The family of a South Korean man who was shot and killed by North Korean soldiers is planning to sue the DPRK government “just like the Warmbier family did,” the victim’s brother told NK News on Monday.

Lee Dae-jun, a 47-year-old Ministry of Ocean and Fisheries worker, was killed on Sept. 22 after mysteriously ending up in North Korean waters during a routine patrol trip on a boat. Now, his brother, Lee Rae-jin, is consulting a lawyer and vowing to “punish” Pyongyang for the slaying.