(CNN) – One day after an ex-official invoked his Fifth Amendment rights at a state legislative hearing on the New Jersey bridge scandal, CNN's Chief National Correspondent John King reports the legislative committee's chairman and staff are taking steps to subpoena Bridget Anne Kelly, a second key witness and Gov. Chris Christie's ex-deputy chief of staff.
Christie announced Thursday that he fired Kelly after recently emerged emails indicated she played a major role in the decision to shut down multiple access lanes to the George Washington Bridge as a political vendetta. The lane closures caused a massive traffic jam in Fort Lee, New Jersey, for nearly a week in September.
The emails showed that Kelly and David Wildstein, a former Port Authority official and political appointee of Christie's, worked together to get the lanes closed. Wildstein resigned last month and appeared before the panel on Thursday under a subpoena but didn't answer any questions.
For her part, Kelly would be considered a key witness to the committee if subpoenaed and to a criminal investigation that is in its early stages.
Christie said he didn't know until Wednesday that the lane closures were a politically-motivated act of retaliation against the Fort Lee mayor, who didn't endorse Christie last year as the Governor ran for re-election.