[0:00]Have you ever wondered who the very first serial killer was? And more importantly, what could have pushed someone to kill not just once, but over and over in a time when nobody even knew what a serial killer was? It's almost impossible to trace back to the very first in history. But if we turn back time about 100 years, to 1918, we can look at one of Thailand's earliest known serial killers, and the last person in the country to ever be publicly beheaded. This is the case of Boonpeng.
[0:44]This case came to light on a calm afternoon in January 1918. A few men from a village near the Chao Phraya River in Nonthaburi Province had gone out fishing, like they often did. While they were sitting by the river, waiting for a bite, they spotted something strange floating in the water— near a temple. Curious, they pulled it out. It was an old iron box. At first, they thought it might be some kind of treasure. But when they pried it open, what they found inside was straight out of a nightmare. The body of a woman cut into eight pieces. Her hands and feet were tied with rope, her internal organs were spilling out. It was so horrifying that the men could barely believe what they were seeing. Some ran straight to the nearest police station. When the police arrived, they started an initial investigation. The body was of an unidentified woman, wrapped in a mosquito net. Bricks — or according to some reports, wooden blocks — had been packed into the chest, likely to weigh it down and keep it at the bottom of the river. But without any leads, there wasn't much they could do. That is, until a rickshaw driver showed up. He had seen the news and came forward with a simple statement: “I was told to dump the chest by Boonpeng.” That one sentence changed everything. He became a key witness in the case, the first real break investigators had. So now the question became: who was Boonpeng, really? And what made him capable of committing such a brutal murder? He was born in 1890 in a remote village called Tha Uthen — a small place near a canal in what was then called Monthon Lao Phuan, now known as Nakhon Phanom Province in northeastern Thailand. His father was Chinese, his mother was Lao. That made Boonpeng half Chinese, half Thai-Isaan. According to some sources, both of his parents died when he was just five years old. After that, he was taken in by an elderly couple named Souk and Pian. They lived in Bang Khun Phrom district in Bangkok, and they raised him like their own grandson. Despite having very little, Souk and Pian loved him deeply. They gave him everything they could — food, shelter, care. He grew up in a home filled with love, even if they didn't have much else to give. As he got older, people started noticing him. As a teenager, Boonpeng was known for being extremely handsome. Not just "nice-looking" — but charming, eloquent, and the kind of guy women would stare at when he passed by. People said women would swoon just from looking at him. But good looks can be deceiving. Behind his charm, Boonpeng had a darker side. He was a lazy man. He refused to work, even when his grandparents needed a little help in the fields. Maybe it was because they spoiled him, trying to give him everything they could, but he never developed the motivation to do things on his own. Instead of working like everyone else, he became fascinated by something else entirely — black magic. He got especially interested in things like love spells, charms, and something called the twin potion — a kind of love potion that was believed to make people fall uncontrollably in love. It was all steeped in superstition. One day, he met an old man who lived near a temple in Ruamh. That man was willing to teach him everything he knew about black magic. And from that point on, Boonpeng was hooked. He started sneaking out of the house every day to learn more. His grandparents noticed the change. He started talking to himself, mumbling strange words they didn't understand. Eventually, they found out what he'd been up to — and they were terrified. Afraid that his study of black magic would bring evil into their lives, or worse, be used to hurt others, they kicked him out of the house. With nowhere to go, Boonpeng made his way to the Bang Lamphu area in downtown Bangkok. And this time, he didn't just study black magic. He started selling it. He offered services: charms, potions, spells. And not long after, the 20-year-old Boonpeng became a monk — ordained at Wat Thewarat Kunchorn, one of Bangkok's older temples. For a while, it seemed like he had found a new path. People came from all over just to receive blessings from him. With his soft voice, his clean robes, and his good looks, he drew crowds. But that image didn't last. Because soon enough, the same darkness crept back in, and this time, he began to mix black magic into his role as a monk. With his charm and carefully crafted image as a monk, Boonpeng didn't just attract worshippers, he lured people in with promises. Promises that he could change their lives. Solve their problems. Fix their broken hearts. All with a little black magic. People started lining up to see him — especially women. Many came to ask for love spells. Some were from the upper class — wealthy women who had heard talks about a monk who could mend hearts with potions. Boonpeng welcomed these women to the temple. Often at night. He was respected by many of his followers, even allowed to make money while under ordination, a rare privilege for a monk. But what people didn't know, at least not at first, was that sex had become a part of his so-called “rituals.” And in Buddhist monastic rules, especially as a bhikkhu — a fully ordained monk — sexual activity is considered the gravest offense. Eventually, word got out. The temple couldn't turn a blind eye any longer. The abbot learned of Boonpeng's behavior: the sex, the deceit, the black magic. And just like that, he was expelled. Once again, Boonpeng had no place to go. But that didn't stop him. He went back to downtown Bangkok and walked straight into another temple — Wat Suthat — a prestigious and well-known temple right in the heart of the city. As he entered, people recognized him. Some whispered, “It's him. It's Boonpeng.” Their eyes followed him through the temple grounds like he didn't belong there. They could just feel that he had brought something dark with him. But Boonpeng didn't flinch. He went to meet the head abbot and asked to join the temple. At first, the abbot refused — Boonpeng's reputation for adultery and black magic could stain the temple's good name. But Boonpeng knew how to talk. He promised to change. He claimed he wanted a second chance to walk the right path, to live as a proper monk. And somehow, the abbot believed him. So he stayed. But, of course, the promises didn't last. Instead of reforming, Boonpeng went straight back to his old ways, and worse. He opened an illegal casino inside the monk's residence. He had multiple affairs with women. He kept making and selling love potions. And somehow, he got away with it — for nine years. People believed that his reputation for effective love spells and his connections with wealthy women protected him. But behind the scenes, something far more sinister was happening. At some point, during those nine years, Boonpeng started to kill. His first confirmed victim, according to his own confession, was a man named Nai Learm, a jewelry seller. Nai had come to Boonpeng to sell him some pieces. But instead of buying anything, Boonpeng had already planned to kill him and steal the jewels. With help from his followers, he murdered the man and took everything he had brought with him. But now he had a problem — a body to get rid of. So he ordered his disciples to cut up the corpse and stuff it into another iron chest. Then they loaded it onto a rickshaw, and dragged it about 6 kilometers through town. Back then, moving something like that wasn't easy — especially without being seen. But somehow, they managed to cross over the Chao Phraya River and dump the chest into the canal. The body was found in May 1917. When locals eventually found the chest and opened it, they were stunned. Police didn't even know how to handle the case — a murder like this was unheard of. And the idea that a monk might be behind it? That was unthinkable. People couldn't even bring themselves to consider it. So Boonpeng got away with it. From there, Boonpeng began what would later be called a killing spree. It's believed he killed at least five people, most of them wealthy women who had come to him for help. One of those victims was Prik, the 20-year-old woman whose body had been discovered in the river. Prik had come to Boonpeng because she'd heard of his reputation. And she was desperate — married to a wealthy man named Khun Sittkdi, who gave her everything except affection. He spent more time with his mistress than with his own wife. Prik wanted her husband's love back, so she came to Boonpeng for a potion. But Boonpeng had other plans. It wasn't her beauty that caught his interest — it was her money. Soon, the potion meant for her husband was forgotten. Instead, Boonpeng seduced her. Despite knowing his reputation, she fell for him. Maybe it was his charm, or maybe it was the promises. Either way, she ended up in a relationship with him, behind her husband's back. Eventually, Prik became pregnant, and she was certain that the child was Boonpeng's. Her husband barely touched her anymore. So she asked Boonpeng to take responsibility. But Boonpeng wasn't thinking about fatherhood. He was planning to marry another woman — someone named Tat. And Prik's pregnancy didn't fit into that future. She had become a liability. So instead of taking responsibility, he decided to kill her. He sent her a letter saying he wanted to return her necklace and asked her to meet him. And she went — trusting him. Maybe hoping they could still find a way forward. They sat together for a while, speaking in quiet tones. We don't know exactly what was said, but at some point during that meeting, as her guard was down, Boonpeng quietly stood up, walking behind her, and strangled her with his bare hands. After Boonpeng murdered Prik and stuffed her dismembered body into the iron chest — which was wrapped in a mosquito net and packed with bricks — he stood over it for a moment and reportedly said: “Now… how do I throw this into the river?” That's when he turned to the only people he trusted to help him clean up his crime — his two disciples. One was a 19-year-old young man, the other older. Their names were almost identical: Charan and Charoen. Together, they hired a “rot jek,” a rickshaw, and began their grim task. They hauled the iron chest 20 kilometers from the murder scene, all the way to Wat Sai Ma, a quiet temple along the banks of the Chao Phraya River in Nonthaburi. That's where they dumped the chest, thinking the bricks would weigh it down enough for it to disappear forever beneath the current. But they were wrong. In early January 1918, a group of villagers were out fishing along the riverbank. That's when they spotted a medium-sized iron box floating toward them. At first, they were excited. The chest looked expensive — the kind of box only used by wealthy people. Maybe it had treasure inside. They worked together to pull it from the water. But when they pried it open, there was no gold. Instead, they found the dismembered body of a woman. At first, the body was wrapped tightly in a net, so they thought the person inside might still be alive. But once they pulled back the net, it was clear: she'd been dead for days. The police didn't waste any time. They started a frantic investigation, questioning fishermen, passersby, anyone who might've seen something around the river that day. But nothing came up. There were no leads and no witnesses, just the body of a young woman crammed into a chest. With no other options, the police decided to release her description to the public. They published everything they could — her appearance, the condition she was found in — in a local newsletter. They were hoping someone out there had a missing daughter and might recognize her. And not long after, a woman came forward. As soon as she arrived at the station and saw the description, she burst into tears, calling out her daughter's name — Prik. She told the police that her daughter had left home after receiving a letter from a man named Boonpeng. The mother also mentioned she had heard of Boonpeng before — not from personal experience, but from rumors. Stories about a notorious monk from Wat Suthat — a man known for dealing in black magic. And adultery. With that tip, the police turned their attention to Boonpeng. But again, they hit a wall. They had no solid evidence. And every time they questioned him, he denied everything. So they tried once more. They made another public appeal, this time with Prik's confirmed identity. They asked if anyone had information that could link Boonpeng to her death. And finally, someone spoke up. It was Charan, one of Boonpeng's own students. He told the police that he had helped dump the iron chest with Prik's body into the river. But that wasn't all. He also told them something even more shocking. He revealed that this wasn't the first time Boonpeng had killed. That was all the police needed. On January 14, 1918, during Boonpeng's wedding ceremony — yes, he was getting married — police arrived and arrested him. Guests were stunned. Even though many knew his reputation, they didn't expect to see him dragged away in handcuffs, right in the middle of his big day. Even more disturbing was Boonpeng's expression. He was seen calm. Almost blank without any emotion. No sign of regret at all. It was as if killing someone — even someone carrying his child — meant nothing to him. While he was in custody, the police pressed him about Prik's murder, and then asked if he had ever killed before. That's when he confessed to the murder of Mr. Nai. Now with two confirmed murders, investigators looked deeper. They began to suspect that Boonpeng was responsible for more. Up to five other disappearances were connected to him — mostly women who had been romantically involved with him. Each case had the same eerie pattern: the victim went missing, and sometime later, a sealed iron chest would be found in a canal. People from the temples where Boonpeng had stayed, even reported seeing seven iron boxes stored in his room — all of which vanished over time. Presumably, one for each victim. But Boonpeng never admitted to killing more than two. Even until the very end, he refused to confess to the other murders. There's no detailed record of how the court process unfolded, but in the end, the investigation concluded with Boonpeng being charged for two murders — Nai and Prik. As for his two disciples, Charan and Charoen, the ones who helped Boonpeng — there's no official record of what punishment, if any, they received. But Boonpeng was sentenced to death. On August 19, 1919, he was publicly executed, beheaded in front of a crowd. He was tied to a wooden pole as the executioner entered the space, sword in hand, performing a ceremonial dance — a tradition before executions at the time. The crowd gathered in silence, watching the man whose name had become infamous. Some pointed, others whispered. Boonpeng didn't flinch. What happened next depends on who you ask. According to local folklore, something strange occurred. As the sword touched Boonpeng's neck, it didn't cut. The blade, said to be razor-sharp, felt as if it had gone dull. The executioner paused. He noticed something. Boonpeng's lips were moving. He was reciting something. Possibly a dark spell. The executioner leaned in and said, “You have something protecting you. Take it out.” And then, Boonpeng opened his mouth and spat out a small black Buddha amulet. Once it was removed, the executioner repeated the sword dance, and this time, the blade tore clean through his neck. Blood spilled onto the ground. His head dropped. And yet, some who stood closest said, even after he was decapitated, they could still see his mouth moving. Perhaps casting one final spell. After his death, Boonpeng's body was buried at Wat Pasi, near the San Saeb Canal. The chests used to hide the victims' bodies were said to be buried beneath the temple grounds. People believed Boonpeng's spirit still lingered around the area, but over the years, it transformed from something feared into something strangely respected. Over time, locals built a shrine in his name — not to honor what he did, but to appease his spirit, to ask for peace, to stop the evil from spreading. To turn a feared ghost into a protective one. Some even started calling him “Uncle Boonpeng.”
[19:09]He became the subject of folk legends, ghost stories, and even movies, including the 2015 film, The Black Coffin. And although some people claim his spirit now protects the area, others still say they feel a chill every time they walk past the shrine as if someone's watching. And that's the end of the case of Boonpeng Heep Lek, Thailand's first known serial killer and the last person in the country to be publicly beheaded. What bothers us is that so much remains unclear, not just how many people he killed, but how someone in a position of spiritual trust was able to carry out such crimes for so long. Seven iron chests were said to have been seen in his room. Only two victims were ever named. The rest, we will probably never know. This case leaves us with a few things to think about: What happens when belief and fear are exploited by someone in power? Why do some people turn to dark practices? Is it for control, or to fill something missing in themselves? And how do communities process crimes like this, where spiritual belief, trust, and violence all intersect? Boonpeng's story isn't just about a killer. It's about how people can be drawn in by appearances and how those appearances can be used to hide the worst intentions. Let me know what you think in the comments, and if you've heard of similar cases where crime and belief overlap — feel free to share them. That's all for today. Thanks for watching.
