'They’re closing in': Experts explain how DOJ may 'force' Trump aide to testify after he pleads the Fifth

Federal prosecutors investigating the trove of national security documents seized from former President Donald Trump's Mar-a-Lago residence are ramping up pressure on reluctant witnesses in the case, according to The New York Times.

Prosecutors have expressed skepticism about the initial account provided by Walt Nauta, a "little-known figure who worked at the White House as a military valet and cook" before getting hired at Mar-a-Lago, according to the report. Prosecutors are using the "specter of charges" for misleading investigators to pressure him to sit for questioning, the Times reported. Nauta, who was once tasked with bringing Trump Diet Cokes in the Oval Office, initially denied any role in moving boxes of sensitive documents at Mar-a-Lago but told investigators that Trump instructed him to move the boxes in a second interview, according to The Washington Post. Investigators also reviewed surveillance footage showing the boxes being moved.

Prosecutors are also trying to force longtime Trump aide Kash Patel to answer questions before a grand jury after he repeatedly invoked his Fifth Amendment right against self-incrimination in his first appearance.

Patel was named by Trump as one of his representatives to the National Archives and Records Administration to handle his presidential records. Patel was particularly interested in records related to the Justice Department probe into Trump's 2016 campaign ties to Russia, which he publicly said he planned to release.

Patel has also claimed he was in the room when Trump ostensibly declassified the documents before leaving office, a claim that has been refuted by multiple administration officials. Trump's lawyers have provided no evidence in court that the documents were declassified and Patel invoked the Fifth rather than repeating the claim before the grand jury.

Prosecutors have asked a federal judge in D.C. to force Patel to testify. Patel's lawyers have opposed the move over concerns that the DOJ wants to use Patel's statements to incriminate him, according to the report.

The witness testimony is key to the DOJ's effort to prove intent in the case. Prosecutors believe that Nauta could provide inside into Trump's "intentions," according to the report. If Trump had the boxes moved to hide them from the DOJ, it would help prosecutors build an obstruction case.

Nauta, who grew close to Trump while working as a valet, was seen on surveillance footage moving boxes out of a storage area at Mar-a-Lago after Trump received a subpoena for the remaining documents he took home from the White House. Though Nauta initially denied moving the boxes, one source told the Times that he later was "clear with investigators that Mr. Trump had directed him" to move the boxes but another source told the outlet that he was "less specific about who had told him to do so."

Patel, a former aide to ex-Rep. Devin Nunes, R-Calif., who helped lead the House GOP effort to undermine the Russia probe, is a fierce Trump loyalist whom the former president tried to install as deputy director of the CIA in his final weeks in office before the effort was blocked by White House officials. Former Attorney General Bill Barr in his recent book recalled that Trump also tried to name Patel the deputy director of the FBI, which Barr warned the White House would only happen "over my dead body."

Legal experts said the DOJ's pressure campaign could be trouble for Trump.

Prosecutors are likely to give Patel an "immunity deal that he can't in some ways refuse" that would allow him to avoid "criminal liability" in the matter, predicted Ryan Goodman, co-director of the Reiss Center on Law and Security at the New York University School of Law.

"They say you have immunity so you don't risk criminal liability for yourself. 'Now tell us what you know.' And if that's what they're trying to do, that's a pretty strong tactic at this stage," Goodman told CNN, adding that it "looks like they're closing in directly on Donald Trump."

Harvard Law Professor Laurence Tribe tweeted that once the DOJ grants Patel immunity, "his 5th Amendment rights against compelled self-incrimination will evaporate."

"He will then be forced to tell the truth about Trump's role in the Mar-a-Lago crimes against America's national security," he wrote. "The jig will be up."

The move also suggests that Patel is not the target of the DOJ investigation, wrote Renato Mariotti, a former federal prosecutor.

"All of this suggests that DOJ is pressing forward with a criminal investigation and that Trump is their target," he tweeted. "That's significant news that suggests that they won't be satisfied by a deal in which Trump gives them any remaining documents."