barack obama justice department loretta lynch take order big development justice department grant immunity former state department staffer work hillary rodham clinton private email server sign fbi investigation possible criminal wrongdoing progressing.a senior u.s. law enforcement official say fbi secure cooperation bryan pagliano work clinton 2008 presidential campaign set server new york home 2009.as fbi look wrap investigation come months agents likely want interview clinton senior aid decision use private server set whether participants know send classify information email current former officials said.read washington post obama justice dept grant immunity staffer set clinton e-mail server