.

A "HIGH PERCENTAGE" OF THE NAMES ON THE LIST WERE BORN IN THE U.S., ACCORDING TO THE COUNTY'S OWN REVIEW.

That's where the list's credibility problem comes in. A Los Angeles County review cited by ABC News found that a "high percentage" of a 200-person sample pulled from the DOJ's list were, in fact, born in the United States — meaning agents may be knocking on the doors of actual citizens based on a roster the Justice Department itself has acknowledged is unverified. Democracy Docket reported the list's origins trace to a broader federal push that has already produced similar disputes in other states.

The arrests have drawn sharp pushback from local officials. California's position, echoed by several county registrars, is that the DOJ's methodology for flagging "suspected noncitizens" is unreliable — built from data-matching techniques that have a track record of flagging naturalized citizens, people with common names, or voters whose records simply contain clerical errors.

What's next

The 48-hour deadline set in McCotter's letter puts California in a bind just weeks before Election Day: comply with a federal demand built on a list the county's own spot-check suggests is substantially flawed, or risk the emergency legal action the DOJ has threatened. Registrar Logan's office said it is working to cross-reference the names against county voter files, but has not committed to a timeline beyond the window the DOJ set. Civil rights groups have signaled they're preparing to challenge any further enforcement action tied to the list, and county officials in at least one other California jurisdiction are conducting their own parallel reviews.