David Petraeus: FBI's 'Agent Shirtless' unmasked as Frederick Humphries II According to The Times, Mr Humphries' involvement in the Petraeus scandal was only the most recent dramatic episode in the colourful career of the "hard-charging" field agent. Humphries at a crime scene in Tampa, Florida, in 2007. Picture: REUTERS/Thomas M. Goethe/Tampa Bay Times/Files Mr Humphries joined the FBI in 1996. He first came to prominence in 1999 after an Algerian man was arrested by US Customs agents as he tried to enter Washington state from Canada by ferry. Ahmed Ressam, who is also known as the Millennium Bomber, had white powder, chemicals and homemade timing devices in the trunk of his car. Ressam claimed to be a French-speaker from Quebec. According to a 2002 Seattle Times story, Mr Humphries, then the only French-speaker assigned to the FBI's Seattle office, was asked to question him. As soon as Mr Humphries heard Ressam's accent and phrasing, he knew he wasn't from Quebec and told his colleagues to arrest him, the story said. It was later learned Ressam, who is in jail for terrorism-related offences, was part of an al-Qaeda plot to blow up the Los Angeles airport on New Year's Eve 1999. Two years ago, reports claim that Mr Humphries shot and killed a man who attacked him with a knife outside MacDill Air Force Base in Tampa. The Associated Press reported that 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 Mr Humphries as he tried to exit a gate. The officials claimed Bullock got off the motorcycle and came at Mr Humphries and the officers while brandishing a knife. Mr Humphries fired, killing Bullock. The shooting was judged to have been an appropriate use of force. He's kind of an obsessive type. If he locked his teeth onto something, he'd be a bulldog," one former colleague told the New York Times. Lawrence Berger, a lawyer for a federal agents union representing Mr Humphries, said that the shirtless pictures had been "a joke" sent long before the Petraeus investigation. "That picture was sent years before Mrs Kelley contacted him about this, and it was sent as part of a larger context of what I would call social relations in which the families would exchange numerous photos of each other," Mr Berger told the New York Times. He refused to discuss allegations that his client had leaked details of the investigation to Eric Cantor, the second most senior Republican in the House of Representatives. "He's committed no misconduct," Mr Berger said. The FBI is reviewing Mr Humphries' later conduct in this case, a federal law enforcement official told the Associated Press on Wednesday. Specifically, the bureau is reviewing a telephone call he made in late October to Republican Rep Dave Reichert, to voice concerns that the bureau was not aggressively pursuing a possible national security breach. Mr Reichert arranged to convey the information to House Majority Leader Eric Cantor, who checked with the FBI at that time. Mr Cantor was assured the bureau was on top of any possible vulnerability.