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Dorothy Jane Scott's unidentified caller -

Scott, a single mother with a young son, had been receiving strange calls in California, some professing love and others violently threatening her, making it clear the caller was stalking her too. She went missing in 1980, but the killer kept calling her family until 1984, and resumed shortly after they found her charred bones.

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The Hinterkaifeck Murders -

In the winter of 1922 at the Hinterkaifeck farm in Bavaria, Germany, farmer Andreas Gruber had told his neighbors of footprints in the snow leading towards his house, hearing footsteps in the attic, finding an unfamiliar newspaper in his home, and missing house keys.

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The Hinterkaifeck Murders - Soon afterward, all six residents of the farm, ranging in age from 2 to 72, were found dead, murdered one by one in the barn with a pick axe. The mystery was so unsolvable that police removed the heads of the victims and sent them to a clairvoyant in Munich.

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The Black Dahlia -

Elizabeth Short, now known as the Black Dahlia, was found murdered and severed from the waist in Los Angeles in 1947. Details of the 22-year-old’s life are largely unknown, but her unsolved murder has been the source of books and films. The weirdest part? Some 60 people confessed to the crime, 25 were seriously considered, and none convicted.

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The Axeman of New Orleans -

From May 1918 to October 1919, an axe-wielding killer stalked New Orleans, attacking 12 and murdering six. The identity of the person was never discovered. However, the killer sent a curious letter, marked from hell, to the local papers...

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The Axeman of New Orleans -

The letter said that on March 19, 1919, whoever is listening to a jazz band will be saved from the axe. The city was full of jazz music that night, and no one was killed.

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Austin, Texas, yogurt shop murders of 1991 -

On December 6, 1991, firefighters responding to reports of smoke at a yogurt shop found within the flames four brutalized bodies of teenage girls. Eight years later, four men (teens at the time) were charged, but only two were convicted in 1999. Their conviction, however, was overturned in 2006 because their confessions were deemed false. The murders remain a mystery.

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Lady of the Dunes -

In the dunes near Provincetown, Massachusetts in 1974, the body of a woman was found with a crushed head and no hands. No one knows who killed her or why, and they also don't know who she was, despite exhuming her body several times.

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The Smiley Face Killer -

At least 45 deaths by drowning of college-aged men are attributed to the Smiley Face Killer, who allegedly leaves a smiley face near the body of water, though most police departments say he doesn’t exist. The first alleged case was in 1997, and the most recent was 2016.

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The brutal unsolved murder of the Dardeen family -

In a crime too gruesome for TV, Russell Keith Dardeen, his wife and her unborn daughter, and his three-year-old son were killed in Ina, Illinois in 1987. A serial killer named Tommy Lynn Sells confessed in 2000, along with more than 70 other murders. But only 22 were convincing, not including the Dardeen's.

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The 1959 murder of the Walker Family -

The Walker family, with parents in their twenties and two young children, were shot to death in their home in Florida. Despite upwards of 500 suspects, the case remains unsolved, though Truman Capote's 'In Cold Blood' and several detectives hypothesize a link with the Clutter family murderers Richard Hickock and Perry Smith (pictured).

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The Boy in the Box -

A young boy between three and seven years old was found wrapped in a blanket inside a cardboard box in a wooded section of Philadelphia in 1957. His corpse showed malnutrition and abuse, and though his image was distributed all over the city, he remains “America's Unknown Child.”

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The 1908 murder that inspired 'Twin Peaks' -

The fictional Laura Palmer's death was inspired by the real-life unsolved murder of Hazel Drew, a 20-year-old woman found washed ashore. Much like Palmer, she had a vibrant, secret, and chaotic personal life, which introduced many suspicious characters into the investigation. But it was ultimately left a mystery.

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Who put Bella in the Wych Elm? -

In 1943, four boys discovered a skull inside a witch elm tree (or “wych elm”) in Worcestershire, England. It belonged to a woman who had been dead for at least 18 months, and cloth was found in her throat. It only got attention after WWII ended, when graffiti appeared around the region—and it persists on the Hagley Obelisk near to where the body was found.

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The Grimes sisters -

In December 1956, teenagers Barbara and Patricia Grimes attended a showing of Elvis Presley's 'Love Me Tender' in Chicago, and never returned. The search was muddled, as people claimed they spotted the girls as far as Nashville, Tennessee, and many theorized they ran away to find Elvis. The theory was so widespread that Elvis himself asked the girls over the radio to return home.

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The Grimes sisters -

About a month later, the girls' bodies were found on the side of the road in Willow Springs, Illinois. After thawing their bodies, the autopsy found they had been killed within hours following the film. There have been theories, false confessions, and related incidents, but no conclusions.

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The vigilante murder of Ken McElroy -

Ken McElroy was known as "the town bully” in Skidmore, Missouri, where he was charged with many crimes (sexual assault, arson, assault, burglary, attempted murder, etc.) but never convicted. He was shot multiple times in broad daylight on the town's main street with as many as 60 witnesses, yet no one called an ambulance, confessed, or implicated anyone else.

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The Seal Chart Murder -

In August 1908, Major-General Charles Luard returned from a hunting trip to his house in Kent, England, only to find his wife, Caroline Mary Luard, shot and killed. Despite his alibi, many believed Charles killed her, and he took his own life a few weeks later, leaving the search inconclusive.

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The Zodiac Killer -

The Zodiac Killer transfixed California in the 1960s and 1970s with both brutal murders and the cryptograms he sent to the press. Though he claimed 37 murders, only seven were confirmed attacks, five of which were fatal. Officially, his identity remains unknown.

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The murder of Hollywood's William Desmond Taylor -

One of the most prolific directors in Hollywood was fatally shot in his LA home in 1922. This unsolved case had various stories attached to it, with corrupt investigations, wrongful reports, and suspicious disappearances of a doctor, Taylor's valet, and a gun.

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The Villisca Axe Murders -

In 1912, a neighbor entered the Moore family's house and found all six bludgeoned to death by axe, along with two girls who happened to have slept over. Somehow the killer had crept in and killed each in their beds while they slept.

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The Villisca Axe Murders -

Strange clues like a slab of bacon were left behind, and the murderer had draped cloths over the faces of his victims and covered each mirror with linen. Many were suspected, like Henry Moore (pictured, no relation to the family), but the case remains open.

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The Villisca Axe Murders -

The scene of the crime has been made into a tourist attraction for those with a dark side, as the Moore homestead is now a museum that can also reportedly be rented out for the night.

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Who killed Georgette Bauerdorf? -

A well-loved 20-year-old oil heiress was found murdered in a bathtub at her home, with no clues except an unscrewed light bulb outside her door. The killer left in her car, which turned up abandoned later, but there were no other reports of robbery.

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The Keddie Cabin Murders -

In April 1981, a mother, her teen son, and his friend were murdered in a California cabin, while her two other sons and their friend Justin Smartt slept in an adjacent room. The family's 12-year-old daughter vanished, her body found years later and miles away. The eldest daughter found the scene the next day, where the biggest mystery ended up being how a murder with so much physical evidence could remain unsolved...

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The Keddie Cabin Murders -

Smartt later said he saw two men (pictured), and clues including weapons and a fingerprint were found, but nothing came of it. Even eerier, the anonymous caller who found the daughter's bones years later identified the remains as hers, then hung up, long before investigators could confirm.

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Bible John -

During the late 1960s in Glasgow, Scotland, three brunette women were murdered after leaving a club with an unknown man who, witnesses say, would often quote from the Bible. Bible John's identity remains a mystery.

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The Texarkana Moonlight Murders -

Eight attacks, five fatal, took place over the course of 10 weeks in 1946, sending Texarkana, Texas into a panic, with businesses selling out of guns. And then everything was quiet. The white-masked attacker earned the name of the “Phantom Killer.”

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The YOGTZE Case -

In one of Germany's most mysterious unsolved cases, Günther Stoll was discovered, alive and naked, in his crashed vehicle in 1984. He was barely conscious and mumbled about four men who had been with him, but died on the way to the hospital, leaving behind a note that read YOGTZE.

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The unsolved murder of Margaret Martin -

In 1938, a 19-year-old recent graduate in Kingston, Pennsylvania allegedly got into a car to meet with a man about a secretary job. Four days later, her naked body was found in a burlap sack floating in the water some 40 km (25 mi) northwest of Kingston. Her killer was never found.

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The "Beautiful Cigar Girl" inspired true crime literature -

Edgar Allen Poe's 1842 murder mystery 'The Mystery of Marie Rogêt' is based on the real-life 1841 murder of Mary Cecilia Rogers, a young New Yorker who worked in a tobacco shop. She was found in the Hudson River, and while many had theories, like a botched abortion, neither Poe nor detectives could solve it.

See also: Watch these chilling true crime documentaries.

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