The Georgia prosecutor investigating potential criminal interference in the 2020 presidential election is considering requesting that former President Donald Trump testify under oath to a grand jury, while several people already subpoenaed as part of the probe have received letters informing them that they're at risk of being indicted.

The developments underscore the accelerating nature of Fulton County District Attorney Fani Willis' investigation and the key decisions that may lie ahead for prosecutors who for more than a year have been scrutinizing efforts by Trump and his allies to undo his election loss in Georgia.

Jeff DiSantis, a spokesman for Willis, told The Associated Press that Willis is considering subpoenaing Trump to testify before a special grand jury. Such a demand would almost certainly trigger an immediate court fight, including potentially over Trump's constitutional protections against self-incrimination. Yahoo had reported earlier Friday that Willis is considering requesting Trump's testimony.

Meanwhile, some people who had been subpoenaed have subsequently received so-called target letters, according to a person familiar with the matter who insisted on anonymity to discuss an ongoing investigation. Prosecutors generally issue such letters to inform people they've been investigating that they have developed evidence against them and that they're in jeopardy of being criminally charged.

The person who confirmed the issuance of the target letters, which were first reported by Yahoo, would not identify any of the recipients.

Also Friday, state Sen. Burt Jones, who's the Republican nominee for lieutenant governor in November's general election, filed a motion to disqualify Willis and her office from the investigation. His lawyers argue that Willis has a conflict of interest because she is an active supporter of Jones' Democratic opponent.

Jones' campaign spokesman Stephen Lawson declined to comment when asked if Jones had received a target letter.

The special grand jury was seated in May at Willis' request and has been investigating whether Trump and others illegally tried to meddle in the 2020 election in Georgia as the Republican desperately tried to cling to power after his loss to Democrat Joe Biden. Trump continues to insist that the election was stolen, despite the fact that numerous federal and local officials, a long list of courts, top former campaign staffers and even his own attorney general have all said there is no evidence of the fraud he alleges.

Willis has confirmed that the investigation's scope includes a Jan. 2, 2021, phone call between Trump and Georgia Secretary of State Brad Raffensperger. During that call, Trump urged Raffensperger to "find" enough votes to overturn his loss in the state.

"All I want to do is this. I just want to find 11,780 votes, which is one more than we have," Trump said during that call. "Because we won the state."

Trump has denied any wrongdoing and has repeatedly described his call to Raffensperger as "perfect."

Willis, a Democrat, has also said that her team is looking into a November 2020 call that U.S. Sen. Lindsey Graham, R-S.C., made to Raffensperger and false claims of election fraud that were made by former New York mayor and Trump attorney Rudy Giuliani and others during December 2020 legislative committee hearings at the state Capitol.

Graham and Giuliani are among the Trump associates Willis is trying to force to go to Atlanta to testify before the special grand jury.

Willis has also indicated that she's interested in the actions of a group of 16 Georgia Republicans who signed a certificate falsely stating that Trump had won the state when it was actually Democrat Joe Biden who got the most votes. They cast their fake electoral votes behind closed doors at the Georgia Capitol on Dec. 14, 2020, the same day that the actual Democratic electors met to cast their votes.

Jones was among those who signed the certificate, which was then sent to Congress and the National Archives.

The motion filed Friday by his lawyers says that Willis donated to the campaign of Democratic lieutenant governor nominee Charlie Bailey and last month hosted a fundraiser for him. It says that special prosecutor Nathan Wade also donated to Bailey. Willis, Wade and the entire Fulton County district attorney's office should be disqualified "from the investigation and prosecution of Mr. Jones," the motion says

"Their investigation of Mr. Jones in this case, by having him appear before a special purpose grand jury to testify about his conduct, is affected by political motivations evident by their joint interest in the success of Charles Bailey's political campaign," Jones' lawyers wrote.

The special grand jury cannot issue indictments. Instead, it is to issue a report with its findings and recommendations, and it will then be up to Willis to decide whether to seek an indictment from a regular grand jury.

The motion notes that the special grand jury report "is likely to come out right before the election." If the judge will not disqualify Willis, Wade and the district attorney's office, the motion asks that the judge order that the special grand jury report be sealed until after the election "to prevent any improper and undue influence therein."

"Burt is more than happy to perform his civic duty and answer questions — but not from a prosecutor with such blatant conflicts of interest," Lawson, the campaign spokesman, said in a statement.

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