Joe diGenova, a prominent ally of former President Donald Trump, has resigned from his position leading a Justice Department investigation into alleged conspiracies against the former president. DiGenova, 81, announced his departure from the wide-ranging probe, which has been active in the Southern District of Florida, but declined to comment on the reasons for his resignation.

Sources familiar with the decision indicated that diGenova's exit stemmed from mounting frustration from both the Justice Department and the White House regarding the investigation's progress and management. An unidentified source told NBC News that leadership at the Justice Department felt the probe was not moving quickly enough, despite diGenova being provided with a team of lawyers from Washington.

Responding to criticism of his handling of the investigation, diGenova told The New York Post that "If you want indictments where there´s no evidence, you have an ethical problem." He later clarified that the comment was taken out of context, stating, "There's plenty of evidence in all of these cases to prove the theories of prosecution. It just takes time to get there, and some people want to get there a little faster than others - and you can´t do that."

Initially, diGenova had expressed confidence in bringing charges swiftly after being brought into the Justice Department in April. He vowed to secure indictments within 30 days, reportedly aiming to pursue charges against former CIA Director John Brennan for allegedly lying to Congress. However, the investigation expanded in scope, with one source describing it as "going down 900 rabbit holes." Career lawyers reportedly expressed doubts about the likelihood of criminal charges and were sometimes sidelined.

The investigation's objective was to link separate inquiries involving Trump, including allegations of Russian interference in the 2016 election, charges related to the January 6, 2021, Capitol riot, and his handling of classified documents at his Mar-a-Lago estate, into a single conspiracy orchestrated by law enforcement and intelligence officials. The probe, promoted by the White House and supported by Trump's base, has proceeded unevenly since its inception a year prior.

Despite the lack of charges, the investigation has reportedly seen some recent developments. Subpoenas have been issued to federal agents involved in the August 2022 Mar-a-Lago raid, according to The New York Times. Investigators have also focused on the U.S. intelligence community's assessment of Russian interference in the 2016 election, a topic that has long been a grievance for Trump.

Previous inquiries, including a Justice Department special counsel investigation into Russian election interference and reviews by the Justice Department's inspector general, found widespread Russian interference but no evidence of a criminal conspiracy between Moscow and the Trump campaign. While these reviews identified significant errors in the FBI's handling of the Trump-Russia probe, they did not find evidence of criminal misconduct by senior law enforcement officials.

This is not the first time the conspiracy investigation has faced internal challenges. In April, career prosecutor Maria Medetis Long stepped down, reportedly due to doubts about the potential for criminal charges against John Brennan. DiGenova took over the leadership following her departure. A hearing is scheduled for Monday in Washington, D.C., concerning a lawsuit filed by Brennan against the Justice Department, seeking a court order to preserve records from the investigation and challenging any potential indictment on grounds of vindictive prosecution.

DiGenova, who served as U.S. attorney for the District of Columbia during the Reagan administration, has been a vocal Trump supporter, advocating for his efforts to overturn the 2020 election results and frequently asserting that Trump was the victim of an intelligence community conspiracy. In past public statements, including on a podcast with Rudolph Giuliani, diGenova suggested potential targets for the investigation, naming former President Barack Obama and New York Attorney General Letitia James, and proposing they be included in a "massive conspiracy count."