Former CIA Director John Brennan has been subpoenaed to testify before a federal grand jury in Fort Pierce, Florida, on Oct. 15, as part of a sprawling Justice Department investigation into whether former law enforcement and intelligence officials conspired to violate President Donald Trump's civil rights, according to a court filing from Brennan's attorney.
Attorney Ken Wainstein said in the filing that the subpoena was signed by Joe diGenova, the prosecutor then leading the inquiry, and delivered to Brennan's legal team last week. DiGenova resigned days later amid friction with Justice Department leadership over how the investigation was being run. Kurt Olsen, another member of the prosecutorial team in the Southern District of Florida, has since told Wainstein that multiple grand jury investigations tied to Brennan remain active.
Two Tracks of Scrutiny
According to Wainstein's filing, Olsen described a broader, far-reaching investigation based in Fort Pierce that examines whether officials who investigated Trump over the past decade, including the 2016 Russia inquiry and the classified-documents case tied to his Mar-a-Lago estate, violated Trump's civil rights. Brennan is described as a subject of that inquiry. A separate, narrower investigation based in Washington is examining whether Brennan lied to Congress in 2023 about how the intelligence community's Russia assessment was produced, and Brennan remains a formally designated target in that probe.
Judge-Shopping Concerns
The subpoena's disclosure came hours before a Washington court hearing in a separate lawsuit Brennan filed seeking to preserve Justice Department communications, including Signal messages, related to the investigations. Wainstein used the filing to renew concerns that prosecutors are steering the case toward the Fort Pierce courthouse, the only federal courthouse in the Southern District of Florida with just one sitting judge: Aileen Cannon, a Trump appointee who dismissed the classified-documents case against Trump in 2024.
"There's a lot of really underhanded stuff going on," Wainstein said, pointing to the leadership turnover and case-assignment questions surrounding the investigation.
The 2016 Russia Assessment
Brennan led the CIA under President Barack Obama from 2013 to 2017 and was still director when U.S. intelligence agencies released a January 2017 assessment concluding that Russia had worked to help Trump defeat Hillary Clinton in the 2016 election. A subsequent investigation by special counsel Robert Mueller found that Russia had sought to assist Trump's campaign and that the campaign welcomed the help, though it did not establish enough evidence of a criminal conspiracy.
The current inquiry traces back to a criminal referral Rep. Jim Jordan, the Ohio Republican who chairs the House Judiciary Committee, sent the Justice Department last year, accusing Brennan of lying to Congress in 2023 about the assessment's preparation. It is one of several criminal probes the Justice Department has opened over the past year into people viewed as adversaries of the president, a group that has also included former FBI Director James Comey, whose indictment on unrelated charges was later dismissed.
Official Responses
Brennan and his legal team have repeatedly denied any wrongdoing and describe the investigation as politically motivated retaliation for his public criticism of Trump. In an earlier lawsuit seeking to preserve records tied to the case, Brennan's lawyers argued he was being singled out because of Trump's 'obsession with punishing him' for his conduct as CIA director and his constitutionally protected criticism of the president.
Brennan, who has not been charged with any crime, is due to appear before the Fort Pierce grand jury on Oct. 15.
