FBI agent in Petraeus scandal had helped stop a plot to bomb Los Angeles airport in 1999

TAMPA, Fla. (AP) -- FBI Special Agent Frederick Humphries II played a key role in investigating a terrorist attack aimed at blowing up Los Angeles International Airport just as the year 2000 dawned.

Today, the agent, who also fatally shot a knife-wielding man in 2010, finds himself in the middle of the scandal that has resulted in CIA Director David Petraeus' resignation.

Humphries, 47, was the agent who initially saw the emails the FBI said Petraeus' biographer and mistress, Paula Broadwell, sent to Tampa socialite Jill Kelley, a woman she apparently saw as a rival for Petraeus' affections. She also allegedly sent emails to Gen. John Allen, Kelley's friend and the top U.S. commander in Afghanistan.

Concerned about the emails, Kelley contacted Humphries in June. Kelley had attended a 2011 FBI Citizens Academy, a program aimed at teaching the public and journalists about the agency, and Humphries lectured one night about terrorism, according to Natalie Shepherd, a Tampa TV reporter who was there.

Humphries, a former Army captain who worked in military intelligence, thought the emails raised serious concerns because the anonymous author knew the comings and goings of Allen and Petraeus, a former general who had preceded Allen in Afghanistan. His report back to the FBI started the investigation that led to Broadwell and uncovered her affair with Petraeus.

Word of Humphries' concerns about the case reached Rep. Dave Reichert, R-Wash., who relayed them to Rep. Eric Cantor, R-Va., and arranged for Humphries to speak directly with Cantor about the case on Oct. 27, according to a federal law enforcement official who was not authorized to speak on the record about an ongoing case and therefore demanded anonymity.

Lawrence Berger, the general counsel for the Federal Law Enforcement Officers Association, said in an interview Wednesday that his client, Humphries, did nothing wrong and should not be disciplined. "He's committed no misconduct," Berger said and predicted he would be cleared of any misconduct.

A shirtless photograph of Humphries also helped land the agent in hot water. The Seattle Times reported that Humphries sent the photograph to Kelley and others, including one of the paper's reporters, in an email Sept. 9, 2010.

The subject line read: "Which one is Fred?" The photo showed "Humphries - bald, muscular and shirtless - standing between a pair of equally buff and bullet-ridden target dummies on a shooting range," the newspaper reported.

Humphries joined the FBI in 1996 and first came to prominence in 1999 during the investigation of an Algerian man who was arrested by U.S. Customs agents as he tried to enter Washington state from Canada by ferry. Ahmed Ressam had white powder, chemicals and homemade timing devices in the trunk of his car.

Ressam claimed to be a French-speaker from Quebec, and according to a 2002 Seattle Times story, Humphries, then the only French-speaker assigned to the FBI's Seattle office, was asked to question him. It was later learned Ressam was part of an al-Qaida plot to blow up the Los Angeles airport on New Year's Eve 1999.

By 2010, Humphries had been assigned to the FBI's Tampa office and was its liaison to MacDill, home to the military's Central Command.

On May 19, 2010, 61-year-old Army veteran Ronald J. Bullock, who was camping at the base, got into an altercation with base security.

Officials said Bullock sped off on a motorcycle, but was stopped by other security officers and Humphries as he tried to exit a gate. They said he got off the motorcycle and came at Humphries and the officers while brandishing a knife. Humphries fired, killing Bullock. The shooting was later ruled justified.

Ap.