Last week, Gov. Christie fired a top aide and dismissed a close political adviser after e-mails subpoenaed by Wisniewski's committee revealed an apparent plot by the Republican governor's allies to jam traffic in Fort Lee, where the Democratic mayor did not endorse Christie's reelection.
Christie has denied any knowledge of the plot to create traffic. A Quinnipiac poll released Wednesday showed a majority of voters do not believe he was personally involved in ordering the lane closures, which were overseen by appointees at the Port Authority of New York and New Jersey.
The subpoena power used by Wisniewski's committee expired Tuesday with the start of the new legislative session. After Assembly leaders announced a special session Thursday to reauthorize subpoena powers and create a new committee, leaders in the Democratic-controlled Senate said they also planned to create a committee with the same authority.
Senate leaders have not yet announced appointments to their committee.
Both houses are scheduled to meet at noon Thursday.
The resolution before the Assembly would create a committee to investigate the finances and operations of the Port Authority, the closure of access lanes to the George Washington Bridge, and "any other matter raising concerns about abuse of government power or an attempt to conceal abuse of government power."
Schar - who is cochair of the white collar defense practice at Jenner & Block - and his firm will provide the Assembly investigatory committee needed guidance to avoid crossing "jurisdictional lines," Wisniewski said Wednesday. In addition to the legislative investigation, the U.S. Attorney's Office has said it is reviewing the case to see whether federal laws were violated.
Schar will also ensure that the committee's inquiries are "effective and efficient," and would withstand any future court challenge, Wisniewski said.
Wisniewski did not know the expected cost of Schar's services, but said the firm "made a significant concession in hourly rate." Tom Hester, a spokesman for Assembly Democrats, said details were still being worked out Wednesday evening.
Jenner & Block also has offices in New York, among other cities.
Wisniewski said Schar's role "is being determined as we move forward," but that the assemblyman would continue to lead questioning, as he did with the Port Authority officials subpoenaed by the committee. A spokesman for Jenner & Block said Schar was unavailable for comment Wednesday and directed future inquiries to Hester.
More subpoenas may be issued as soon as Thursday. Wisniewski has said his inquiry will include Bridget Anne Kelly, the aide fired by Christie after the disclosure of an e-mail she sent that read: "Time for some traffic problems in Fort Lee."
He has also indicated the investigation will include Bill Stepien, Christie's former campaign adviser, implicated in the e-mails.
Kevin Marino, a Chatham, N.J., attorney, confirmed Wednesday that he had been retained to represent Stepien.
The lawmakers appointed to the Assembly investigatory committee include Majority Leader Louis D. Greenwald (D., Camden) and Paul Moriarty (D., Gloucester). Speaker Vincent Prieto (D., Hudson) appointed the Democrats, while Minority Leader Jon Bramnick (R., Union) appointed the Republicans.
Mhanna@phillynews.com; 609-989-8990; @maddiehanna