A court in Seoul has sentenced a North Korean defector to four years in prison for trying to assassinate another defector with a poisoned needle.
The defector surnamed Ahn was arrested last year for trying to kill another who regularly sends anti-Pyongyang leaflets across the Korean border.
The Seoul Central District Court said that Ahn was convicted a day earlier.
South Korea's Yonhap news agency says North Korean agents ordered Ahn to kill the activist, and he agreed because he resented the south's intelligence agency.
The court said Ahn's plot was a threat to national security.
More than 21,000 North Koreans have defected to the South since the Korean War ended in 1953. Defectors undergo questioning to make sure they are not spies.