Former Port Authority official David Wildstein remains a key figure in the Bridgegate scandal.

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Last summer, Gov. Chris Christie's deputy chief of staff Bridget Kelly emailed Wildstein writing, "Time for some traffic problems in Fort Lee." Wildstein replied, "Got it."

Wildstein has since resigned, and Kelly has been fired. Wildstein claims he'd give answers to a legislative committee investigating the scandal if he's given immunity, but that's not likely to happen.

"The legislature can't give him immunity from criminal prosecution," said state Sen. President Steve Sweeney (D-West Deptford). "If he had something to say, then there are ways of him saying it privately that would justify immunity, or going to the federal authorities to give him or grant him that immunity."

The unannounced George Washington Bridge access lane closures in Fort Lee in September led to massive traffic jams, and the ensuing controversy continues to rock the Christie administration. A total of 20 subpoenas have been issued by a joint Senate and Assembly committee. Documents are due Feb. 3. The federal government has also issued subpoenas that are due Feb. 5.

One theory is the lanes were closed to retaliate against Fort Lee's Democratic mayor for refusing to endorse Christie's re-election bid. Another theory is that the closures are tied to a development project the governor favors.

In previous testimony before the Assembly panel investigating Bridgegate, Wildstein refused to answer questions, citing his Fifth Amendment rights. In that case, he also said he would testify if given immunity.

"To grant immunity without having any idea what he has to say doesn't make any sense," Sweeney said. "We're going to say, 'OK, you've got immunity,' and he says, 'Well, I don't remember anything.' We're not doing that."

There is also the concern that if Wildstein is given immunity, he could take the blame for the entire Bridgegate scandal -- thereby letting anyone else who might have been involved off the hook.

"You have to make sure that whatever he's willing to testify to is going to be thorough and accurate, and not just the ability to kill an investigation," Sweeney said.