A Georgia prosecutor probing whether Donald Trump and his allies illegally sought to overturn the state’s 2020 election results is expected to seek an indictment from a grand jury next week.

Two witnesses who previously received subpoenas confirmed on Saturday that they have been told to appear before a grand jury in Atlanta on Tuesday, the clearest indication yet that Fulton County District Attorney Fani Willis will lay out her case to the jury after more than two years of investigating.

Geoff Duncan, the state’s former lieutenant governor, told CNN that he had been asked to testify on Tuesday.

“I’ll certainly answer whatever questions are put in front of me,” said Duncan, a Republican who has criticized Trump’s false conspiracy theories about the 2020 election.

An independent journalist, George Chidi, said in a post on X, the site formerly known as Twitter, that he had also been instructed to appear on Tuesday.

A spokesperson for Willis’s office did not immediately respond to a request for comment on Saturday. She has already indicated she would seek charges by the end of next week, and security measures have visibly increased around the county courthouse in recent weeks.

If Trump is charged in Georgia, it would mark his fourth indictment in less than five months, and the second to arise from his efforts to overturn Joe Biden’s 2020 victory. He was charged earlier this month in Washington federal court with orchestrating a multistate conspiracy to reverse the election results.

Special Counsel Jack Smith, who brought the Washington case, has also charged Trump separately in Florida with illegally retaining classified documents after leaving office and with obstruction of justice.

Manhattan prosecutors, meanwhile, indicted Trump this spring for falsifying business records to conceal hush money payments to a porn star who says she had a sexual encounter with Trump years ago.

Trump remains the front-runner for the 2024 Republican presidential nomination, despite his legal woes. He has portrayed all the investigations as part of a coordinated effort by Democrats to undermine his candidacy.

In a post on his Truth Social site on Saturday, Trump again called the Georgia investigation a “witch hunt.”

Willis is expected to charge multiple people, possibly by using the state’s broad racketeering statute. Her investigation began soon after Trump made a phone call to the state’s top election official, Republican Brad Raffensperger, and urged him to “find” enough votes to alter the outcome.

In addition to efforts to pressure Georgia officials, Willis has examined a breach of election machines in a rural county and a plot to use fake electors in a bid to capture the state’s electoral votes for Trump rather than Biden.

Chidi, the journalist, has written about happening upon a secret meeting of those electors at the state capitol in December 2020.

Duncan, the former head of the state Senate, publicly criticized Republican lawmakers and Trump associates who pushed the false narrative that the election was tainted by fraud.