Officials said that it took a couple of days for the South's Navy to seize the North Koreans as they attempted to run away after crossing into the South. It said a South Korean investigation later found the two had killed 16 colleagues, including the captain.
The two North Koreans, both men in their 20s, were found aboard a boat south of the eastern sea border last Saturday, according to Seoul's Unification Ministry.
Kwon was a part of the North Korean delegation on the current working-level nuclear talks with the United States in Sweden, when Pyongyang walked away blaming Washington's lack of "new and creative" options.
"They can not be treated as refugees under global laws", ministry spokesman Lee Sang-min said. Neither can they be regarded as refugees under worldwide law because they are vicious criminals. They attempted to flee when the South's Navy tried to capture them, officials said.
Unification Minister Kim Yeon-chul told the National Assembly on Thursday that the two deported men and another fellow sailor were involved in killing 16 fellow sailors, including the skipper of their fishing boat.
How badly was Trump booed at UFC fight at Madison Square Garden?
Jorge Masvidal , who won the headline fight against Nate Diaz , was asked his opinion of the President in the run-up to the event. Trump himself saw a mixed reaction from MMA fans at Madison Square Garden , with both cheers and boos audible in the crowd .
The Coast Guard rescued 60 North Koreans but there was no way to confirm they had been illegally fishing within Japan's exclusive economic zone (EEZ) - as their boat had sunk.
While fishing in waters near Russian Federation and elsewhere, the two men collaborated with another crew member and killed the captain, who they said had abused them. -South Korean military drills would amount to "throwing a wet blanket over the spark" of nuclear negotiations between Pyongyang and Washington.
The trio later killed the 15 other fishermen one by one and threw their bodies overboard.
Aside from the accusations of murder, the case is unusual in that it is the first time Seoul has returned any North Koreans trying to flee the nation since the Korean War, which ended in 1953, according to the Associated Press.
Observers say the men are likely to receive heavy punishment in North Korea, including possible execution.
About 32,000 North Koreans have fled to the South since the end of the Korean War, a lot of them via China and in the past two decades.