These unsolved murder mysteries have been keeping Ask Reddit users up at night.

1. The Vending Machine Killer

“The vending machine killer. In 1985, somebody in Japan laced beverages with poison and placed them near vending machines — people drank from them and died. Ten people died in total before the murders stopped abruptly. The identity of the killer remains a mystery.” — exodus010

2. The Hinterkaifek murders

“The Hinterkaifek murders took place in Germany in 1922. All six inhabitants of the farm were murdered with a mattock. The residents of the farm reported strange occurrences, such as footprints leading towards the farm but not away from it. Some keys went missing, and the maid claimed the house was haunted. After the bodies were found, it was obvious that someone had been living in the farmhouse for a few days after the murders were committed. So it looks like the killer snuck into the house before the murders and stayed there afterwards. No one was ever charged with the crime.” — MusicOfTheAinur

3. The assassination of Georgi Markov

“The assassination of Georgi Markov. On 7 September 1978, in London, UK. Markov walked across Waterloo Bridge spanning the River Thames, and waited at a bus stop to take a bus to his job at the BBC. He felt a slight sharp pain, as a bug bite or sting, on the back of his right thigh. He looked behind him and saw a man picking up an umbrella off the ground. The man hurriedly crossed to the other side of the street and got in a taxi which then drove away. He had been hit in the leg by a micro-engineered pellet containing ricin, fired from an umbrella. He died 4 days later. Speculation of KGB involvement has been suggested but the case remains unsolved.” — Mrdepressed90

4. The Boy in the Box

“The Boy in the Box. Back in 1958, the body of a little boy was found in a box in a forest in Pennsylvania. To this day, he has never been identified. People have theories about what happened. Most likely he was an abused child, since he was clearly emaciated (you can clearly see his ribs in the autopsy photos, which are easily available online). There’s also evidence that he’d been sitting in water before his death (wrinkling on his skin suggests this) and he’d apparently had a violent haircut, but it’s impossible to say if that happened before he died or if it was afterward and an attempt to hide his identity. If they couldn’t figure out who he was in the late-50s/early-60s, I don’t see how they’re going to figure it out today.” — PAKMan1988

5. The Moor Murders

“Ian Brady and Myra Hindley tortured and killed 5 children in Manchester in the 60s. They buried some of the victims in the moors however they never found one of the victims, Keith Bennett and people believe he is buried somewhere on the moors. Myra died a while ago, and Ian died yesterday/today so the chances of finding his body and what happened to him is very unlikely which is sad.” — bored_at_work_123

6. East Area Rapist/Original Night Stalker

“Have you heard of the EAR/ONS (East Area Rapist/Original Night Stalker)? The most prolific offender possibly in history. During the mid 70s-80s, he raped at least 50 times, in California, doing fucked up shit like breaking into houses and unloading the guns, so when the victims attempted to defend themselves, their guns only went click click with impotent failure. He liked to attack couples, and then would escape police by vaulting over fences, or jumping from rooftop to rooftop while shooting. He graduated to serial killing as time went on, and was only connected to the killings via DNA in the early 2000s. No one seems to know who this guy is, and more shockingly, most people have never heard of him. Probably the most fascinating unidentified criminal I am aware of. There is an online community dedicating to solving this case, so if you know anything, or have interesting resources, please get involved! If he is still alive, he would only be in his mid 50s, or early 60s, most likely.” — PermanentBrunch

7. Lyle Stevik

“Lyle Stevik. Man uses a pseudonym (Lyle Stevik is a character from a book who attempts to kill themselves) to check into an Amanda Park, Washington Motel then hangs himself on a clothing rack using his belt. He was acting strangely in the days before, pacing back and forth on the highway, never really leaving his room except to request new towels. After a few days of inactivity, a maid opens up his room to discover his body. The scene revealed nothing about this dude. He used a prior address to a hotel in another state which ended up being a dead end. He had zero identification on him. He had no personal belongings besides a travel sized toothpaste container, and toothbrush. He leaves $160 ‘for the room’ and investigators find a crumbled up piece of paper that says ‘Suicide’ in the trash can. His teeth were in excellent condition, and so were the clothes on his back. Recently, isotope results say that he traveled extensively throughout the country. Who is this guy? He’s somebody’s son, friend, prior coworker. It really is a mystery that’s going on 16 years of mystery. He killed himself a few days after 9/11, and some think there’s a connection, but I personally believe it’s just a red herring. I hope this case is solved one day. The photos of the scene are incredibly tragic.” — zfinne

8. Brian Shaffer

“What I’m mostly curious about is Brian Shaffer Missing Case. He was a medical student who had a bright future. On April 1, 2006 he suddenly disappeared after separated from his two friends in the bar and his last seen was filmed in front of the bar’s entrance. The strangest part of this is there’s only one entrance in the building, that entrance is constantly monitored by several nearby security cameras. He didn’t go outside, just re-entered the bar, and never showed up again. His father died 2 years later the disappearance of his son and Brian’s girlfriend, who is currently married with someone else, is still busy finding any of his trace. Nevertheless, there’s no evident clue ever found and Brian Shaffer is still missing.” — McGarfield

9. Tara Calico

“Most of them, sadly. I’m still losing the most sleep over Tara Calico, because of that photograph. For those unfamiliar with Tara Calico’s disappearance, she was a teenager who went missing, then a polaroid was found in a parking lot of a girl believed to be Calico and an unidentified boy, both bound and gagged. The look in her eyes is absolutely haunting.” — CLearyMcCarthy

10. Amber Tuccaro

“In my province there was this girl named Amber Tuccaro that went missing and was later found dead. Before she died she received a call from her brother who was incarcerated, the call was recorded and you can hear her panicking about the direction they were going and her killer trying to reassure her. The call was released by the RCMP. Its chilling to say the least.” — TommyChongUn

11. The Cagots

“Who the Cagot people were and why they were so ostracized. It’s probably my favorite historic mystery and if I could have the answer to just one, I’d pick that. ‘Cagots were shunned and hated. While restrictions varied by time and place, they were typically required to live in separate quarters in towns, called cagoteries, which were often on the far outskirts of the villages. Cagots were excluded from all political and social rights. They were not allowed to marry non-Cagots, enter taverns, hold cabarets, use public fountains, sell food or wine, touch food in the market, work with livestock, or enter the mill. The Cagots were not an ethnic group, nor a religious group. They spoke the same language as the people in an area and generally kept the same religion as well. Their only distinguishing feature was their descent from families identified as Cagots. Few consistent reasons were given as to why they should be hated; accusations varied from Cagots being cretins, lepers, heretics, cannibals, to simply being intrinsically evil. The Cagots did have a culture of their own, but very little of it was written down or preserved; as a result, almost everything that is known about them relates to their persecution.'” — 0xMii

12. Austin’s Yogurt Shop Murders

“Each victim had been shot in the head, thus leading police to determine that they had likely died before the fire was started.” — Zangypoo

13. Jaryd Atadero

“I was driving home one night from work, listening to Coast to Coast and they had this author of this book called ‘Missing 411’ on. I listened to the whole segment, even after I had pulled into my driveway. It was disturbing to say the least, but this little boys disappearance is really what sparked the author to start writing about a bunch of strange, unexplainable disappearances in our National Parks. Check it out.” — NotSoMrKniceGuy

14. JonBenét Ramsey

“I was watching something recently about this, a team of forensic people re-evaluated the case again and the main conclusion is they believed the older brother hit her in the head with a hammer and the parents covered it up and did the whole kidnapping thing. Nothing has come of it though and I think the brother is suing one of the people.” — derpman86

15. Jack The Ripper

“The identity of Jack The Ripper. Everybody involved in the case, or even alive when it happened, are long dead and buried.” — CswBizzel

16. The Monster With 21 Faces

“The Monster With 21 Faces case, the famous extortion case where a cabal of people poisoned various candies and extorted money from the confectionary companies who sold them. They also taunted the police with letters and such, and the case was so hard to crack that one high-ranking police officer committed self-immolation out of shame. Nothing ever came out of it save for a few persons of interest who were never caught, and the statute of limitations has already passed.” — Wheres_The_Pepsi

17. The murders in Kentucky

“This one is mostly of local interest, but the murders that have occurred over the last few years in Bardstown, Kentucky. A police officer shot and killed in an ambush setup, a mother and daughter that were tortured and killed together, one girl disappearing into thin air with suspicion on her police officer boyfriend, and then the girl’s father being killed not long after.” — OperationHumanShield

18. The deaths of Aselsan employees

“A lot of you won’t be familiar with this but the mysterious deaths of Aselsan employees in Turkey said to be “suicide”. Many people claim they were taken out by a group of people that did not want some codes to be cracked for the F-16’s that were being modernized.” — onceuponacrime1

19. The location of Keith Bennet’s body

“The location of murder victim Keith Bennet’s body. He was one of a number of children who were tortured and killed and then their bodies disposed on Saddleworth Moor. His mother spent her whole life searching and begging the murderers to reveal where the body was buried. She even persuaded the police/prison to release them for a day to go to the moors and ‘jog their memory’, but they used this more as an excuse for a field trip. She died a year or two back having never found out. The fucker who did it took the location to his grave last week.” — leeisawesome

20. The death of Carloman

“The exact cause of death of Charlemagne’s brother, Carloman. In the 8th century, after the death of their father Pepin, the Frankish kingdom was split in half in such a way that made both of his sons joint kings of the Franks. Charlemagne ruled in the west and Carl in the East (I think Charlie ruled from Vermandois and Carl from Troyes, which is more North/South but someone can correct me). One day Carl fell gravely ill and died, Charlemagne taking over as sole king of the Franks. Although one theory is that Carl did not die of a sudden illness, but was in fact assassinated by his own mother. It is said that their mother favored Charles, and went to Carl to try to convince him to give her favorite (eldest) son more power. When Carl refused, she left, and he fell gravely ill and died not long after. Perhaps she poisoned her own son so that her favorite may rule as king? If so, you could claim that she may be one of the most influential characters of history, as Charlemagne would go on to conquer the Saxons and the Lombards and be arguably crowned the first Holy Roman Empire, with his empire spanning most of Christianity. Crowned by the Pope as the true Roman Empire (he refused to recognize the iconoclast Byzantines as the successors to Rome because Eirene, a woman whose history is also very interesting, had taken the throne), Charlemagne’s ancestors would go to rule most of Christian europe for another century.” — EgoCibum

21. The murder of Natalee Holloway

“The guy who probably killed her is now serving 28 years in a Peruvian prison for killing another girl. He got away in the Holloway case because his father was a lawyer with all sorts of friendly connections with several judges. But after his father died, there was nobody to help him get away with the other murder in Peru.” — plusoneforautism

22. A girl my mother knew was murdered and stuffed

“When my mom was growing up, one of her friends mothers went missing, and turned up murdered and stuffed in her deep freeze. It’s considered one of my provinces top unsolved crimes and it freaks me out to think about.” — mly3rd

23. A girl from my high school was murdered

“I don’t think it ever made national news, but a girl I went to high school with went to college at the Juilliard school in NYC was murdered back in 2004. She went out running and never came back, a few days later her body was found in a park. I don’t recall what her cause of death was, but she was found naked as well which I’m told is an indication of rape. Her name was Sarah Fox, if anyone cares to search for her.” — BloodAngel85

24. Two people stole an American Boeing 727

“I can’t remember all the details since I’ve only read about it once or twice. Two people stole an American Boeing 727 from an airport in Africa. Never to be seen again. Now I swear to god this has to be the best heist in all of history because it was at an airport where there’ll be loads of witnesses and a plane isn’t exactly the smallest thing to steal. Plus you need to know the procedures to start it up and ground crew to help, so surely there has to be someone who knows exactly what happened.” — AllAboutGuitar

25. My mom’s cousin went missing in the 70s