Sidney Powell, an attorney who was a key figure in former President Donald Trump's alleged efforts to overturn the results of the 2020 election, pleaded guilty to six misdemeanor counts after reaching an agreement with prosecutors in Fulton County, Georgia.

Powell appeared in the Superior Court of Fulton County in Atlanta on Thursday, where a prosecutor laid out the terms of the plea deal. In exchange for her pleading guilty, Powell was sentenced to six years on probation and must pay a $6,000 fine and $2,700 in restitution to the state of Georgia. Judge Scott McAfee, who is overseeing the case, signed off on the agreement at the hearing.

Powell is also required to testify "truthfully against any and all co-defendants in this matter," McAfee said.

Powell was among the conservative lawyers who pushed baseless claims of widespread fraud in the 2020 election, endorsing outlandish theories of foreign interference and ballot manipulation to try to reverse the results. She participated in a contentious meeting at the White House in December 2020, during which White House lawyers confronted her and lawyer Rudy Giuliani about their election claims.

She and 18 others, including Trump, were charged by a grand jury in Fulton County in August. Powell initially faced seven charges and pleaded not guilty. Prosecutors agreed to dismiss the charges in the original indictment as part of the plea deal.

The guilty plea comes shortly before Powell and Kenneth Chesebro, another co-defendant, were set to go on trial. Chesebro has pleaded not guilty, and jury selection for his trial will begin as scheduled on Friday. An attorney for Chesebro declined to comment on Powell's plea.

Powell's guilty plea

Court documents filed in Fulton County Superior Court showed Powell pleaded guilty to six counts of conspiracy to commit intentional interference with performance of election duties. All six counts were related to a scheme in which Powell coordinated with a data company, SullivanStrickler, to access election data from Coffee County, Georgia.

"The purpose of the conspiracy was to use Misty Hampton's position to unlawfully access secure elections machines in Coffee County, Georgia," Assistant District Attorney Daysha Young explained at the hearing, referring to the elections director in the county who has also been charged. The objective was to "willfully tamper with electronic ballot markers and tabulating machines" and remove voting data from elections systems. Powell entered into a contract with SullivanStrickler to travel to Coffee County to obtain the data.

Seated beside her attorney Thursday, Powell said she understood the terms of the plea agreement and admitted to the facts laid out by the prosecutor.

Powell is also barred from communicating with "co-defendants, witnesses and media until this case has been completely closed against all defendants." She is required to hand over documents to prosecutors and wrote an apology letter to Georgia citizens as part of the deal.

When asked if anyone has forced, threatened or promised her anything in exchange for her guilty plea, Powell responded, "other than what is recited in the documents, no."

Powell is the second defendant to plead guilty in the sprawling case. Scott Hall, a bail bondsman, became the first when he changed pleaded guilty to five misdemeanor counts at the end of September. He was sentenced to five years probation, a $5,000 fine and 200 hours of community service. 

Trump and the rest of the co-defendants have pleaded not guilty and denied all wrongdoing. 

What the plea could mean for the special counsel's case

Powell's guilty plea in Georgia could have implications for her involvement in special counsel Jack Smith's federal case against Trump in Washington, D.C., according to Scott Fredericksen, a former federal prosecutor and independent counsel. He said Powell's plea may be "the single most important development" in either of the probes dealing with the aftermath of the 2020 election.

Powell was identified by CBS News as likely being the unnamed and unindicted individual known as "Co-conspirator 3" in Trump's federal indictment, in which he was accused of engaging in alleged schemes to overturn Joe Biden's victory in 2020.

"If she is cooperating with Willis, she should be available to be interviewed by Smith and testify," Fredericksen said. "She may insist on some kind of protection or immunity from Smith in Smith's case, but her ability to testify directly to what Trump may have said about the plans to overthrow the election could make her a critical witness."

Trump has pleaded not guilty in that case as well, and says the four ongoing prosecutions against him are politically motivated.

Melissa Quinn, Faris Tanyos and Graham Kates contributed to this report.