Transcript for Son of Kim Jong Nam is reportedly in hiding: Part 6

Reporter: Just a couple of months ago, surveillance cameras rolling in the heavily armed demilitarized zone captured video that stunned the world -- a lone north Korean soldier, risking his own life, in a dramatic attempt to defect. To the south. Watch as he speeds along a road, then loses control of his truck. Hopelessly stuck in a ditch, and with fellow north Korean troopers in hot pursuit, the only option, run. In a hail of bullets, the desperate soldier crosses to the other side. But he's badly shot, his life now in immediate danger. "20/20" has obtained video of the rescue mission and an interview with the surgeon who saved the defector's life. He was transferred here from dmz area right away. Reporter: He probably would have died if was not rescued instantly. Yes, that's right. Reporter: The doctor says the soldier's desperation is a clear sign that life is getting worse in North Korea under the rule of Kim Jong-un. My name is Kim han-sol, from North Korea, part of the Kim family. Reporter: But could this young man, the son of the murdered Kim jong-nam, be the face of hope for the north? Reporter: In this video released not long after his father's murder, he says he's safe. My father has been killed a few days ago. Reporter: But for how long? Intelligence sources tell us he's now the target of death squads, dispatched by his thless uncle, forced deep into hiding under Chinese government protection. Kim han-sol obviously is -- also poses a threat to Kim Jong-un, just by bloodline. So I really hope that he's in safe hands. Today, there are many Koreans hoping that the living legacy of Kim jong-nam might one day come home to claim his place as the head of the paektu family dynasty. We hope this gets better.

This transcript has been automatically generated and may not be 100% accurate.