The investigation into the who and why of last fall’s George Washington Bridge gridlock is in high gear with the issuance of new subpoenas, the hiring of counsel and the formation of special legislative committees.

Twenty subpoenas from the newly formed Assembly Select Committee on Investigations went out on Thursday. Recipients were identified as they were served. As of Friday afternoon, 12 individuals and the governor’s office had been identified as having been served with documents-only subpoenas due on Feb. 3.

The Christie insiders served were Chief of Staff and Attorney General nominee Kevin O’Dowd; Chief Counsel Charles McKenna; lead spokesman Michael Drewniak; another spokesman, Colin Reed; Communications Director Maria Comella; O’Dowd’s expected successor, Regina Egea; and two other staffers, Christina Genovese and Evan Ridley.

Another subpoena was directed to Bill Stepien, who managed both of Christie’s gubernatorial campaigns. His lawyer, Kevin Marino, says he accepted service on Thursday evening of a subpoena for Stepien.

“We are reviewing the subpoena now and will respond to it as appropriate,” says Marino, of Marino, Tortorella & Boyle in Chatham.

Former Deputy Chief of Staff Bridget Kelly, author of the infamous “time for some traffic problems in Fort Lee” email, is also expected to be served with a subpoena. She was fired on Jan. 9.

The Port Authority figures subpoenaed were chairman David Samson of Wolff & Samson in West Orange, former director of interstate capital projects David Wildstein, who implemented the closures, and former deputy executive director Bill Baroni.

Wildstein and Baroni are Christie appointees who have already been subpoenaed and called to testify. Both resigned in December.

Emails produced by Wildstein in response to the earlier subpoena, released earlier this month, implicated them in the closures and/or cover-up, along with Kelly.

High-powered lawyers have been brought in on both sides.

The Christie administration announced Thursday it had retained Gibson, Dunn & Crutcher to assist with an internal review he promised in a Jan. 9 press conference on the scandal and to cooperate with a probe by the U.S. Attorney’s Office. The Gibson Dunn team will be led by former federal prosecutor Randy Mastro. An accompanying press release states the firm “will review best practices for office operations and information flow, and assist with document retention and production.” [ See related story.]

On Wednesday, Reid Schar of Jenner & Block in Chicago was hired as special counsel for the Assembly Select Committee. Its mission is described in a press release as “continuing the inquiry into questions surrounding the decision to close access lanes to the George Washington Bridge and other matters raising concerns about the abuse of government power.”

Other lawyers representing key figures are Alan Zegas of Chatham, for Wildstein, and Michael Himmel of Lowenstein Sandler in Roseland, for Baroni.

The explanation given by Wildstein and Baroni that the closures were part of a traffic study has been largely debunked.

On Thursday, U.S. Sen. Jay Rockefeller IV, chairman of the Senate Commerce, Science and Transportation Committee, announced that the Port Authority had provided “zero evidence that the purpose of these closures was to conduct a legitimate traffic study.”

Rockefeller, a West Virginia Democrat, had written to Samson and Port Authority Vice Chairman Scott Rechler in December, expressing concern over the closures and enclosing a list of questions about the incident, the purported study and agency procedures.

He also inquired about Baroni’s sworn testimony before the Assembly Transportation Committee in November that the lanes were closed for a traffic study, asking what was the basis for the testimony, who on the board reviewed or approved it and when did the board learn that “most of the Authority had no knowledge of a traffic study.”

The Jan. 15 response, from board secretary Karen Eastman, described the closures as “aberrational” and said Wildstein directed them and provided the traffic study rationale and no one had reviewed or approved Baroni’s testimony.

The 15-member Assembly committee, appointed on Wednesday, is chaired by Assemblyman John Wisniewski, D-Middlesex.

Its counterpart, the Senate Select Committee on Investigation, was formed on Thursday, has seven members and is chaired by Sen. Loretta Weinberg, D-Bergen, whose district includes Fort Lee, where the traffic jams occurred.

The Senate committee also plans to issue subpoenas and appoint special counsel.

Neither Christie nor Samson, a former New Jersey attorney general, responded to a request for comment.¢