Frederick Humphries, one of the key players in the tawdry unravelling of Petraeus's once-storied career, set the wheels in motion for the general's downfall after he agreed last spring to investigate anonymous emails sent to a friend in Tampa, socialite Jill Kelley.
That probe revealed Petraeus's affair with Paula Broadwell, who was behind the harassing emails to Kelley, a woman she viewed as a rival for the four-star general's affections.
Humphries, 47, a counterterrorism specialist at the FBI, was born in the Washington state community of Steilacoom but attended high school somewhere in Ontario. His mother and stepfather live in Illinois.
He reportedly learned French in the Canadian school system, a skill that helped him nab Ressam, who claimed to be a Montrealer in 1999 as he attempted to sneak across the Canada-U.S. border to blow up the Los Angeles airport in a thwarted millennium attack.
Ressam, an Algerian al-Qaida member who lived in Montreal, was apprehended with explosives in the trunk of his car on a Canadian ferry to the U.S. and claimed only to speak French. But while reading Ressam his rights in the language, Humphries immediately knew he was not Quebecois, detecting an Algerian accent instead.
He warned his superiors that Ressam — who insisted he was someone named Benni Antoine Noris — was lying.
Before long, investigators discovered Ressam was using false ID and had charged him with plotting what would have been a deadly attack on one of the busiest airports in the U.S. Ressam is now serving a 37-year sentence.
The Ressam case resulted in lingering perceptions in the United States that Canada has a porous border — fears that have resulted in beefed-up border security over the past decade.
Humphries reportedly also challenged FBI brass for its decision to turn Ressam over to agents from New York in the aftermath of the Sept. 11, 2001, attacks two years later.
The Seattle Times reported that Humphries warned their strong-arm interrogation tactics threatened to undo his hard work convincing Ressam to co-operate. Humphries had gleaned a wealth of intelligence from Ressam about al-Qaida operatives, including information that helped thwart Richard Reid, the would-be shoe-bomber.
True to his predictions, Ressam did, indeed, ultimately stop providing information on al-Qaida to investigators and even tried to recant some of what he'd already told them.
Humphries testified in defence of Ressam about his harsh post-9-11 treatment at the hands of fellow agents. That led to intense criticism within the FBI, but Humphries was adamant he'd done the right thing.
The judge who oversaw Ressam's trial in Los Angeles praised Humphries repeatedly for his dedication and integrity.
A Canadian reporter who covered those proceedings called Humphries "the perfect picture of moral rectitude."
Thirteen years later, and the media spotlight on Humphries isn't quite so friendly.
Like almost everyone else in the ongoing Petraeus soap opera, Humphries — described as a hard-working but aggressive agent — has been tainted by accusations of seamy behaviour and personal vendettas.
The married Humphries has denied sending Kelley shirtless photos of himself after the investigation into her email began. In fact, he told the Seattle Times this week, the photo was sent two years ago as part of an ongoing joke, and was a picture he'd also sent to other friends and even a friendly reporter at the newspaper.
The Seattle Times posted the photo on its website on Thursday. It shows a smiling, bare-chested Humphries posing with his arms around two bullet-ridden shooting range dummies that possess a similar buff physique.
"There was absolutely no romantic involvement or relationship whatsoever between Agent Humphries and Jill Kelley," his lawyer, Lawrence Berger, told ABC News.
Yet the married University of Tampa criminology graduate was removed from the Kelley investigation in the summer amid fears he was too personally involved.
Humphries, however, suspected a coverup aimed at protecting U.S. President Barack Obama ahead of the November election, and tipped off a Republican congressman. He also reportedly feared the emails showing up in Kelley's inbox presented a national security risk given they contained details about the comings and goings of two powerful generals.
Humphries has acknowledged tipping off Washington state congressman Dave Reichert, but didn't provide further details in his interview with the Seattle Times.
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