Episode 133:
The Killer Knew Exactly Where the Mailman Would Be Next
On the morning of March 3, 2011, mail carriers at the South-Incheon Post Office noticed something was wrong. 33-year-old Young-gil Kim, who in four years on the job had never once been late, wasn't there. He'd been unreachable since the previous afternoon. Worried, his colleagues put their own deliveries on hold and began retracing his route, eventually finding his motorcycle parked alone outside an apartment complex in Guwol-dong.
Checking the building's emergency stairwell — the shortcut carriers used to save time — they found Young-gil slumped on the landing between the 16th and 17th floors, a work glove stuffed in his mouth, his head caved in, blood streaming down the stairs. He hadn't even closed his eyes.
A Carrier Who Never Missed a Day
Young-gil wasn't a full-time employee but a contract worker, motivated to keep his spotless record by his widowed mother's medical bills and an upcoming exam that could finally secure him a permanent position. At the time, carriers in the area were routinely handling around 2,600 deliveries each, making stairs — faster than waiting on elevators — a normal part of the job. At his funeral, mourners assumed his death was another case of the overwork that had become a genuine problem in the postal system. Days later, the autopsy results proved otherwise: Young-gil hadn't fallen. He'd been struck repeatedly in the head with a blunt object. This was murder.
The Debt No One Knew About
Investigators narrowed the time of death to the afternoon of March 2 and pulled security footage from the area, finding a man in a mask and cap who had entered the building just before Young-gil and left an hour and twenty minutes later — exactly matching the estimated window of the attack. Tracing his movements further, they discovered he had shadowed Young-gil for two hours beforehand, arriving at each delivery stop just minutes ahead of him. Whoever this was clearly knew his entire route. But everyone who knew Young-gil described him the same way: gentle, easygoing, without enemies. The real lead came from his finances — records showed he'd taken out roughly $29,000 in high-interest loans from over a dozen lenders and transferred nearly all of it, in ten separate payments, to one person: his close colleague of four years, 43-year-old Yoon, the same man who had cried harder than anyone at Young-gil's funeral.
An Alibi That Fell Apart
Brought in for questioning, Yoon produced his PDA delivery log showing he'd been in a completely different area at the time of the murder — then broke down sobbing when asked about the money, claiming through tears that he had actually been the one lending money to Young-gil. His extreme reaction only deepened police suspicion, and other carriers soon told investigators Yoon habitually borrowed money and made excuses not to repay it, and had oddly reversed the story right after Young-gil's death. An ATM camera from two months earlier placed Yoon in clothing matching the masked man on the crime-scene footage, and internal post office cameras caught him slipping a hammer into a delivery box that same morning. His alibi collapsed completely once police discovered his PDA had no GPS function — it was a handwritten log he could freely falsify, and every "delivery" on it turned out to be fabricated when investigators visited the actual addresses. Facing arrest, Yoon fled with a four-page suicide note insisting on his innocence, and was finally caught nine days later hiding in an Incheon spa after his phone signal traced his path across the country.
Under questioning, Yoon admitted the truth. The debt began in 2009 after his own business failed; Young-gil, wanting to help a struggling friend, took out the loans in his own name and handed him the cash. Yoon never repaid so much as the interest, and as Young-gil sank deeper into debt trying to cover it, Yoon — who owed money to several other coworkers too — realized that if Young-gil simply disappeared, he could claim the debt had run the other way. His first attempt, poisoning a cup of coffee the night before, failed only because Young-gil happened to bring his own. The next day, he tailed Young-gil for two hours before luring him to the stairwell to "talk," then struck him from behind with a hammer 17 times once his guard was down.
Final Thoughts
Yoon was convicted of murder and sentenced to 20 years in prison. But the case didn't end there for Young-gil's family: because the loans were legally in his name, the roughly $29,000 debt Yoon had spent passed directly to his surviving relatives after his death. The post office denied his family a survivor's pension since he'd been a contract worker, and the case wasn't ruled a work-related death either. In the end, it was reportedly Young-gil's younger sister who took on the debt herself, just to protect her brother's name.
Yoon staged an elaborate breakdown at Young-gil's own funeral and even cried while reenacting the murder for police, all while his handwritten PDA delivery logs -- which had no GPS and could be entered by hand -- gave him a fabricated alibi. What do you think it says about the case that it was actually his overreaction to routine questioning, not the fake evidence, that first made investigators suspicious of him?
WE DOCUMENT.
YOU DECIDE.
Our interpretation is only one possible perspective.
