Jonathan Bachman/Reuters - U.S. Attorney General Eric Holder speaks at a news conference in New Orleans November 15, 2012.Attorney General Eric H. Holder Jr. on Thursday defended the Justice Department’s handling of the investigation that ledDavid H. Petraeus to resign as CIA director, saying that the department was right to keep the inquiry secret from the White House until after last week’s presidential election.Holder’s first public comments on the controversy came as the CIA opened an internal inquiry of Petraeus’s conduct during his 14-month tenure as director. The move means that there are three active investigations related to a scandal...