Why some North Korean defectors return to one of the world's most repressive regimes

He risked his life fleeing from one of the world's most repressive regimes, traversing a militarized stretch protected by barbed wire fences. Then a year later, he went back -- the way he came.

More than one month since the man crossed the demilitarized zone from South to North Korea, much of his life in both countries remains a mystery -- as do his reasons for returning to the isolated nation ruled by Kim Jong Un.

South Korean media reported that the defector -- who hasn't been officially named, although fellow defectors say he was called Kim Woo-jeong in South Korea -- was a former gymnast who largely kept to himself. According to South Korean police, he was a construction worker in his 30s who earned money by doing manual labor.