The Department of Justice is demanding California segregate ballots for 20,000 people it identifies as "likely" noncitizens. State and local officials responded in court filings Tuesday, calling the federal government's data "unreliable" and saying some individuals on the list indicated they were born in the United States.

The federal government filed a lawsuit to compel California to investigate these thousands of individuals before their votes are counted. The state asserts that fulfilling the DOJ's request is unfeasible given the proximity to the election and would likely violate federal and state election laws.

California's court filing called the litigation "at best, a reckless political stunt. At worst, it threatens to disenfranchise thousands of Californians this election."

The dispute began last week when the Justice Department delivered a thumb drive containing the list of approximately 20,000 people to Los Angeles County. Investigators at the Department of Homeland Security identified these individuals as "likely noncitizens" registered to vote across California.

Los Angeles County officials initially declined to open the thumb drive due to security concerns about unknown origins. The Justice Department emailed a spreadsheet with the same list the following day.

Los Angeles County Registrar Dean Logan stated in a Tuesday court filing that of the 20,000 names, only 7,035 had addresses within Los Angeles County. Logan also noted that some entries were duplicates.

Los Angeles County Assistant Registrar-Recorder Monica Flores submitted a declaration detailing a preliminary review. County staff examined a sample of 200 people from the list to assess the federal data's reliability.

Flores wrote that the review indicated "the October List is unreliable." For voters where birthplace was "meaningfully reported" within the sample, 38.9 percent indicated they were born in the United States.

Flores specified that a U.S. birthplace constitutes "strong evidence of citizenship." Under current U.S. law, individuals born in the country automatically receive citizenship, with only extremely narrow exceptions. The California Secretary of State's website asks for "place of birth" during online voter registration, though this field is not mandatory.