(Carmen Natale)

Gibson, Dunn & Crutcher, the firm N.J. Gov. Chris Christie tasked with investigating his administration’s possible complicity in the Bridgegate scandal, issued a 360-page report Thursday that cleared the governor’s office and laid blame squarely on a former aide and a Port Authority staffer.

At a press conference at the firm’s New York offices, partner Randy Mastro said Christie had “no knowledge beforehand” of the plan to close access lanes to the George Washington Bridge in Fort Lee last September and “played no role whatsoever” in executing that plan.

The plan was hatched by Port Authority staffer David Wildstein and carried out with the help of the governor’s deputy chief of staff, Bridget Kelly, Mastro said. He called the ulterior motive unclear but said the scheme was a product of “bizarre personal or political animus” against Fort Lee by Wildstein.

Other key figures, former Port Authority Deputy Executive Director Bill Baroni and former Christie campaign manager Bill Stepien, came out relatively unscathed. The report found they knew in advance about the lane closures but apparently believed them to be related to a legitimate traffic study.

Mastro deflected suggestions that he might have been biased in his investigation because of his former close relationship with New York Mayor Rudy Giuliani, a Christie ally.

“It serves no one’s best interest…certainly not mine or my law firm’s interest…to have done anything other than to try to get to the truth here,” Mastro said, referring to himself as a “proud Democrat” and “fiercely independent.”

“Our law firm was retained by the Office of the Governor…a public office, and we have an obligation to that public office,” Mastro added, claiming he’d be obligated to report any evidence averse to Christie, whom he met for the first time when the firm was retained.

The 10-week probe, conducted by Mastro and four other former federal prosecutors at Gibson Dunn— Reed Brodsky, Alexander H. Southwell, Debra Wong Yang and Avi Weitzman—included interviews of 70 people, including the governor.

Not interviewed were Wildstein, Kelly, Stepien or David Samson, Port Authority chairman and partner at Wolff & Samson in West Orange. The first three have invoked their Fifth Amendment privilege against self-incrimination. Samson declined to be interviewed, Mastro said.

Speculation that the closures were ordered as political retribution against Fort Lee Mayor Mark Sokolich, a Democrat who declined to endorse Christie in the November 2013 gubernatorial race, was not borne out by the evidence, the report said. It found Christie’s office was aware beginning in March 2013 that no endorsement would be forthcoming, but Sokolich maintained a good relationship with the administration and remained under Christie’s consideration for an honorary appointment.

The firm said Wildstein apparently had a vendetta against Fort Lee—possibly stemming from perceived special treatment because of its local access to the bridge—and raised that issue as far back as 2010. In August 2013, Wildstein began communicating with Kelly about the proposed closures, which he ultimately ordered—without notice to Fort Lee and despite internal Port Authoity emails warning they would yield a traffic nightmare, according to the report.

During the closures and afterwards, Kelly and Wildstein continued to communicate in messages that have become well-known since their public exposure in January, including Kelly’s response of “Good” when told that Sokolich was fuming over the traffic, the report stated.

The firm found that they also attempted to cover their tracks—Wildstein, by insisting to Christie staffers that a legitimate traffic study was conducted, with Kelly’s and others’ knowledge, and ultimately resigning in December; and Kelly, by lying about her involvement and attempting to have at least one damning email message deleted.

The firm said Christie, for his part, demanded answers about the lane-closure debacle from his entire staff, including Kelly, who didn’t step forward and also lied about her involvement under questioning by Chief of Staff Kevin O’Dowd. Christie fired her and cut ties with Stepien after the communiques became public on Jan. 8.

Christie also didn’t recall a supposed conversation with Wildstein about the lane closures during a 9/11 memorial event, according to the report.

The report also addressed Hoboken Mayor Dawn Zimmer’s allegations of a Christie administration conspiracy to coerce her into advancing a stalled real estate project pursued by the Rockefeller Group, a private developer, in exchange for Hurricane Sandy aid. Zimmer claimed that high-ranking officials, including Lieut. Gov. Kimberly Guadagno, conveyed the quid pro quo as a “direct message” from Christie.

The firm said Zimmer’s allegations are demonstrably false in material respects and contradicted by other accounts, including her own prior statements. On Jan. 11, a week before first making her allegations, she told the press that, while disappointed with Hoboken’s Sandy aid, “I don’t think it was retaliation and I don’t have any reason to think it’s retaliation,” the report noted.

The firm discredited the handwritten notebook that Zimmer offered as corroboration for her account, noting that it was, by her own admission, written a few days after the events it purported to chronicle and that “its most inflammatory statements appear to have been added even later, written across the top and down the side of pages.”

The firm said its investigation found that the conspiracy alleged by Zimmer could not have been effectuated, in view of the Christie administration’s “objective and transparent” and formula-driven process for allocating Sandy aid, which is subject to federal oversight. “In other words, the threats that Mayor Zimmer has alleged were neither carried out, nor could they have been,” the firm concluded.

The report also made numerous recommended changes, including appointments of a chief ethics officer and an ombudsman in the governor’s office, and commission of a bi-state study of the Port Authority.

Stepien’s lawyer, Kevin Marino of Marino, Tortorella & Boyle in Chatham, says the report “confirms” his client’s lack of involvement in the stunt.

“I’m left with a single question: why did the governor sever ties with Bill Stepien?” Marino said, adding that Christie and his advisors “ought to have the courage to step forward now…and say ‘we made a mistake.’”

Wildstein’s lawyer, Alan Zegas of Chatham, didn’t return a call.

Neither did Baroni or Kelly’s lawyer, Michael Critchley of Critchley, Kinum & Vazquez in Roseland.

Christie’s office, in a release, highlighted parts of the report, but spokesman Michael Drewniak didn’t respond to an email seeking comment.

Contact the reporter at dgialanella@alm.com.