...Baumgartner had been working alongside Simpson as a Russian translator for a New York law firm defending a Russian holding company, Prevezon, in a money-laundering suit filed by the US Justice Department in Manhattan. Owned by Denis Katsyv, a Putin-tied oligarch, Prevezon was sanctioned under the Magnitsky Act. Also defending Prevezon was Natalia Veselnitskaya, a Russian lawyer who Simpson helped lobby Congress to repeal the Magnitsky Act by attacking William Browder, the banker-turned-human-rights-activist who championed it. “He speaks Russian,” Simpson said of Baumgartner, after Senate Judiciary Committee staff asked about “subcontractors” he’d hired. “So he would work with the lawyers...