Justice Dept. Pressures California With Expanded Election Investigation The department has issued grand jury subpoenas to local election officials as part of a widening effort to prove unsubstantiated claims about large numbers of illegal voters in the state.

The Trump administration has widened a criminal investigation in its intensifying campaign to prove thousands of noncitizens are on California’s voter rolls, issuing federal grand jury subpoenas to local election officials, according to people with knowledge of the matter and copies of subpoenas obtained by The New York Times.

The move escalates the Justice Department’s pressure on the most populous state as the administration seeks to tighten its grip on the midterm elections by making unsubstantiated claims that large numbers of illegal voters are on the rolls. A day earlier, a federal judge resoundingly rejected the Trump administration’s bid to block the state from counting the votes of some 20,000 people it says are likely noncitizens, even though studies have found such fraud is very rare.

The new subpoenas are part of the administration’s broader effort to portray elections in Democratic states as rigged against Republicans. Justice Department officials have repeatedly suggested they would investigate and prosecute local election officials who did not accede to federal demands to set aside ballots of people that the administration had claimed were likely noncitizens. The people with knowledge of the matter spoke on the condition of anonymity to discuss sensitive legal matters.

At least two employees of Los Angeles County Registrar-Recorder’s office received grand jury subpoenas last week for a proceeding scheduled for Nov. 4, on the morning after the election, according to records obtained by The Times through the state’s public records law. Federal marshals served one county employee at home, despite having already served that employee at the registrar’s office and issuing a notification of counsel, according to officials familiar with the incident.

Already, the Trump administration has sought records on individuals whom prosecutors appeared to suspect lacked the citizenship status required to cast ballots. The new round of subpoenas appear directed at election officials themselves, seeking copies of all internal communications about the Justice Department’s demands to county officials and the California secretary of state. They also ask for all records involving the agency’s “methods for screening for unlawful voting by aliens” and “efforts to prevent noncitizen votes from being counted in any election.”

Using criminal justice processes like grand jury subpoenas may allow the administration to gain access to records that it has so far failed to acquire through a lawsuit and menacing letters. Such a subpoena does not mean that the person who receives one is under investigation; the Justice Department rarely subpoenas individuals it intends to charge with a crime.

Dean Logan, the Los Angeles County registrar, denounced the subpoenas as “intimidation.”“At every step, the U.S. Department of Justice has taken a confrontational, adversarial approach,” he said in a statement. “Election officials are acting in accordance with state and federal law.”Shirley Weber, the California secretary of state, declined to comment on the subpoenas.

A Justice Department spokeswoman also declined to comment but noted that California officials and a federal judge have recently emphasized that issues of unlawful voting should be addressed through criminal prosecution. The administration has repeatedly signaled that it would escalate its fight with the state.

Last week, Justice Department officials notified local election officials in a letter that they would “risk significant federal scrutiny” if they did not help identify potential noncitizens on their rolls and set aside their ballots. Bill Essayli, the top federal prosecutor in Los Angeles, where the new subpoenas were issued, also suggested that election officials could be prosecuted. “Any election official who knowingly processes the ballot of a noncitizen is opening themselves to legal jeopardy,” he said.

The Trump administration’s lawsuit this month seeking to block the state from counting the votes of some 20,000 people opened a new front in its clash over California’s voter rolls. State officials have said that the federal data that generated a list of names is unreliable and that the demand comes at a time when officials are not supposed to make significant changes to voter rolls or rules.

In his ruling this week, Judge David O. Carter rebuked Mr. Essayli for continuing to claim in court that state and county officials who failed to comply with federal demands could be charged with aiding and abetting criminal offenses. “The court reiterates what it said yesterday; these threats must stop,” the judge wrote. Mr. Essayli has been at the forefront of the Justice Department’s efforts to force California to comply with the administration’s demands.

In June, President Trump ordered Mr. Essayli to open an investigation into the state’s primary election. After a district judge ruled against the Justice Department on Wednesday, Mr. Essayli described the current standoff with the state as an “ongoing emergency” and noted that because California is a vote-by-mail state, ballots are already being processed every day by election officials.

Justice Department lawyers have appealed the judge’s decision, and Mr. Essayli said this week that he anticipated the question would be decided by the Supreme Court. Devlin Barrett covers the Justice Department and the F.B.I. for The Times.

Shawn Hubler is The Times’s Los Angeles bureau chief, reporting on the news, trends and personalities of Southern California.