The Trump administration is escalating its fight with California ahead of next month’s midterm election, warning that local officials who process and tabulate ballots submitted by suspected noncitizen voters are putting themselves at risk of criminal investigation and potential prosecution.

The letter Friday from a senior Justice Department official and obtained first by The Associated Press is the latest salvo in an ongoing tussle with heavily Democratic California, coming just a day after the Trump administration sued the state to prevent it from counting mail ballots from people the federal government has identified as “likely” noncitizens until their immigration status can be confirmed.

“The legal consequences for either facilitating or ignoring a federal crime are significant. Noncitizen voting in a federal election is a federal crime — and knowingly facilitating such conduct is equally unlawful,” warns the letter from Trent McCotter, the acting deputy attorney general at the Justice Department.

It adds: “If persons knowingly tabulate ballots cast by individuals identified by federal agencies as noncitizens, they risk becoming aiders and abettors to a federal crime.”

The letter is addressed to the Los Angeles County Counsel’s office and also is copied to California Secretary of State Shirley Weber and Los Angeles County Registrar Dean Logan, effectively putting the entire state on notice.

In response to the letter, Logan said his office is focused on conducting a fair and secure election while noting that Election Day is a mere 18 days away.

“The U.S. Department of Justice has chosen to litigate their unverified assertions of voting eligibility. At this point, it is best for this to be addressed in court,” he said.

The other offices and the state attorney general did not immediately respond to requests for comment.

It is unclear how many individuals the Justice Department might look to try to investigate and charge, though any federal criminal cases in the Los Angeles area would be handled by the office of Bill Essayli, the region’s top federal prosecutor and one of the Justice Department officials who filed the federal complaint Thursday against California.

Trump weighed in late Friday, sharing on Truth Social a link to a news story about the letter and adding: “They will all go to jail for a long period of time!!!”

The Trump administration has made the pursuit of noncitizen voters a priority

Sent less than three weeks before the Nov. 3 election, the letter adds to simmering tensions over voter rolls between California and the Justice Department and reflects the Trump administration’s aggressive hunt for noncitizen voters. It has made the issue a priority this year, including by demanding detailed voter information — including dates of birth, addresses, driver’s license numbers and partial Social Security numbers — from the states.

The Justice Department has charged about 90 people for various types of election misconduct so far this year, including 50 who are alleged to have voted as noncitizens. There were more than 227 million registered voters in the United States during the 2024 presidential election.

In July, Homeland Security Secretary Markwayne Mullin sent letters to California, Nevada, New Jersey and Pennsylvania, alleging that as many as 250,000 noncitizens were registered in those states. Election officials there were skeptical of the claim, including Weber, the California secretary of state.

That same month, the Republican administration claimed Nevada had 1,500 noncitizen voters on its voter rolls. But after the federal government identified them to the state, the number of actual registered noncitizens turned out to be zero.

That experience is backed up by research and investigations in various states, which make clear that voting by noncitizens is extremely rare.