Law enforcement veterans are expressing deep concerns that the Trump Justice Department's criminal investigation into former CIA Director John Brennan is being systematically stacked with politically motivated personnel who are intent on a partisan indictment.Brennan is the subject of two criminal probes being led by the Miami-area U.S. Attorney's Office. One is weighing allegations that he lied to Congress in 2023 about the U.S. intelligence community's assessment on Russian interference in the 2016 election. The second is a sprawling "grand conspiracy" probe examining whether Obama- and Biden-era officials were part of a long-running conspiracy to keep President Trump out of political office.Last month, the Justice Department abruptly removed the senior career prosecutor who was overseeing the Brennan case after she expressed concerns about the strength of the evidence and replaced her with Joseph DiGenova, a staunch Trump ally, to run both investigations.On Tuesday, DiGenova's wife, Victoria Toensing, a former federal prosecutor, conservative commentator and staunch Trump ally, was sworn in as a federal prosecutor in the Southern District of Florida. DiGenova declined to say whether she is working on the Brennan and grand conspiracy cases, but a source with direct knowledge confirmed she is. Now, multiple sources are raising concerns that some of the line prosecutors and FBI agents assigned to the case may harbor underlying political motivations that could cast doubt on their ability to conduct an impartial investigation. One of the FBI agents, for example, once sought to investigate whether Italian military satellites hacked American voting machines in the 2020 election. A second agent was involved in the recently botched criminal prosecution of former FBI Director James Comey, sources told CBS News, and also lobbied senators to confirm Kash Patel to be FBI director. Those two agents — Rose Marketos and Jack Eckenrode — both served on the Director's Advisory Team at the FBI, which was set up by Patel and staffed by agents from around the country who support his policy goals, according to sources familiar with the matter.