Kim Sung-woo murdered his mother-in-law and kidnapped his wife; was there really no way to stop him?
On the November 7 broadcast of SBS's "Unanswered Questions," the investigative program tracked the Songpa mother-in-law murder and spouse abduction case.
In the early morning hours of October 11, in a residential neighborhood in Songpa District, Seoul, one woman was murdered and another woman was kidnapped.
An assailant ambushed Min-ji as she was returning home from work, stabbed Min-ji's mother multiple times with a weapon as she attempted to intervene, and subsequently abducted Min-ji before vanishing. The assailant turned out to be none other than Min-ji's husband, Kim Sung-woo.
He fled after killing his mother-in-law and kidnapping his wife. In a mountainous area in Yangyang, Gangwon Province, Min-ji managed to escape seven hours after the incident began, and Kim Sung-woo was apprehended two hours later.
Min-ji blamed herself, feeling that everything was her fault. However, it came to light that the bereaved family had never even met Kim Sung-woo and did not know that Min-ji was married.
In reality, it was revealed that Min-ji had registered their marriage under coercion from Kim Sung-woo. Seven months into the marriage, she sought to end their relationship through an annulment lawsuit and went into hiding to get away from Kim Sung-woo.
Yet on the day of the crime, Kim Sung-woo had planned his actions knowing Min-ji's exact off-work time. Kim Sung-woo had told Min-ji, "I paid 20 million won to a private detective agency to find your location. I wanted to kill your entire family. I wanted to sell your younger sibling to China."
It was revealed that Kim Sung-woo had indeed hired private detective agencies on multiple occasions to pinpoint Min-ji's whereabouts. While the agency that took the job stated they were unable to locate Min-ji, Kim Sung-woo received various tips in the process and ultimately staked out on his own to uncover her location.
Although he was affectionate at first, Kim Sung-woo gradually began displaying violent tendencies. After Min-ji told him she wanted to end their relationship, he hid near the stairs in front of her home, ambushed her, bound her hands and feet with tape, and assaulted her multiple times. He then sexually assaulted her and even filmed her illegally.
In addition, he took out loans worth tens of millions of won under Min-ji's name and forced her to work as a hostess at a karaoke bar in Gangnam to bring in money. Min-ji handed over everything she earned directly to Kim Sung-woo.
With the help of a woman she met as a customer, Min-ji reported Kim Sung-woo for domestic violence, leading to emergency temporary measures being issued against him on August 22. That same day, Min-ji informed her family of her marriage and went into hiding in the provinces.
Frequently controlling Min-ji while suspecting her of infidelity, Kim Sung-woo purchased a weapon and rented a vehicle before the crime. He then staked out near Min-ji's family home almost daily, studying her daily routine and travel routes.
Kim Sung-woo stalked Min-ji 18 times during the emergency measures period and relentlessly tracked her for 50 days. Having begun his alternative service as a social service agent in 2022, he has been serving his mandatory military duty into his fifth year due to poor work conduct and frequent unauthorized departures from his duty station.
During this period, he also worked at an adult entertainment venue, where it was revealed he had a girlfriend who worked at the establishment at the time. An incident also took place where he blamed someone else entirely for his breakup with that girlfriend and carried out an assault.
Regarding this, an expert pointed out, "There is a category of people who use physical force to obtain what they want. What matters is whether someone exercises restraint when malice is provoked, but this individual is the type who fails to exercise control the moment a critical reason to do so arises."
Addressing Kim Sung-woo's attempts to control everything while having forced Min-ji to work at an adult entertainment venue himself, an expert analyzed, "Most people would give up one of the two, but he has no intention of giving up either. That is why he becomes angry, and he shifts the blame for that anger back onto the woman."
The expert added, "By our standards, he is an endlessly foolish person, but these are actions that make sense within his own logic. Having accumulated experiences where using violence allowed him to successfully control others, he developed a sense of 'this works' and 'I have completely subdued the other person'—a kind of winner effect—leading him to believe problems could be solved through assault, threats, and abduction. An ordinary person would not expect someone to still like them after doing such things. An extremely infantile and immature attitude is also a consistent trait demonstrated throughout this case."
Kim Sung-woo claims his actions were accidental. In response, an expert pointed out, "His objective was to kidnap Min-ji and restore their former relationship. However, if anything got in the way of achieving his goal, he was prepared to kill whoever it was—if that had not also been part of his plan, he would not have been able to act so swiftly in that situation."
The expert further analyzed, "He purchased a weapon weeks in advance and conducted stakeouts multiple times. This can be viewed as demonstrating extremely calculated, predatory aggression."
Experts noted that because the Domestic Violence Punishment Act lacks a monitoring system once temporary measures are ordered, authorities remained unaware even though Kim Sung-woo staked out for two weeks to track down his wife's location, stating, "Attaching electronic location-tracking devices to domestic violence offenders would serve as an effective measure."
Kim Sung-woo was classified under Grade A, the highest domestic violence risk level, yet police failed to extend the restraining order before it expired, culminating in tragedy. In response, the police offered only a written reply stating, "The restraining order was not extended because no circumstances were detected indicating that the perpetrator was attempting to approach the victim."
As of 2025, 137 women were murdered by men in intimate relationships. Consequently, discussions have emerged in certain quarters regarding legislative revisions aimed at increasing the maximum distance permitted under restraining orders and broadening the scope of protection so that everyone within a victim's personal network is shielded alongside the primary victim.
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