New Jersey Gov. Chris Christie's (R) former campaign manager will plead the Fifth Amendment when he is asked about his role in an apparent plot to create a traffic jam in Fort Lee, N.J., according to a filing from his lawyer.

The campaign manager, Bill Stepien, was one of two people disciplined for his actions related to the access lane closures, shortly after the apparent scheme was disclosed in a series of e-mails and text messages. While then-deputy Christie chief of staff Bridget Kelly was fired, Christie told Stepien to end his contract with the Republican Governors Association, which Christie leads, and not run for state party chairman.

Stepien was not directly implicated in the incident, but he spoke with a Christie appointee at the Port Authority of New York and New Jersey after the fact.

The Christie appointee, David Wildstein, repeatedly pleaded the Fifth Amendment when asked about his actions by a state legislative committee earlier this month.

In another major development Friday, a letter from Wildstein's lawyer alleges Christie knew about the lane closures and says Christie hasn't been honest about what he knew.

Prior to Wildstein's letter, Christie had not been implicated in the incident, in which Kelly and Wildstein sought to close two of three access lanes from Fort Lee to the George Washington Bridge, creating a massive bottleneck in Fort Lee. There is still no public evidence that Christie knew about the plot.

Federal investigators and a panel of state legislators are both investigating the matter.

Updated at 5:31 p.m.

2014-01-31 Letter to Reid J. Schar