(CNN) -- Chris Christie's administration got outside legal help on Thursday as a special state legislative committee decided to issue 20 subpoenas to launch its formal investigation of a scandal over alleged political retribution by top aides to the New Jersey governor.
The subpoenas for 17 individuals and three organizations seek documents for now, said Democratic Assemblyman John Wisniewski, chairman of the panel.
He refused to identify any recipients, saying they should learn of their subpoenas through being served instead of the news media.
But CNN has obtained some of the names of those subpoenaed, including top current and former Christie administration officials.
According to a source familiar with the subpoenas, among those served are: Kevin O'Dowd, Christie's chief of staff, David Samson, a close adviser, Bridget Anne Kelly, former deputy chief of staff, Bill Stepien, two-time Christie campaign manager, Charlie McKenna, Christie's chief counsel, Regina Egea, incoming chief of staff, Michael Drewniak, Christie's chief spokesman, Nicole Davidman Drewniak, Bill Baroni, top New Jersey official at Port Authority and Christie appointee, Patrick Foye, Port Authority executive director, Maria Comella, Colin Reed and Matt Mowers.
The committee is also looking at entities that had to do with the governor's re-election, the source said.
Christie fired Kelly and asked Stepien to leave his political operation after last week's release of explosive e-mails on the scandal.
One name not on the list so far is Christie, as Wisniewski said there was "no intention" to subpoena the Republican governor at this time because no documents made public so far showed a "direct link" to him.
Christie's office announced earlier his administration retained an outside law firm to help deal with the scandal involving traffic gridlock around the George Washington Bridge in Fort Lee last September.
E-mails made public last week suggested the lane closures that caused four days of jammed roads were orchestrated by top Christie aides to punish the Democratic mayor of Fort Lee for not endorsing the governor's re-election.
Also Thursday, the New Jersey Senate announced its own investigation in coordination with Wisniewski's panel, widening the political response to the controversial closing of access lanes to the nation's busiest bridge.
U.S. Attorney Paul J. Fishman is also looking into the bridge matter, bringing the total number of investigations to four, including an internal review by Christie's office.
Christie has promised cooperation with "appropriate" investigations of the matter, which could harm the presidential ambitions of the early front-runner for the Republican nomination in 2016.
He appeared to refer to the scandal when he told a Thursday morning event involving Superstorm Sandy recovery efforts that "no one, I can assure you, ever told me or anyone on my team that it was going to be easy."
"Whatever test they put in front of me, I will meet those tests," Christie said to applause.
Separately, a source close to Christie said the governor believes the investigations into the scandal will be a long process.
Christie does not intend to address the controversy in his inaugural address after he gets sworn in for a second term next week, the source told CNN's Dana Bash on condition of not being identified.
Documents made public last week suggested that top staffers in Christie's administration orchestrated the traffic logjam in Fort Lee as payback for the failure of the town's Democratic mayor to endorse the governor for re-election.
Those served will have two weeks to supply the requested documents, Wisniewski said, adding he expected his committee to meet again in mid-February to consider what it had received and possible next steps.
Christie said last week he knew nothing about any decision by aides to close highway lanes as political punishment, but Wisniewski and other Democrats label such a scenario as implausible.
The traffic gridlock occurred two months before Christie was re-elected to a second term.
In a document made public Thursday by Democratic Sen. Jay Rockefeller, chairman of the Senate Commerce, Science and Transportation Committee, the Port Authority of New York and New Jersey said a traffic study initially cited as the reason for the lane closures was an "aberrational" event conducted outside normal protocol.
The authority's response to questions from Rockefeller also said Christie's top appointee to the Port Authority leadership, David Wildstein, ordered the lane closures and suggested that he failed to heed warnings about their impact.
In addition, Wildstein ordered a Port Authority manager "not to communicate information about the lane reduction" to officials in Fort Lee and indicated "he would control the communication about the toll lane closures," according to the response.
Wildstein resigned from the Port Authority late last year as the controversy unfolded.
Despite polls showing Christie as the early favorite for the Republican presidential nomination two years from now, the bridge crisis has grabbed national attention and forced the normally combative governor to adopt a more conciliatory posture.
"Gov. Christie made clear last week that he will conduct an internal review to uncover the facts surrounding the lane closures in Fort Lee," his office said Thursday. "His administration is fully cooperating with the U.S. attorney inquiry and other appropriate inquiries and requests for information."
The Christie administration has retained Gibson, Dunn & Crutcher LLP as outside counsel in a move the administration hopes "will bring an outside, third party perspective to the situation."
Randy Mastro, a former assistant U.S. attorney for the Southern District of New York, will head the legal team.
Mastro has experience in organized crime cases and led the federal racketeering lawsuit that forced the International Brotherhood of Teamsters to hold democratic elections and to undergo court supervision. Mastro also is a former deputy mayor of New York.
On the other side, the Democratic-led State Assembly panel investigating the scandal will be assisted by attorney Reid Schar, a key figure in the federal prosecution of former Illinois Gov. Rod Blagojevich.
On Tuesday, Christie addressed the scandal briefly in his State of the State address, saying "mistakes were clearly made." He also tried to shift the focus to policy initiatives, repeatedly imploring Democrats to work with him.
The allegation of political payback first made by Democrats was subsequently magnified by e-mails that state legislators released last week.
Kelly's name appeared in e-mails with Wildstein, including one in which she wrote: "Time for some traffic problems in Fort Lee."
Other exchanges suggested that Stepien was aware of the maneuvering that led to traffic gridlock.
While the e-mails do not link Drewniak, the governor's spokesman, to the traffic jam scandal or even suggest it, they indicate that he had dinner with Wildstein two days before the transportation official resigned. Wildstein thanked Drewniak for his "sound advice," and the two men later e-mailed back and forth about how to announce his departure from the Port Authority.
Federal officials also are looking at New Jersey's use of $25 million in Superstorm Sandy relief funds for a marketing campaign promoting the Jersey Shore's recovery that featured Christie and his family.
In a statement Monday, Christie's office said the "Stronger than the Storm" campaign was part of an "action plan" approved by the Obama administration and developed with the goal of showing that the New Jersey Shore was open for business several months after the storm that devastated parts of the mid-Atlantic in October 2012.
The campaign took place the same year that Christie was running for re-election.
On Tuesday, the federal Housing and Urban Development agency described the investigation as a routine audit "and not an investigation of the procurement process."
CNN's Shimon Prokupecz, Ashley Killough, John King and Laura Koran contributed to this report.