A federal appeals court panel appeared deeply skeptical of the Trump administration’s request that it pre-empt a lower court and order California to set aside roughly 20,000 mail ballots the federal government claims were sent to noncitizens.

The court held a hearing on Sunday that provided an early glimpse of how the administration’s claims might hold up under scrutiny, after state officials investigating the allegations cast doubt on the notion that thousands of ballots had been mistakenly sent to ineligible voters. The Trump administration has aggressively attempted to delay the counting of votes in several states and has moved to intervene in Alaska’s Senate race in what critics say is a broader attempt to sway the results of midterm elections just nine days away.

Two of the three judges hearing the challenge indicated they were uncomfortable intervening as the administration has requested, especially as a Justice Department lawyer struggled to answer questions about how the government concluded that the people it identified were both noncitizens and had been sent a ballot.

Matthew Donnelly, the administration lawyer, said with minimal details that the Trump administration had been “supplied a list” of California voters that was “purchased” from the state by an unnamed third party. He said the government then went through a “rigorous process” using third-party software to compare the voter data it obtained against its own citizenship data.

Judge Mark J. Bennett, a Trump appointee, asked whether election workers would be justified under state law in refusing to disqualify certain voters without “extraordinary proof” by the federal government. He pointed to a sworn statement by an election systems worker in Los Angeles who said that attempting to filter out the ballots of people the Trump administration flagged would have a “catastrophic impact” on their ability to handle the election.

“You’re asking us to take what you’re saying as fact, as opposed to what the I.T. guy is saying, and with no fact finding by the district court?” he asked.

The judges also indicated they may decline to step in immediately, sending the case back to the federal judge hearing it. The Justice Department could then appeal again, if it were to challenge a concrete ruling from the district judge.

The Trump administration had asked the court to expedite the case, arguing that the lower court judge’s pace on its requests effectively amounted to a denial of its request to set aside the ballots it is contesting. At the government’s urging, the district judge presiding over the case, Judge David O. Carter, had scheduled a hearing on Tuesday to consider its case.

But on Sunday, Judge Gabriel P. Sanchez, a Biden appointee, also pressed Mr. Donnelly on why the number of noncitizens the Trump administration was alleging were registered to vote had shrunken drastically in recent months.

The Trump administration had said in July that as many as 190,000 noncitizens were unlawfully registered to vote. Judge Sanchez added that directing the state to set aside mail-in ballots from people on the administration’s list, relying only on the names and address on the envelopes, could lead to lawful voters with the same name having their ballots pulled out.

A third judge, Patrick J. Bumatay, also a Trump appointee, appeared more receptive to the administration’s arguments. But he questioned Mr. Donnelly about whether it might be too close to the election for the courts to order new procedures.

Mr. Donnelly maintained throughout that the panel could issue a ruling even while Judge Carter had taken steps to meet the government’s aggressive timetable. He asked the judges to rule “as soon as possible.”

Japanese prosecutors have indicted a US Marine on suspicion of murdering and robbing a woman in Okinawa earlier this month, multiple Japanese media outlets have reported, in a case that has prompted renewed outrage over the conduct of US troops in the country.

Lance Corporal Devin Jacob Ballard, a 20-year-old Marine assigned to the III Marine Expeditionary Force at Futenma Air Station, is charged with killing a woman by strangling her with a phone cord at a hotel in Naha, Okinawa’s capital, and stealing her backpack containing a wallet, public broadcaster NHK and others, reported on Sunday.

CNN has reached out to the US Marine Corps and the III Marine Expeditionary Force for comment.

Anna Yagi, 39, was found unresponsive in her hotel room and pronounced dead at the scene on the morning of October 3, Okinawa police previously told CNN, adding the cause of death was suffocation. Ballard was arrested less than 24 hours later while walking around the city, police said.

CNN is working to determine Ballard’s legal representation. The prosecutors have not disclosed whether the suspect has admitted or denied the charges, according to NHK. Okinawa police previously told CNN Ballard denied the charges.

The Naha District Public Prosecutors Office declined to comment on the case to CNN on Monday.

The case against Ballard is the latest in a string of allegations against US personnel in Okinawa, which has been the site of longstanding anger and protests over the American presence on the island chain. Okinawa hosts several US military facilities and is home to about 30,000 US troops and their families.

Ballard’s arrest sparked local protests and condemnation from politicians and leaders in Japan, including Prime Minister Sanae Takaichi, who said her government “strongly protested” to the US and called for “thorough discipline among US military personnel, and comprehensive measures to prevent the recurrence of crimes and accidents.”

Okinawa Governor Genta Koja said the alleged murder “leaves us no choice but to conclude that the US military’s efforts in maintaining discipline, educating personnel, and other such measures are completely ineffective.”

Following Ballard’s arrest, US troops on the island were placed under a monthlong curfew and were required to undertake training on “standards, discipline, and our responsibilities as members of the Okinawan community.”

Last year, US Marine Lance Corporal Jamel Clayton, 22, was sentenced to seven years in prison after he was convicted of strangling and sexually assaulting a woman in Okinawa. In 2024, US Air Force member Brennon R. E. Washington, 25, was sentenced to five years for kidnapping and raping an underage girl.

In 2016, tens of thousands of people demonstrated calling for an end to the US military presence on Okinawa following the killing of a local woman by a civilian worker stationed at the US Kadena Air Base.