The Federal Bureau of Investigation conducted an inquiry code-named KINDRED SPIRIT, which it inherited from the original review of the Chinese acquisition of the W.88 nuclear warhead technology. Two of the three best suspects on a list of 70 people at Los Alamos National Laboratory known to have traveled to the People’s Republic of China (PRC) between 1984 and 1988 were the Taiwanese-born Wen Ho Lee and his wife, Sylvia Lee, who worked at Los Alamos as a data entry clerk with a Top Secret clearance.
The KINDRED SPIRIT investigation failed to gather enough evidence to mount a prosecution, but it did lead the mole hunters to Wen Ho Lee, who had been recorded in December 1982 holding a telephone conversation with the suspect in which he had suggested he could find out “who had squealed” on the scientist. Although he had initially denied the conversation, Lee admitted it when confronted with the evidence and then acted as an agent for the FBI, attempting to entrap the suspect in telephone calls and a personal meeting in California in which he wore a wire. The embarrassment for the FBI in May 1996, after an inquiry lasting eight months and the pursuit of 12 possible leads, was that their own informant, Wen Ho Lee, had been
identified as the “only individual with the opportunity, motivation and legitimate access to both W.88 weapons systems information” known to have been betrayed to China.
Lee was interviewed formally by the FBI in January 1999 and again in March and was finally arrested in December 1999 and kept in solitary confinement, supposedly to prevent him from compromising any further information. Actually, the FBI hoped that, in jail without bail, the scientist would crack and confess, but after 227 days of imprisonment, he was released in September 2000 after a plea bargain: the prosecution would drop 58 of the 59 charges in return for information on the whereabouts of the crucial missing seven tapes.
With the promise of immunity, Lee admitted there had been more like 17 or 20 tapes, but insisted he had discarded them in a trash dump. None were ever recovered and Lee was convicted of a single felony and sentenced to the time he had already served.
A counterintelligence assessment of Lee made a convincing argument for him having been recruited by Li De Yuan at a conference held at Hilton Head, South Carolina, in 1985, and this had heralded his first known trip to Beijing the following year, to address the Tenth International Conference on Fluid Dynamics. The FBI had briefed Lee before his attendance and had also approved a second trip, in 1988, when he had met senior explosives expert (and future chief of the PRC’s entire nuclear weapons program) Hu Side and the director of the Institute of Applied Physics and Computational Mathematics, Zheng Shao Tang, in his hotel bedroom. Upon his return from each trip, he had listed the names of the scientists he had met, but had denied having been asked about any classified information. Years later he would admit that he had helped the Chinese with hydrodynamic nuclear codes on both occasions. A third invitation, to both Wen Ho and Sylvia in early 1989, to attend a conference on experimental fluid mechanics at Chengu, was declined on instructions of the increasingly anxious head of security at Los Alamos, and although they could travel to the PRC no more, there were no restrictions placed on trips to the Republic of China and Hong Kong, which they visited in March and December 1998 and again in 1992.