Death by experiment

North Korea | An extensive chemical testing program shows how far North Korea will go to achieve a WMD arsenal | Priya Abraham

In a café in Seoul, South Korea, Chun Ji Seung explained he was desperately sorry for what he had done. He was tall for a North Korean, a member of the well-fed elite that knew little of the starvation of millions in the closed nation. With that privilege, he applied his training in chemistry to test poisonous gases, gases the Kim Jong Il regime eventually tested on humans.

The 31-year-old Mr. Chun—whose name is an alias—said such experiments were conducted as recently as 2002, when he escaped to the South. Similar accounts have trickled out over the last decade, but his is the latest piece in a still-murky picture of testing related to developing weapons of mass destruction. His story emerged when Abraham Cooper, associate dean of the Simon Wiesenthal Center, traveled to Seoul last November and spent 10 hours interviewing three defectors who conducted such research at the behest of the Kim Jong Il regime.