Dr. Lee, 55, is a chemist who told me of his important "achievements" in serving the North Korean regime since the 1970s. He worked with one team that produced bogus Japanese diplomatic passports used by agents to smuggle aboard the bomb that brought down Korean Airlines Flight 001. He helped produce counterfeit $100 bills used by diplomats traveling abroad.

It took an hour into our debriefing for Dr. Lee to get around to the fact that he helped develop deadly agents at a secret underground poison and toxin research institute. In that connection, he matter-of-factly described how, in 1979, he was in charge of gassing two political prisoners. The victims' suffering was documented by scientists, who took notes outside glass-encased gas chambers that were also wired for sound. One prisoner died after 2 1/2 hours, the other after 3 1/2 hours of agony. Then a young scientist, Dr. Lee was rewarded with a medal and promotions for his role in these successful experiments. Twenty-five years later, he expressed no remorse, but his recall of details and dates make him a credible, if frightening, witness.

Another North Korean defector I interviewed was 31-year-old Chun Ji Suang (also a pseudonym). In 1994, while attending a prestigious scientific institute, he was selected to be part of two teams researching various types of gassing -- from slow-acting, untraceable poisons to be used for assassinations to those that would cause instantaneous death. For eight years these scientists constantly moved their base of operations throughout the North Korean gulag. He belonged to Team A, which experimented exclusively on animals. When they successfully concluded an experiment, Team B then used those results on human guinea pigs. Unlike Dr. Lee, this young man is very remorseful. His escape from North Korea was facilitated by a supervisor and other secret sympathizers who urged him to expose Kim Jong Il's atrocities.