Episode 60:
Sex Offender Out for 6 Months: Killed 2 Students with Hammer & Knife

A man walks into a motel in Changwon and asks for a room. "Give me a room on the third floor." Inside, he opens the window and glances down at the street below — then heads out to a mart, buys alcohol and a weapon, and returns to forcefully drag two middle school girls into his room.

At 5 p.m. on December 3, 2015, a strange call comes into the police reporting center in Changwon. The dispatcher gets no response, is about to hang up as a prank — then hears a single, urgent voice: "Stop it!" The line cuts off.

Police reached the scene in six minutes. What they found inside would become one of Korea's most devastating cases of preventable violence.

Room 307

The door was locked. After police pounded and shouted, a trembling fourteen-year-old girl finally opened it — the one who'd made the calls. Inside, blood trailed from the front door to the bathroom, where three students lay collapsed: fourteen-year-olds Sumi Kim and Hojin Jung, and a third student, Choi, all struck repeatedly in the neck and head with a knife and hammer.

The tragedy began two weeks earlier in an open chatroom, where Sumi and her friend Lee met a man calling himself nineteen-year-old Soochul Pyo. He grew fixated on Sumi, who never returned his interest and eventually stopped replying. On December 3rd, while Sumi celebrated the end of exams with her boyfriend Hojin and two friends at a karaoke room, Pyo bombarded her and Lee with calls, demanding they come to his motel — threatening to kill himself if they refused.

Four Teenagers, One Room

Pressured, Sumi and Lee went to the motel entrance to talk it over — and Pyo suddenly appeared, taking only the two of them inside. At Room 307, he blocked Lee from entering, forced Sumi in alone, and told her to stay out. Lee ran to alert Hojin, who rushed over with Choi. When they knocked, Pyo casually let them all in — Sumi was unharmed — then ordered everyone onto the bed, confiscated their phones, made them drink, cut himself to intimidate them, and lectured them for twenty minutes about having once been in a gang.

At 4:55 p.m., his phone rang. He stared blankly at the TV — then ordered them to lie down. When they complied, he grabbed a hammer and swung it at Hojin. Hojin dodged, and Pyo stabbed him in the neck instead. As the others screamed and bolted for the door, Sumi grabbed the phone from the windowsill and called police — but the door wouldn't open. Pyo attacked Hojin again with the knife and hammer until he lost consciousness, then dragged the others into the bathroom one by one, slashing throats and swinging the hammer in what the surviving witnesses could only describe as a massacre.

Three Hours Earlier

When police arrived and Pyo saw them at the door, he grabbed his phone, cigarettes, and ID, opened the window, told Lee "you've got guts" — and jumped from the third floor. He died from the fall before reaching the hospital, and with him died any chance of a full confession or trial.

What police initially called an impulsive attack after a failed sexual assault doesn't hold up. Pyo had specifically requested a third-floor room — high enough to escape by jumping, but not so high a grown man couldn't survive it. He'd bought a weapon at a mart before returning to lure Sumi in. And just hours earlier, when his live-in girlfriend tried to leave him after enduring ongoing abuse, he'd chased her with a kitchen knife through the winter cold. She escaped to a welfare center and called police — but Pyo beat her to it, telling officers it was a misunderstanding over camping gear, and was released within hours. Officers who ran his background check knew he was a repeat sex offender out of prison for only five months, in violation of his mandatory residence reporting — and never flagged it to his probation office. Three hours later, he was in Room 307.

Final Thoughts

At his 2019 sentencing for raping a fourteen-year-old, a risk assessment had already scored Pyo as high-risk for reoffending. Prosecutors requested an electronic ankle monitor. The court rejected it as too harsh for a twenty-year-old. He served five years and walked free in July 2025 — five months before he killed two children with a hammer and knife he'd bought specifically for that purpose.

Because Pyo died at the scene, the case was closed without prosecution — and with it, any official accounting of what really happened. Police told the families little, downplayed the domestic violence call from hours earlier, and asked them to stay quiet with the media. When the story broke, online commenters seized on the phrase "open chatroom" to brand the victims as runaways and worse, forcing grieving families to fight both a legal system that had failed their children and a public willing to blame them for it.

Sumi Kim and Hojin Jung were ordinary students who had just finished their final exams. What happened to them in Room 307 wasn't an impulsive tragedy — it was the predictable outcome of a system that had every warning sign in hand and acted on none of them.