Kang Ho-sun was born on October 10, 1969, in South Korea. Very little about his childhood and early family background has been widely reported, but media sources note that he grew up with a quiet and reserved demeanor. Outwardly, Kang lived an ordinary life in Ansan, Gyeonggi Province, a suburb just outside Seoul.

He married in the early 2000s, but his marriage ended in tragedy. On October 30, 2005, Kang’s wife and her mother were killed in what initially appeared to be an accident but was later revealed to be Kang’s first murder.

Kang Ho-sun committed a series of murders in Ansan, Gyeonggi Province, from 2005 to 2008. His first victims were his wife and her mother, killed on October 30, 2005. He then killed Yoon Jung-hyun, a 23-year-old, on September 7, 2006.

Kang's violence continued into December 2006, when he murdered Bae Kyung-mi, a 45-year-old karaoke bar employee, and Park Sung-ah, a 37-year-old karaoke bar employee, in Suwon. In January 2007, he killed Park Jung-ja, a 52-year-old office worker, and Kim Hae-young, a 37-year-old karaoke bar employee. He also murdered Yeon Mi-young, a 21-year-old university student from Suwon, on January 7, 2007.

Later, in November 2008, he killed Kim Soo-hee, a 48-year-old housewife. His final confirmed victim was Ahn Young-ok, a 19-year-old university student in Ansan, on December 19, 2008.

Kang was arrested on January 27, 2009. After two days of investigation, he confessed to all 10 murders. Investigators discovered more remains of his victims, identified through DNA evidence. The families of the victims later sued Kang for damages.

On April 22, 2009, Kang was sentenced to death for his crimes. Although he received the death penalty, South Korea has had an informal moratorium on executions since 1997. In prison, Kang did not show remorse for his actions. He behaved dominantly towards other inmates until a fellow inmate's suicide made him realize the gravity of his situation.