The Washington Post has a detailed profile of FBI Agent James J. Smith, now charged with Katrina Leung in a sordid espionage case. If you haven't been following the case, here are the essential details:

In court documents, federal prosecutors allege that Smith and Leung, who were both arrested here this month, had been having an extramarital affair for almost as long as she had been providing the FBI intelligence on the Chinese government. Prosecutors are accusing Leung of being a double agent, supplying Smith with information at the same time she was giving the Chinese copies of classified FBI documents that he blithely left unguarded in her presence. Smith, 59, has been charged with gross negligence on the job and is free on $250,000 bond. Leung, 49, has been charged with illegally obtaining classified documents for the purpose of aiding a foreign power and is jailed; a federal magistrate last week refused to release her on bail. Prosecutors say Leung may have provided Chinese officials with confidential details on FBI personnel, a range of secret intelligence cases and spying tactics that agents and their informants use. Leung's attorneys have denied the charges, and say she has made "heroic contributions" to the United States.

Smith retired three years ago after a long career as a respected and dedicated agent. Ten years ago, court documents show that another FBI Agent, since identified as William Cleveland Jr., also was having an affair with Leung and told Smith he suspected Leung was a double agent. Smith did nothing about it and continued to give Leung information. Cleveland has since been stripped of his security clearance and resigned his counterintelligence post at Lawrence Livermore National Laboratory.

The New York Times Sunday has a lengthy article on FBI problems with informants, and reports the biggest problems may occur when the agent and informant get too close, sexually or financially.

Leung's family issued a statement today.

Ms. Leung's family, in its first public comments, said in a statement released today that she had spent two decades "doing what the F.B.I. wanted," putting herself in great personal danger. The family said she was now being targeted in part because she is a Chinese-American woman. "When Katrina can present the full story, you will know she has been abused and smeared by the F.B.I., she is a loyal and patriotic American and she is innocent of any crimes against America," the statement said.