In the quiet motels of Seoul's Gangbuk district, a 20-year-old woman named Kim So-young met men she had connected with online or through dating, often suggesting they go somewhere private to eat delivered food or relax.
What began as seemingly casual encounters in late 2025 turned deadly.
Between mid-December 2025 and February 9, 2026, Kim is accused of handing three men drinks laced with benzodiazepines, powerful sedatives she had obtained through psychiatric treatment.
Two of those men died from drug intoxication, their bodies discovered hours later in the rooms, one with secretions coming from his nose and mouth, stiff on the bed. A third survived but slipped into a two-day coma.
Police later identified at least three more victims who lost consciousness after consuming similar spiked drinks in restaurants, motels, or karaoke bars, bringing the total alleged harmed to six.
This tragedy unfolded against the backdrop of South Korea's drinking culture, where alcohol beverages flows as a social lubricant in a society that values group harmony, hierarchy, and after-work bonding.
Specifically, the consumption of soju, the clear, rice-based spirit is normalized, is popular among young individuals in their twenties seeking casual companionship. This night activity is so popular that convenient stores sell drinks just to beat hangovers.
While alcohol helps people socialize, and that sharing drinks builds trust and intimacy in fleeting encounters, it also creates vulnerability.
Mixing alcohol with sedatives like benzodiazepines heightens dangers dramatically, as the combination can swiftly lead to respiratory failure.
This is exactly what Kim did to her victims.
She crushed her prescribed pills, including Lunapam and Samjin Diazepam, using the butt of a kitchen knife and mixed the powder into beverages she presented as hangover cures or energy drinks. In one case, after a man collapsed in a café parking lot area, she claimed it was just to help him sleep.
After the first non-fatal incident in December, where the survivor filed a complaint and tested positive for benzodiazepines, Kim escalated.
The first fatal case struck on January 28 or 29.
Kim met a man in his twenties, reportedly named Kim Soo-hyuk in some accounts using an alias, after connecting days earlier. They checked into a motel in Suyu-dong, Gangbuk-gu. CCTV and dashcam footage captured them entering together.
About two hours later, Kim left the room alone.
The next day, motel staff who realized that the room wasn't checked out, went in to only discover a man dead on the bed.
His body had stiffened in rigor mortis, with secretions visibly coming from his nose and mouth, a common sign of respiratory depression and overdose from the powerful sedative-alcohol mix. Autopsy by the National Forensic Service confirmed acute drug intoxication, with benzodiazepines matching those prescribed to Kim detected in his system.
Before authorities could fully connect the dots, Kim allegedly struck again on February 9.
She entered another motel in the same Gangbuk area with a different man in his twenties. After he consumed the spiked drink, he collapsed. Kim reportedly used his phone and card to order a massive delivery of fried chicken, 22 items worth around 130,000 won.
She left the room carrying the bags, and similar to the previous case, she abandoned the man unconscious or dying inside.
The man was found dead the following day.
Toxicology again pointed to acute drug intoxication from the benzodiazepine-alcohol combination, his body showing the devastating effects of suppressed breathing and cardiac strain. Prosecutors described both acts as planned.
After the police pointed out Kim as the perpetrator, they seized her device and found that she consulted OpenAI;s ChatGPT before her acts.
Days before one of the fatal incidents, she asked the AI chatbot questions such as, "What happens if you take a lot of sleeping pills?" and "What happens if you take sleeping pills and alcohol together?"
ChatGPT warned of high risks including respiratory paralysis and death.
She followed up with, "How much is dangerous if you take them together?" and "Could you die?"
On the day of a murder, she reportedly asked again about lethality. Police say she then doubled or more than doubled the dosage for subsequent victims, adjusting based on what she learned.
Investigators also found that Kim allegedly used her social media accounts, particularly her Instagram account, to prey on her victims. She frequently posted selfies, and that she responded to some of the men who commented, in attempt to bait them.
It's worth noting that at least one of the men she went out with, was unharmed because he didn't drink alcohol.
Kim allegedly targeted only men who drank alcohol.
If she realized that the man she went out with would not drink, she would abandon the drugging plan and simply ask him for money instead. In one such instance, when a man refused to drink, Kim bought about a dozen commercial hangover cure drinks with the man's money, presumably to use as a vehicle for the powdered sedatives on her next victims who were more willing to consume alcohol.
Kim has consistently denied any intent to kill, insisting she only wanted to make the men fall asleep out of fear of unwanted sexual contact or assault.
Her claims tap into deep-seated anxieties many South Korean women harbor amid widespread concerns over dating violence and intimate partner abuse. Surveys show nearly one in five Korean women has experienced some form of violence from a current or former partner, including physical, sexual, or emotional harm, with rates rising particularly among those in their twenties.
In a patriarchal society where traditional gender roles linger despite rapid modernization, women often navigate dating with caution, fearing escalation in private settings like motels where help may not arrive quickly.
Kim claimed the deaths shocked her and that she did not realize the antidepressants and sedatives she took herself could prove fatal when mixed with alcohol. In court and prison letters, she expressed regret, mentioning past traumas including alleged sexual assault and family issues.
Her defense highlights a low IQ assessed between 70 and 80, just above the threshold for intellectual disability, arguing this made meticulous planning unlikely and that she could not fully foresee the lethal outcomes.
A criminal psychologist noted the challenges this poses for proving deliberate murder under Korean law. Yet prosecutors point to the repeated ChatGPT queries as evidence she understood the dangers and proceeded anyway, along with the dosage increases and her actions afterward, such as ordering food and leaving victims behind.
The trial at Seoul Northern District Court has drawn intense public attention, with overflowing courtrooms and widespread media coverage.
Kim's identity was publicly disclosed after victims' families petitioned, and her mugshot and details appeared online, sparking both outrage and some unusual online interest in her appearance. A psychopathy checklist score of 25 out of 40 placed her above the threshold in Korea, with descriptions of lacking empathy and emotional control.
Releasing Kim's identity was actually a serious step, not undertaken without deep deliberation.
The process kicked off on March 3, 2026, when a dedicated identity disclosure review committee, made up of two internal experts and six external specialists, convened to evaluate whether Kim's actions satisfied the rigorous thresholds for publicly naming a suspect.
Under South Korea's Serious Crimes Information Disclosure Act, authorities can only reveal such details if the offense is especially vicious, results in major harm, strong evidence links the suspect to the crime, or compelling reasons of public safety and crime prevention clearly outweigh the usual protections around identity.
Victims' families have demanded the death penalty and filed civil suits for damages, including one for 31 million won.
Additional victims from late 2025 and early 2026 emerged during the investigation, some confirmed via hair samples showing benzodiazepines.
Prosecutors charged her with murder, aggravated injury, and violations of the Narcotics Control Act, describing the acts as planned and driven by an abnormal motive.
South Korea maintains the death penalty in law for serious crimes like murder, though executions have been on hold for decades in practice, creating a de facto moratorium.
Public opinion strongly favors capital punishment for heinous acts, with polls consistently showing seventy to eighty percent support, driven by demands for retribution in high-profile cases involving violence.
This reflects broader cultural attitudes toward crime, where shocking offenses prompt calls for harsh justice to restore social order, even as the justice system grapples with proving intent in complex scenarios involving mental health or cognitive factors.
The case stands out not just for the tragic deaths but as one of the first in South Korea, and among the earliest globally, where ChatGPT conversation logs have been forensically extracted and used as direct evidence of intent in a murder prosecution.
Lawyers note that the conversational nature of AI allowed detailed, non-judgmental responses that a human might have flagged ethically, turning the chatbot into what one described as a personal assistant for the crimes without raising alarms.
It has also fueled broader debates about AI safety.
Kim's case here reveals the darker intersections of technology, mental health struggles, personal fears rooted in gender dynamics, and criminal acts in a digital age shaped by heavy social drinking norms.
It's worth noting that the public revelation of Kim's identity quickly stirred controversy.
Even before the official announcement, online users had already begun circulating her full name, photos, and social media profiles. The leak triggered a sudden spike in her follower count and sparked widespread concerns over "private punishment" and doxxing.
In response, prosecutors, acting with Kim's explicit consent, locked her social media accounts to private settings, aiming to stem further leaks and protect her from escalating harassment.
