Former CIA director John Brennan has been subpoenaed to testify before a grand jury in Fort Pierce, Florida, as part of a Department of Justice (DOJ) investigation into whether former law enforcement and intelligence officials conspired against former President Donald Trump. The subpoena, revealed by Brennan’s attorney, Ken Wainstein, in a court filing, requires Brennan to appear on October 15. The investigation is examining whether government officials who have probed Trump over the past decade—such as those looking into Russian election interference in 2016 and his recent possession of classified documents at his Mar-a-Lago estate—worked together to infringe on Trump’s civil rights. This subpoena is one of several issued recently as part of a broader inquiry. Wainstein stated that prosecutors informed him Brennan remains a target in a Washington-based investigation into whether he lied to Congress in 2023. Brennan and his legal team have consistently denied these allegations. Earlier this year, subpoenas for grand jury testimony in that probe were issued but later withdrawn in favor of voluntary interviews. The subpoena was issued on the same day that Joe diGenova, the lead prosecutor in the "grand conspiracy" investigation, abruptly resigned. A person familiar with the situation described the resignation as stemming from dissatisfaction within the DOJ and the White House over the pace and management of the investigation. The DOJ has not publicly named a replacement for diGenova. The member of the investigative team who spoke with Wainstein was Kurt Olsen, a lawyer who previously advocated for the DOJ to support Trump’s claims that the 2020 election was stolen. The subpoena was disclosed just hours before a court hearing in Washington, where Brennan is seeking a court order to preserve all records from the investigations targeting him. Brennan argues that these documents would be crucial for him to challenge any potential indictment on the grounds of vindictive prosecution, meaning he believes the investigations are politically motivated rather than based on legitimate legal grounds.