Schar is a former assistant U.S. attorney who served as lead investigator and prosecutor in the 2010-2011 investigation and trial of former Illinois Gov. Rod Blagojevich, a Democrat who is serving a 14-year federal prison sentence for corruption.
Schar will help New Jersey lawmakers in their investigation of an incident in September in which aides to Gov. Chris Christie were involved in ordering the closure of access roads to the George Washington Bridge, which connects Fort Lee, N.J., with New York.
Initially, Christie administration officials said the closure was part of a traffic study, but the recent release of official emails threw the official explanation into question. New Jersey Democrats have suggested the lane closures were a form of political retribution, but no clear motive has been established.
Christie -- widely regarded as a leading contender for the Republican presidential nomination 2016 -- has fired several top aides and has denied any involvement in or knowledge of the lane closures. In his State of the State address in Trenton Tuesday, the governor said he will cooperate with all "appropriate" investigations into the matter.
Assemblyman John Wisniewski, chairman of the legislative committee investigating Bridgegate, said he looks forward to working with Schar "as the committee ramps up its investigation into these concerns about public safety and abuse of power."