A trove of documents provided to House impeachment investigators by Lev Parnas, an associate of Trump lawyer Rudy Giuliani, appears to show former top Ukraine prosecutor Yuri Lutsenko offering Giuliani damaging information on Joe and Hunter Biden in exchange for the firing of then–U.S. ambassador Marie Yovanovitch.Lutsenko was critical of Yovanovitch due to her support for an anti-corruption institution based in Ukraine, as well as because the ambassador had been critical of Lutsenko and his office."It’s just that if you don’t make a decision about Madam — you are calling into question all my declarations. Including about B,” Lutsenko wrote to Parnas in Russian in a Whatsapp message from March 22. "Madam" likely refers to Yovanovitch, while it is unclear if "B" designates Biden or Burisma, the Ukrainian company on whose board Hunter Biden sat from 2014 to early 2019.Lutsenko, who was in the midst of an investigation into Burisma, updated Parnas four days later, writing that he had found evidence of money transfers pertaining to "B.""And here you can’t even remove one fool :(" Lutsenko told Parnas via text message."She’s not a simple fool[,] trust me," Parnas wrote back. "But she’s not getting away."The documents also reveal that Parnas's associate, Connecticut businessman and congressional candidate Robert Hyde, was in contact with some unidentified person who was surveilling Yovanovitch.During her testimony before Congress last year, Yovanovitch speculated that Giuliani and his associates were working to have her fired in order to install an ambassador who would be more amenable to their corrupt business dealings in Ukraine.The documents are likely to breath new life into the Democrat-led impeachment process against President Trump, just as the House plans to vote to transfer the impeachment articles to the Senate for trial.The contours of the trial are as yet unclear. Republicans in the Senate and the Trump administration have vacillated between calls to allow witnesses to testify at the trial and a desire to dismiss the charges without summoning witnesses at all.