A North Korean nuclear researcher who fled to China committed suicide after being captured and returned to North Korea, Radio Free Asia reports. The man, who led a research team at Pyongyang’s State Academy of Sciences, reportedly took a leave of absence this year and disappeared across the China border. He was later captured with a group of North Korean defectors in Shenyang city, China, on Nov. 4, and returned to North Korea on Nov. 17. He took poison within hours of being placed in solitary confinement. It is unclear how he was able to get access to the poison in the North Korea lockup.