Donald Sachtleben of Carmel, Ind., said in court papers that he provided details of the operation to a reporter. Four months ago, Sachtleben also acknowledged he distributed and possessed pornographic images of underage girls.
A plea agreement filed in U.S. District Court in Indianapolis calls for 11 years and eight months in prison for both crimes.
The Justice Department said in a statement that its pursuit of Sachtleben was made easier by the child pornography investigation, but that Sachtleben was not identified as a suspect in the leaks case until after investigators had analyzed the AP phone records and compared them to other evidence in their possession.
AP spokesman Paul Colford said, "We never comment on sources."
The deal is the latest legal action in the Obama administration's aggressive pursuit of people it believes have revealed government secrets, including seeking records and even testimony of journalists who prosecutors believe were given classified information and then published stories about it.
Monday's court filing stems from an investigation launched by the Justice Department shortly after AP reported that U.S. intelligence had learned that al-Qaida's Yemen branch hoped to launch a spectacular attack using a new, nearly undetectable bomb aboard a U.S.-bound airliner around the anniversary of Osama bin Laden's death. The AP's May 7, 2012, story attributed details of the operation, including that the FBI had the bomb in its possession, to unnamed government officials.
CIA Director John Brennan has called the leak "irresponsible and damaging," while Attorney General Eric Holder said the story was the result of "a very serious leak, a very grave leak."
Just over a year after the story appeared, on May 10, the Justice Department informed AP that it had secretly obtained nearly two months of call records for more than 20 telephone lines used by AP reporters and editors, including some who worked on the story.
The news cooperative protested the government's actions as chilling to investigative journalism and the company and its reporters did not cooperate in the investigation. AP chief executive Gary Pruitt called the records' seizure a "massive and unprecedented intrusion" into how news organizations gather the news.
The court records do not identify AP or name the reporter who communicated with Sachtleben. But the headline from the AP story that ran on May 7, 2012 is reproduced in the federal court records and Larry Mackey, Sachtleben's Indianapolis-based lawyer, said the AP is the news organization described in the papers.
Sachtleben spent 25 years as an FBI special agent bomb technician and worked on major cases involving terrorist attacks, the government said. He retired in 2008, but was rehired as an FBI contractor and kept his "top secret" security clearance and access to the FBI lab in Quantico, Va.
In court papers, Sachtleben said he visited the FBI lab on the morning of May 2, 2012, at the very time that FBI experts were examining the bomb. Sachtleben shared that information with a reporter the same morning, the government said.
The AP story ran five days later, on May 7, 2012. The news organization had initially agreed, for several days, to the Obama administration's requests to hold off on publishing it.
The child pornography investigation did not become public until May 11, when the FBI searched Sachtleben's home and seized a Sony laptop from his truck in the driveway. The FBI said it found 30 photos and videos of child pornography on the computer. Sachtleben was arrested the same day. The government said it began investigating Sachtleben for child pornography after an email address linked to him popped up on a known child-porn web site.
Sachtleben apologized in a brief, three-sentence statement that his attorneys released on his behalf Monday afternoon.
"I am deeply sorry for my actions," he said. "While I never intended harm to the United States or to any individuals, I do not make excuses for myself."
The Justice Department said it had already had in its possession, as part of the child pornography investigation, Sachtleben's cell phone, computer and other electronic media, including a CD/DVD containing classified information.
But the department said in a statement that it was able to link Sachtleben to the unauthorized disclosures about the Yemen plot only after investigators had analyzed the seized AP phone records and compared them to other evidence already in their possession.
Based on the analysis, they were able to get a search warrant for a new and more thorough look at his phone and computer, the department said.
Around the same time that the government told AP its phone records had been obtained secretly, court records were made public that showed that prosecutors had obtained a search warrant for the emails of Fox News reporter James Rosen. The government says Rosen received secret information about North Korea from State Department adviser Stephen Kim, who faces criminal charges over the alleged disclosure. Kim's case is among seven the administration has brought against people suspected of providing classified information, more than under all previous presidents combined.
In a speech on May 23, in the days following the disclosures of the government's actions in the two cases, President Barack Obama defended his administration's pursuit of leakers of government secrets. But he also said Congress should consider a law that generally would protect journalists from government subpoenas and allow judges, in rare instances, to decide whether national security concerns trump press freedoms. The Senate Judiciary Committee approved such a measure on Sept. 12 and a similar bill has been introduced in the House.
The president also directed Holder to review the Justice Department rules, first drafted in the wake of Watergate-era government abuses, that guide efforts to obtain reporters' records.
The department announced on July 12 that it would toughen its guidelines for subpoenaing reporters' phone records, and also raise the standard the government needs to meet before it can issue search warrants to gather reporters' email.
The changes included creation of a News Media Review Committee to advise top officials when the department seeks media-related records in investigations. Another change requires the government to give advance notice to the news media about subpoena requests for reporters' phone records unless the attorney general determines that "for compelling reasons," such notice would pose a clear and substantial threat to the integrity of the investigation.