A Georgia judge ordered Rudolph W. Giuliani to testify in Atlanta next month in an ongoing criminal investigation into election interference by former President Donald J. Trump and his advisers and allies, according to court filings released on Wednesday.
Some out-of-state witnesses in the case have gone to court to challenge subpoenas or other legal filings seeking to compel their testimony. But after Mr. Giuliani failed to show for a hearing last week in Manhattan, where the matter was to have been adjudicated, Judge Robert C. I. McBurney of the Superior Court of Fulton County ordered him to appear before a special grand jury in Atlanta on Aug. 9.
Mr. Giuliani, who spearheaded efforts to keep Mr. Trump in power as his personal lawyer, has emerged as a central figure in the Georgia criminal investigation into efforts to overturn Mr. Trump’s 2020 electoral loss in the state. Fani T. Willis, the prosecutor in Fulton County leading the investigation, has indicated that she is considering conspiracy or racketeering charges, which could take in a broad spectrum of people engaged in multiple efforts to sway the election results.
Her office worked with the office of Alvin Bragg, the district attorney in Manhattan, to secure Mr. Giuliani’s testimony, and she said in a statement that she was “grateful to the prosecutors and investigators” in Mr. Bragg’s office for their assistance.
Mr. Giuliani’s lawyer did not immediately respond to a request for comment.
A special grand jury has been meeting regularly in Atlanta to hear testimony and review documents and videos that may shed light on the multipronged effort to put Georgia in Mr. Trump’s win column. Among the acts under consideration are an infamous postelection phone call that Mr. Trump made to Brad Raffensperger, the Georgia secretary of state, asking to “find” enough votes to secure his victory.
Mr. Giuliani appears to be of interest for a number of reasons, including his participation in a scheme to create slates of pro-Trump presidential electors in numerous states including Georgia. In court filings this week, it was revealed that all 16 pro-Trump electors in Georgia had been informed by the Fulton County District Attorney’s office that they could face charges.
Mr. Giuliani also appeared in person before two Georgia state legislative committees in December 2020, where he spent hours peddling false conspiracy theories about secret suitcases of Democratic ballots and corrupted voting machines. He told state legislators, “You cannot possibly certify Georgia in good faith.”
Legal experts have said the Georgia investigation may prove to be particularly perilous for Mr. Trump and his allies. Though the grand jury proceedings are secret, a number of details have emerged in recent days that hint at the scope of the investigation. Among the pro-Trump electors who learned they could be indicted are David Shafer, the chair of the state Republican Party, and State Senator Burt Jones, the party’s nominee for lieutenant governor. Another Republican state senator, Brandon Beach, was also informed that he is a potential target.
Prosecutors are seeking testimony from Senator Lindsey Graham of South Carolina, a Trump ally who also called Mr. Raffensperger, and Representative Jody Hice, a hard-right Georgia Republican who has embraced false narratives about election fraud in Georgia and who helped lead efforts in Congress to help keep Mr. Trump in power.
William K. Rashbaum and Jonah E. Bromwich contributed reporting.