A former FBI agent who was tapped to help investigate Missouri’s governor pleaded guilty on March 23 to tampering with evidence, deciding not to go to trial on seven counts. William Don Tisaby, 69, now a private investigator, was hired by St. Louis Circuit Attorney Kimberly Gardner to help probe Missouri Gov. Eric Greitens over an alleged invasion of privacy. Greitens resigned in 2018 after the investigation was opened. Tisaby was indicted on seven felonies, including perjury and evidence tampering, in 2019. Tisaby acknowledged in the plea deal that he said in a deposition that certain documents did not exist when, in fact, they did, Robert Russell, the special prosecutor in the case, told reporters outside the courthouse in St. Louis after the deal was reached. “He’s admitting to hiding or at least testifying that the notes that Ms. Gardner gave to him were not given to him by testifying that …