TRENTON - (AP) - Halfway into his term, Gov. Chris Christieis shuffling his top staff. Administration officials tell The Associated Press that chief ofstaff Richard Bagger is leaving to take a job in the private sectoron Jan. 31. Deputy Chief of Staff Kevin O'Dowd will move to takeBagger's place. Homeland Security director Charles McKenna will move over tobecome Christie's chief counsel. He'll replace Jeff Chiesa, whomChristie is nominating for Attorney General. O'Dowd and McKenna used to work for Christie at the U.S.Attorney's Office. O'Dowd was chief of the securities and healthcare fraud unit. McKenna led the criminal division, working on highprofile cases that included the Sept. 11 terrorist attacks and thecase of slain Wall Street Journal reporter Daniel Pearl.