Federal prosecutors in Maryland are expected to ask a grand jury Thursday to indict former Trump national security adviser John Bolton for his alleged mishandling of classified documents, sources tell ABC News.

The move comes on the heels of the indictments of former FBI Director James Comey and New York Attorney General Letitia James as President Donald Trump continues what critics call a campaign of retribution against his perceived political foes.

Bolton has been a target of Trump’s ire since leaving Trump’s first administration and publishing a tell-all book. Federal agents in August searched Bolton’s Maryland residence and Washington, D.C., office, related to allegations that Bolton possessed classified information. 

Bolton has denied ever unlawfully removing classified materials from his time in government and has said no such information was published in his 2019 memoir “The Room Where It Happened.” 

The investigation is being run out of the U.S. attorney’s office in Maryland, unlike the Comey and James probes which are being conducted by the Trump-appointed U.S. attorney in the Eastern District of Virginia, who sources say brought the Comey and James charges against the advice of career prosecutors.

Comey, who was indicted on charges of lying to Congress, and James, who is charged with mortgage fraud, have both denied wrongdoing.

Last month, a federal judge unsealed a redacted version of the affidavit that had been assembled by prosecutors in order to execute their court-authorized search of Bolton’s home. Most of the document concerned allegations surrounding the publication of Bolton’s book, which the first Trump administration unsuccessfully sued to block.

The federal judge overseeing that lawsuit expressed grave concerns over whether Bolton had included highly classified information in his book that could potentially compromise national security.

On the day that Bolton’s home and office were searched, Trump said that he was “unaware” of the searches but went on to call Bolton a “sleazebag.” Referencing the FBI’s 2022 search of his Mar-a-Lago home in his own classified documents case, Trump told reporters that having your home searched is “not a good feeling.”

Trump pleaded not guilty in June 2023 to 40 criminal counts related to his handling of classified materials after leaving the White House in 2021, after prosecutors said he repeatedly refused to return hundreds of documents containing classified information and took steps to thwart the government’s efforts to get the documents back.

After Trump was reelected president last November, the case was dropped due to a long-standing Justice Department policy barring the prosecution of a sitting president.

Trump, asked about Bolton in a June 2022 Oval Office interview with Fox News, said, “He took classified information and he published it, during a presidency. It’s one thing to write a book after. During. And I believe that he’s a criminal, and I believe, frankly, he should go to jail for that, and that probably, possibly will happen. That’s what should happen.”

ABC News’ Pierre Thomas contributed to this report.