Former Hillary Clinton IT specialist Bryan Pagliano, a key witness in the email probe who struck an immunity deal with the Justice Department, has told the FBI a range of details about how her personal email system was set up, according to an intelligence source close to the case who called him a “devastating witness.” The source said Pagliano told the FBI who had access to the former secretary of state’s system – as well as when – and what devices were used, amounting to a roadmap for investigators. "Bryan Pagliano is a devastating witness and, as the webmaster, knows...