NEWARK, N.J. - After a nearly 16-month investigation, federal prosecutors announced charges Friday against two former allies of Gov. Christie, alleging that they conspired to jam traffic at the George Washington Bridge to carry out a political vendetta against a mayor who did not endorse the governor for reelection in 2013.

The indictments against Bridget Anne Kelly, Christie's former deputy chief of staff, and Bill Baroni, a former official at the Port Authority of New York and New Jersey, were announced an hour after another former Port Authority official and associate of the governor's, David Wildstein, pleaded guilty in federal court here to conspiracy charges.

U.S. Attorney Paul Fishman said his office did not plan to bring additional charges in the scandal "based on the evidence that is currently available to us."

Kelly and Baroni are scheduled to be arraigned in federal court here at 11 a.m. Monday

Christie, a Republican considering a run for president, said the charges supported his position that he played no role in the lane closures, which prosecutors say were timed to coincide with the first day of school in September 2013 to maximize the impact of the resulting traffic.

The law firm hired by Christie - Gibson, Dunn & Crutcher L.L.P. - had backed his position in a 360-page report released in March 2014. Christie's office spent about $9 million last year on legal fees related to the scandal.

"Today's charges make clear that what I've said from day one is true, I had no knowledge or involvement in the planning or execution of this act," Christie said in a statement. He said he had acted as soon as he learned of "this unacceptable behavior" and had cooperated with investigators.

"Now, 15 months later, it is time to let the justice system do its job," Christie said.

But as Christie tried to move forward, the potential for more trouble emerged.

In her first public appearance since she was fired by Christie in January 2014, Kelly told reporters Friday that she was innocent and would "no longer allow the lies that have been said about me or my role in the George Washington Bridge issue to go unchallenged."

Reading a statement in her attorney's office building in Livingston, she said, "For the indictment to suggest that I was the only person in the governor's office who was aware of the George Washington Bridge issue is ludicrous."

Wildstein's lawyer, Alan Zegas, earlier told reporters that his client was "intimately involved" in the closures but "deeply regrets" what occurred. Wildstein is fully cooperating with prosecutors, Zegas said.

Zegas also repeated his claim that Christie knew about the closures earlier than he at first acknowledged. "Mr. Christie knew of the lane closures while they were occurring," Zegas said, adding that "evidence exists" to prove it.

Fishman declined to comment on that claim, or about any other individuals not discussed in the indictment.

He also would not comment on the status of other inquiries his office has undertaken, including an investigation into former Port Authority Chair David Samson. Documents show prosecutors have subpoenaed the agency for records relating to his votes on matters before the Port Authority board, possibly to determine whether Samson used his power to help his law firm's clients.

Prosecutors have also issued a subpoena to the Port Authority seeking Samson's travel records and his relationship with United Airlines, which reportedly initiated a route from Newark to South Carolina at the chairman's request. Samson used the twice-weekly flight for weekend stays at a nearby home, according to multiple reports.

The politically charged day began when Wildstein walked into a courtroom around 11 a.m. to formally plead guilty to two conspiracy charges.

Making his first public appearance since he asserted his Fifth Amendment right against self-incrimination at a legislative hearing on the day the bridge scandal erupted in January 2014, Wildstein wore a dark suit with a white shirt and blue-and-red striped tie. He appeared noticeably slimmer.

As Fishman observed the proceeding from the second row in a room packed with about 100 journalists and lawyers, Wildstein repeatedly responded "yes" as U.S. District Judge Susan D. Wigenton outlined the conspiracy charges.

Wildstein was released on $100,000 bail, ordered to surrender his passports, and told to avoid contact with potential victims and witnesses in the case.

Assemblyman John S. Wisniewski (D., Middlesex) and State Sen. Loretta Weinberg (D., Bergen), the cochairs of the legislative committee that held multiple hearings on the lane closures, watched from the jury box.

Weinberg told reporters she felt "relief" that "somebody stood up and took responsibility" for the lane closures, but added she was "sickened" by the plot.

Asked about Christie's political future, Wisniewski said it was "too early to make any pronouncements" about how the day's events could affect the governor's likely bid for the presidency.

Following Wildstein's guilty plea, Fishman held a news conference announcing the charges against Baroni and Kelly.

Each was charged with misusing property of an organization that receives federal benefits; committing wire fraud; and depriving the residents of Fort Lee of their civil rights by restricting their ability to travel without a legitimate government objective.

Prosecutors allege that when Kelly confirmed in August 2013 that Fort Lee Mayor Mark Sokolich would not endorse the governor, she, Wildstein, and Baroni decided to punish the mayor, a Democrat whom Christie's team had courted before Christie's landslide November 2013 reelection.

"Time for some traffic problems in Fort Lee," she wrote in an e-mail to Wildstein. "Got it," he replied. The lane closures took place from Sept. 9 to 13, 2013.

Kelly's e-mail was unearthed by Wisniewski's Assembly Transportation Committee and made public on Jan. 8, 2014. Much of the evidence presented in the indictment had been made public previously as a result of the legislative inquiry.

After Wildstein convinced Port Authority personnel to close the lanes under the guise of a traffic study, he, Baroni, and Kelly "purposely ignored" communications from Sokolich pleading for relief to "enhance the effectiveness of their scheme," the indictment alleges.

Then they promoted a "sham story," the indictment says, that the Port Authority closed the lanes as part of a traffic study.

They perpetuated the cover story in a number of ways, the indictment alleges, including when Baroni made false and misleading statements to the Assembly Transportation Committee in November 2013.

"Let me be clear, Wildstein has admitted and the indictment alleges that the traffic study story was a sham, a total fabrication that Baroni, Kelly, and Wildstein created and used to execute their scheme, and to cover up their misdeeds and their misuse of public resources," Fishman said.

The indictment says Wildstein first indicated an interest in closing the lanes in March 2011. Asked to elaborate on the early planning in 2011, Fishman declined to comment.

That timeline could cast doubt on the government's theory that the lanes were closed after Sokolich declined to endorse Christie.

Kelly and her lawyer, Michael Critchley, said the idea wasn't credible.

"As the governor's former spokesperson stated under oath, it is an absurd thought to believe that a member of the governor's staff could close the George Washington Bridge," Kelly said.

Since Christie fired her in January 2014, Kelly has been unable to find work, Critchley said. A single mother of four, Kelly may lose her home, Critchley said.

Kelly has created a website that accepts donations for her legal defense fund.

Baroni's attorneys said their client was innocent and had been duped by Wildstein, a friend for more than 10 years, into thinking the lane closures were part of a traffic study.

Baroni, the former deputy executive director of the Port Authority and a former Republican state senator, "has placed principle above politics" throughout his career of public service, attorney Michael Baldassare told reporters outside the courthouse in Newark.

"By contrast," he said, "no one disputes that David Wildstein is a criminal and a liar." Baldassare said Wildstein's story was a "desperate ploy" to avoid prison.

A political blogger who wrote under the pseudonym Wally Edge - a play on Walter Edge, a former New Jersey governor - Wildstein was plugged into New Jersey political circles. He was friends with Christie's former press secretary, Michael Drewniak, and had ties to Mike DuHaime, Christie's chief political strategist.

At the Port Authority, where he was tapped for a newly created position in 2010, Wildstein was Christie's "eyes and ears" within the bistate agency, according to a description in a 2012 Bergen Record story.

But Christie has sought to distance himself from Wildstein. Though the two grew up in Livingston, and graduated a year apart in high school, "David and I were not friends in high school. We were not even acquaintances in high school," Christie said at a January 2014 news conference. "We didn't travel in the same circles in high school. You know, I was the class president and athlete. I don't know what David was doing during that period of time, and then we reacquainted years later, in, I think, 2000."

Fishman said Friday that Wildstein could face 21 to 27 months of jail under federal sentencing guidelines, though the decision is up to the judge. Wildstein likely will not be sentenced until his cooperation with the government is complete.

If found guilty, Kelly and Baroni could face slightly more time than that, Fishman said.