'Unanswered Questions' investigates the truth behind the unsolved serial murder case that occurred 20 years ago in Sinjeong-dong, Seoul. SBS's current affairs program 'Unanswered Questions' episode 1468, titled "B2, Saw the Monster - The Truth of the 2005 Sinjeong-dong Serial Murder Case," delves into the reality of the case.

The Sinjeong-dong serial murder case began on June 7, 2005, in a residential area of Sinjeong-dong, Seoul. At that time, the body of a woman in her 20s, identified as Kwon, was found inside an abandoned rice sack. Kwon had gone out on Memorial Day and lost contact afterward. Her body was strangled, covered with the rice sack, and tied with a rope when abandoned. Although sexual crime was suspected, no DNA of the perpetrator was detected at the scene. The investigation struggled without finding any clues.

About six months later, on November 21, another body was discovered in a parking lot in the Sinjeong-dong residential area. The body of a woman in her 40s, identified as Lee, was wrapped multiple times in a mat and large plastic bags. Lee was last seen on CCTV returning home before disappearing. The two cases showed similarities in various circumstances. Both victims disappeared around the Sinjeong Station area on holiday afternoons and were strangled and abandoned in wrapped conditions. Suspicion arose that the same perpetrator was responsible, but without decisive evidence, the cases remained long-term unsolved.

A turning point came in 2020. Upon re-examining the victims' belongings, identical DNA was confirmed in both cases. Detective Kim Jang-soo of the Seoul Metropolitan Police Agency's Mobile Investigation Team 4 stated, "Out of 231,897 suspects, we compared DNA with 1,514 living individuals. It took more than four years." After an extensive comparison process, the outline of the perpetrator emerged 20 years after the crimes.

The serial killer was identified as Jang, a man in his 60s who worked as a building manager at the Y Building in Sinjeong-dong at the time. He had already been deceased for 10 years, making direct interrogation impossible. Questions remain about how Jang could have committed crimes against two different women in separate locations and how he evaded the investigation for nearly 20 years.

A crucial clue to reconstructing the case came from an unexpected tip. A woman using the pseudonym Choi Eun-jin called the production team and testified that in February 2006, she narrowly escaped being kidnapped by Jang. "He tried to grab me and drag me into the basement, and I still have a scar from being stabbed in the navel area," Choi revealed. She recounted desperately fleeing from the underground space where she was alone with Jang.

Choi's testimony provided important details about Jang's method and the location of his crimes. Questions arise about the nature of the basement she identified and what crimes Jang prepared there. Further investigation is needed to determine whether there were any additional unconfirmed offenses.

The full story of the Sinjeong-dong serial murder case, which remained unsolved for 20 years, can be found in 'Unanswered Questions.' This case vividly illustrates the complexity of criminal investigations and the challenges of solving cold cases. The program highlights the course of the case and the victims' stories, prompting society to reflect on the vigilance needed against such crimes.