As thousands of subpoenaed documents begin rolling in concerning Chris Christie's bridge scandal, two of his aides have pleaded the fifth to avoid turning over documents to  investigators. Both Bridget Kelly and Bill Stepien have invoked their constitutional right against self-incrimination.

Kelly, perhaps most directly tied to "some traffic problems in Fort Lee," invoked both the Fourth and Fifth amendments in a letter from her lawyer to investigators. From The New York Times:

The letter said that the panel’s request “directly overlaps with a parallel federal grand jury investigation.” It also contended that giving the committee “unfettered access” to her diaries, calendars and electronic devices could “potentially reveal highly personal confidential communications” unrelated to the bridge scandal.

Bill Stepien, a former campaign manager and deputy chief of staff, also pleaded the fifth regarding his subpoena, also citing the federal investigation into the lane closings (reminder: this all concerns lane closings on a bridge). Stepien's lawyer wrote:

there is a very real possibility that his act of producing documents and things responsive to the subpoena might compel him to furnish a link in the chain of evidence that could be used to ensnare him in … a criminal prosecution — and thus force him to become a witness against himself.

The objections could take months to be resolved by the courts. Meanwhile, investigators are sifting through piles of documents as they look into the incident and who, if anyone, might be culpable. In a radio interview on Monday night, Christie said his administration was cooperating fully and denied any personal involvement.