Here’s a timeline of the investigation in Georgia.

The criminal investigation of former President Donald J. Trump and his allies in Georgia has its roots in activities that began shortly after he lost the 2020 election. So far, there have been two key investigatory threads: a plan to send an alternate slate of electors from states that Mr. Trump lost, including Georgia, and Mr. Trump’s request that Georgia’s secretary of state find the votes he needed to flip the state’s 16 electoral votes to him instead of Joseph R. Biden Jr.

Here’s a look at some of the key events connected to the investigation.

Nov. 18, 2020: Just over two weeks after Election Day, an outside adviser to the Trump campaign, Kenneth Chesebro, sends the first of three memos laying the groundwork for using the Electoral College system to affect the outcome of the race.

Dec. 5: Mr. Trump calls Gov. Brian Kemp, a Republican, and urges him to circumvent the normal process for awarding electoral votes and allow Georgia’s lawmakers to do it instead.

Dec. 6: Mark Meadows, the White House chief of staff, shares one of those memos with Jason Miller, a senior adviser on the Trump campaign. In the next few days, Mr. Trump decides to pursue the plan to offer alternate electors, according to the findings of the House committee that investigated the Jan. 6 attack on the Capitol.

Dec. 7: Georgia elections officials recertified the results of the state’s presidential race after a recount reaffirmed Joseph R. Biden Jr.’s victory over President Trump, the third time that results showed that Mr. Trump had lost the state.

Dec. 14: Fake slates of electors from seven states that Mr. Trump lost on Election Day, including Georgia, ostensibly cast votes for Mr. Trump.

Jan. 2, 2021: Mr. Trump places a phone call to Georgia’s secretary of state, Brad Raffensperger, a Republican, asking him to “find” the nearly 12,000 votes he would have needed to win the state’s electoral votes. Mr. Trump also suggested that failing to act on the fraud he falsely claimed had occurred could constitute “a criminal offense.”

Jan. 6, 2021: Despite the attack on the Capitol by a Trump-supporting mob, Mr. Biden’s victory is certified by Congress.

February 2021: Fani T. Willis, the district attorney of Fulton County, Ga., opens an inquiry into the actions of Mr. Trump and his allies. Over the course of the investigation, her office will send so-called target letters to nearly 20 people who could face charges, including Rudolph W. Giuliani, Mr. Trump’s former personal lawyer, and David Shafer, the head of the Georgia Republican Party.

November 2021: Mr. Raffensperger, in a book, writes: “For the office of the secretary of state to ‘recalculate’ would mean we would somehow have to fudge the numbers. The president was asking me to do something that I knew was wrong, and I was not going to do that.”

January 2022: Ms. Willis asks the chief judge of the Fulton County Superior Court to convene a special grand jury, writing in a letter: “The District Attorney’s Office has received information indicating a reasonable probability that the State of Georgia’s administration of elections in 2020, including the State’s election of the President of the United States, was subject to possible criminal disruptions.”

May 2022: A special grand jury is sworn in as part of the investigation. Over the next six months, it will hear testimony from witnesses, some of whom fight the grand jury’s subpoenas, including Senator Lindsey Graham of South Carolina, a key Trump ally.

Jan. 9, 2023: The special grand jury concludes its work. Although it is not empowered to issue indictments, it compiled its findings into a report that was reviewed by the 20 judges on the Superior Court of Fulton County. The grand jury asks for its report to be made public.

Jan. 24: Ms. Willis’s office asks a judge to keep the grand jury’s report secret, saying that she was “mindful of protecting future defendants’ rights.”

Feb. 13: Judge Robert C.I. McBurney of Fulton County Superior Court issues a ruling saying he will release part of the grand jury’s report.

Feb. 16: Judge McBurney releases small portions of the report: The introduction and conclusion, and a passage saying that the jury believed perjury may have been committed by one or more of the 75 witnesses who testified in the inquiry.