Thanks to the American fascination with confounding unsolved cases, mystery is among the most popular genres of books, movies, and television. From heists and capers to murders and robberies, the world’s greatest unsolved mysteries spark media frenzies that grab headlines around the globe. Some cases compel so much public intrigue that the facts and theories surrounding them become the basis of books, movies, plays, and documentaries decades or even centuries after the cases go cold.
The internet breathed new life into many of the world’s great unsolved mysteries, giving amateur detectives and self-directed sleuths the tools they needed to scrounge for new clues and fresh leads long after official authorities stopped searching for answers. Along the way, public fascination inevitably led to wild speculation, fantastical theories, and a hazy blur between facts as they actually happened and outrageous rumors that the media and public adopt as reality.
Stacker used a variety of sources to summarize 31 of the most enduring and perplexing unsolved mysteries, from grisly murders and ghost ships to great escapes and entire colonies of people disappearing without a trace. In some cases, the information came from law enforcement agencies like the Federal Bureau of Investigation, who have been working directly on solving the case the whole time. Other times, the source material was news reports surrounding new developments in the cases. Occasionally, organizations or individuals like authors or amateur detectives came up with the best information after dedicating years or even decades to studying and researching these baffling and unsolved scenarios on their own.
If the facts and fictions surrounding the most salacious and unbelievably true whodunnits pique your interest and stir your passions, you are not alone. Keep reading to learn about some of the world’s greatest unsolved mysteries and the leading theories about what really happened.
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On Nov. 24, 1971, a man in a business suit calling himself Dan Cooper (the media invented the popularized “D.B.”) boarded a plane from Portland to Seattle, told a stewardess he had a bomb, and showed her a briefcase with a device inside that convinced her it was real. He then demanded $200,000 and four parachutes, which the crew gave him, and when the plane landed, he released the passengers but held some crew hostage for his second demand—a flight to Mexico. When that plane was in the air, “Cooper” astonished the crew by jumping out of it into the night sky. He was never seen again. The case has baffled the FBI and the public ever since. The FBI closed the case in 2016, but there is still plenty of speculation that far exceeds the popular assumption that Cooper died during the jump that would have landed him in a remote wilderness. Some say Cooper was actually a former Army helicopter pilot named Robert Rackstraw who died in July 2019, while another theory revolves around one Lynn Doyle Cooper whose niece came forward in 2011 to say her late uncle plotted the hijacking at a family gathering in 1971.
On June 12, 1962, a headcount at Alcatraz—the most secure, remote prison in America—revealed that three inmates were missing. In their beds were dummies fashioned out of plaster and human hair, which fooled the guards the night before—all part of an ingenious and elaborate ruse that included life vests and rafts made from raincoat rubber. Despite one of the most exhaustive investigations in the FBI’s history and endless public speculation, no one knows the fate of Frank Morris and brothers John and Clarence Anglin to this day, although authorities believe they likely died in the treacherous waters of the San Francisco Bay.
In 1966, the grisly murder of a prominent family rocked Tallahassee, Florida, when 17-year-old Norma Jeannette Sims returned home from a babysitting gig to find her mother, father, and 12-year-old sister bound, gagged, shot, and stabbed to death. The case, which changed the previously quiet community forever—Ted Bundy would commit his most infamous murders at a Florida State University sorority house in the city in 1978—remains unsolved. Although a local pastor was long suspected, Leon County Sheriff Larry Campbell, who was a 24-year-old deputy and early responder that night, has said he knows of two suspects who he believes did it, although he refuses to name them to this day.
The mysterious man known as Jack the Ripper, who terrorized the Whitechapel district of London in 1888, is still the most famous serial killer in history. According to Science magazine, forensic analysts published genetic analysis evidence in 2019 that could finally reveal the long-anonymous murderer who killed and mutilated London prostitutes so long ago. They believe Jack the Ripper was a 23-year-old Polish barber named Aaron Kosminski, one of the main suspects at the time of the murders, though evidence isn’t quite strong enough to mark the case officially closed.
More than a dozen people have claimed to have killed Jimmy Hoffa since the powerful Teamsters union boss went missing in 1975 and was listed as “presumed dead” in 1982. Most recently, Martin Scorsese’s blockbuster “The Irishman” stoked new interest in a credible claim made by the movie’s namesake, mafia hitman Frank Sheeran. Even the skeptics who doubt Sheeran’s claim believe that if it wasn’t him, it was a different killer for the Bufalino crime family, with which both Sheeran and Hoffa were long associated.
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Aviation pioneer, feminist icon, and American hero Amelia Earhart made her final radio transmission on July 2, 1937, when she and her navigator disappeared while attempting to circle the globe across 30,000 miles in an airplane. In the decades since, there has been no shortage of speculation, with some theories backed up by fairly compelling evidence, including one that she was captured by the Japanese military and another that she was marooned and lived on a remote Pacific island. The most likely and widely believed scenario, however, is that she crashed during bad weather and sank in the vast Pacific Ocean near where her last broadcast was transmitted.
[Pictured: Amelia Earhart with her navigator, Captain Fred Noonan photographed on June 11, 1937.]
Few murder mysteries have remained ingrained in the public imagination longer or more deeply than the 1892 axe murder of upper-crust Massachusetts residents Andrew and Abby Borden. Andrew’s daughter Lizzie Borden was 32 and unmarried (a minor scandal for the upper class at that time) when she immediately became the main and only suspect, only to be acquitted a year later in 1893. Alternate theories have been pitched for more than a century, but Lizzie—who was home at the time and had plenty of motives—remains the only true suspect with any real evidence pointing to her as the killer.
In 1942, one of the strangest unsolved crime sprees understandably terrified the town of Pascagoula, Mississippi, when a man dubbed “The Phantom Barber” broke into homes, cut locks of hair off women and children, and left without stealing anything or otherwise harming anyone. Fifty-seven-year-old William Dolan was soon arrested and convicted—he had human hair in his home, and some victims were likely incapacitated with chloroform while he was a chemist by trade. His sentence, however, was later suspended when he passed a lie detector test and police were accused of mishandling the case in a rush to find a suspect. He remains, however, the only credible suspect.
The ship Mary Celeste left New York City for Genoa, Italy, in 1872, only to be discovered at sea partially flooded and missing a lifeboat, but otherwise intact, seaworthy, packed with supplies, and empty. The disappearance of the 10 people on board remains one of history’s greatest maritime mysteries. Books, plays, and movies were written about the many theories surrounding the ghost ship, including pirate takeovers, mutiny, waterspouts, sea monsters, and deadly rampages by former slaves. In 2007, however, Smithsonian magazine outlined exhaustive research that revealed the most likely scenario: Coal dust fouled the boat’s pumps, which led the captain to order the crew and passengers to abandon ship in the belief that he was closer to land than he really was.
The Lost Colony of Roanoke, founded in present-day North Carolina in 1587 and discovered empty in 1590, is the oldest mystery in American history, considering it took place two decades before the founding of Jamestown. Volumes have been written about what might have happened to the 100-plus English settlers who lived there, including massacres by Indians or the Spanish, enslavement, starvation, cannibalism, and failed attempts to return to England. In 2018, however, National Geographic reported on compelling research that revealed the most likely scenario: The desperate colonists assimilated into a local Native American tribe.
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Officially named the Nevada Test and Training Range at Groom Lake, Area 51 is a highly secure, highly secretive Air Force training range in southern Nevada—and the epicenter of America’s UFO/alien conspiracy theory counterculture since the 1950s. Since rumors of a UFO crash near Roswell, New Mexico, first emerged in 1947, the Air Force has investigated thousands of reports of UFOs at or near Area 51. The most likely scenario, according to Time magazine, is that civilians and military personnel alike witnessed experimental aircraft being tested there and mistook them for alien spacecraft, and government secrecy went a long way in fueling alien fever.
In 1990, two men dressed as policemen entered Boston’s Isabella Stewart Gardner Museum, tied up the guards, and stole 13 famous works of art worth $500 million in what remains the world’s largest unsolved art heist. Nearly 30 years later, in 2018, authorities renewed a $10 million reward, which generated an avalanche of tips and theories that included a mafia heist, the Irish Republican Army, rock musicians turned museum robbers, and security guards as part of an inside job. Most credibly, the FBI believes that a Mid-Atlantic crime ring led by a man who was killed in a 1991 gang war pulled off the world’s greatest unsolved art heist.
The Zodiac Killer, a still-unidentified serial murderer who terrorized Northern California in the 1960s and ’70s, got his name from the taunting letters, ciphers, and cryptograms he sent authorities and newspapers during his reign of terror. Several people have credibly claimed either to have been the Zodiac Killer or to have known who he was, but the most likely suspect is Arthur Leigh Allen, who true crime author Robert Graysmith convincingly argued was the Zodiac Killer in two separate books on the subject. Allen died in 1992.
Benjamin “Bugsy” Siegel, America’s first celebrity mobster, was instrumental in transforming Las Vegas into a destination city, one that was controlled and bankrolled by the Mafia. Siegel was shot to death in Southern California on June 20, 1947, shortly after his Flamingo Hotel opened on the Las Vegas strip. Although his murder remains unsolved, some believe that Siegel’s childhood friend and gangster mentor Meyer Lansky set up the assassination in response to disputes about how Siegel was spending money. Siegel and Lansky were portrayed as Moe Greene and Hyman Roth in “The Godfather” movie franchise.
Harry Houdini died in 1926 at 52, and to this day, the master showman’s name is still associated with great escapes or disappearing acts. Throughout his career, Houdini upped the ante in pulling off seemingly impossible escapes in increasingly dangerous and outlandish situations. He allowed a medical student to punch him in the stomach during one show, something the famously fit magician and escape artist was known to do, and it was long believed that his mysterious death was the result of internal injuries stemming from the punch. Medical professionals now believe, however, that the Hungarian immigrant born Erik Weisz more likely succumbed to appendicitis and sepsis, which would have killed him anyway, belly punch or no belly punch.
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Joseph Force Crater was a rising star in the corrupt world of New York’s Tammany Hall Democratic politics and a state Supreme Court judge when he got into a taxi and vanished without a trace in the summer of 1930. His disappearance remains one of the most high-profile, thoroughly investigated, nearly completely lead-less, and salacious mysteries in American history—the mountains of tips that poured in included rumors of philandering with showgirls, massive political bribes, mob connections, and shady insurance dealings. The people most closely associated with the case believe that he likely knew too much about the inner workings of Tammany Hall and its mobbed-up associates and that Judge Crater received the same treatment that Jimmy Hoffa would receive decades later.
[Pictured: A view of Tammany Hall and West 14th Street in New York City in 1914.]
Twenty-two-year-old aspiring actress Elizabeth Short, famously dubbed “Black Dahlia” by the media, was found dead and expertly dismembered on a Los Angeles street in 1947. The murder sparked a whirlwind of public interest and the mystery still tantalizes to this day. Although it never went anywhere, the most promising lead at the time pointed to a group of university medical students who would have been adept at dissecting bodies as cleanly as the Black Dahlia’s had been.
It was long believed that Billy the Kid, the most famous outlaw in Old West history, was killed by lawman Pat Garrett—the problem, however, is that the account that cemented that story in the public consciousness was written by Garrett himself. In the ensuing years, countless historians, amateur detectives, and plenty of imposter Billy the Kids have insisted that Billy escaped Garrett’s wrath that day in 1881 and continued his remarkable life on the run in disguise. In 1990, “Young Guns II” portrayed Billy as having lived to old age into the 20th century. Most of the facts, however, confirm that Billy the Kid’s short, violent life probably did end at the barrel of Pat Garrett’s pistol.
What’s most unbelievable about the brazen and highly public drive-by shooting murder of Tupac Shakur on the crowded Las Vegas strip in 1996 is that it still hasn’t been solved. A central figure in the East Coast/West Coast rap beef, Shakur had deep gang ties. He was riding in the car with the career criminal and record producer Marion “Suge” Knight when he was killed and his list of avowed and dangerous enemies was as long as his lengthy rap sheet. Although the media firestorm that ensued included speculation that his killers were corrupt Los Angeles police officers or East Coast rivals sent by Sean “Diddy” Combs, it’s most likely that he was killed by a crew of rival gang members who he fought in a casino earlier that evening, including Orlando “Baby Lane” Anderson, a Crip gang member who was murdered himself at the age of 23.
[Pictured: A wall dedicated to the memory of Tupac Shakur is seen on May 2016 in Los Angeles, California, 20 years after his death.]
Almost exactly six months after Tupac Shakur was gunned down, his East Coast arch-rival Christopher Wallace (better known as the Notorious B.I.G.) was murdered in Los Angeles, bringing to a close the violent cross-country rivalry that had dominated the 1990s rap world and enthralled the media and the public. Astonishingly, the Biggie Smalls murder also remains unsolved, and Wallace’s music and lifestyle similarly left no shortage of suspects with means and motive. Although unfounded speculation fueled rumors that police or the FBI were complicit in the murders of both men—who were once close friends—most fingers point to Death Row Records CEO Suge Knight as having orchestrated the murder of Wallace as revenge for the killing of Tupac.
[Pictured A man displays a T-shirt tribute to rapper Biggie Smalls as fans line the funeral procession route in Brooklyn on March 18, 1997.]
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When a six-year-old child beauty queen was brutally killed in her Colorado home in 1996, it seemed that everyone in America suddenly knew the name JonBenét Ramsey. Her parents were the original suspects, followed later by her brother, but DNA evidence ruled them out. More than a quarter-century later, the world still asks, “who killed JonBenét?” In 2019, Rolling Stone reported on compelling evidence that Gary Oliva, a convicted pedophile and longtime suspect, actually, and perhaps accidentally, committed the murder.
It’s fitting that Edgar Allan Poe, long known as the master of morbid prose, died under circumstances so mysterious that as many as nine theories still surround his unexplained death, which occurred as Poe writhed in a fit of delirium in 1849. The leading theories include murder, alcohol withdrawal, a beating, rabies, heavy metal poisoning, and carbon monoxide poisoning. According to Smithsonian Magazine, however, it was probably something much less sinister like the flu or a related illness.
In 1913, the 71-year-old Ambrose Bierce, a famous writer and Civil War veteran, left on horseback to cover the Mexican Revolutionary War and was never seen again. Theories about his death included him dying in battle, defecting to the army of Pancho Villa, and being kidnapped and killed by Federales. Most likely, however, he was caught by Mexican military authorities who assumed he was a spy and, not able to speak Spanish, was summarily executed after being unable to answer their questions.
Long Island, New York native Annie McCarrick was living in Ireland when she suddenly vanished in 1993 and, despite a massive manhunt, no trace of her was ever found. She was one of several women who disappeared in the 1990s in an area dubbed Ireland’s “Vanishing Triangle.” The area was the hunting ground of a serial killer long believed to be convicted rapist Larry Murphy, and McCarrick is thought to be one of his victims.
[Pictured: Johnny Fox’s Pub in Glencullen, where Annie McCormick was last believed to have been seen.]
The 2008 Angelina Jolie and Clint Eastwood movie “Changeling” chronicles the real-life story of Christine Collins, whose nine-year-old son, Walter, went missing in 1928. The LAPD then returned to her a different, older boy who turned out to be a willing imposter named Arthur Hutchins Jr., who later admitted to concocting the scheme to escape an abusive household. When Collins protested, she was involuntarily committed to a mental hospital and was later exonerated. It has long been believed, but never proven, that the real Walter Collins was one victim of serial killers Gordon Stewart Northcott and his mother Sarah Louise Northcott, who killed little boys in the area.
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Paula Jean Welden is the most famous of five people of all ages and genders who vanished from the small town of Bennington, Vermont, between 1945 and 1950. After the young college student disappeared in a wooded area, fear and gossip gripped the community. It’s likely that an unnamed young man originally suspected and questioned by police was a serial killer, but local cops bungled the case, which led to the formation of the Vermont State Police.
Tamper-resistant packaging on modern medicine directly results from one incident, which terrified the nation, baffled law enforcement, and threatened the country’s supply of food and drugs: the Tylenol poisonings. In 1982, a still-unknown assailant spiked Tylenol capsules with deadly cyanide, leading to the deaths of several people in the Chicago area and launching one of the most significant law enforcement investigations in modern history. A man named James William Lewis was convicted of extortion for mailing a ransom letter to Johnson & Johnson demanding money for an end to the poisonings, and although he couldn’t be pinned to the actual act, many of the lead investigators still believe he was the perpetrator.
Spooky, desolate, and remote, the Flannan Isles Lighthouse in Scotland had long been the subject of paranormal stories and superstitions. It didn’t help when an arriving ship found the lighthouse mysteriously empty with no trace of all three lighthouse keepers in December 1900. Local lore fueled wild speculation about malignant apparitions, sea creatures, and murder stoked by desolation-induced madness. Terrible weather had plagued the surrounding seas, and it’s most likely that the three men had gone down to the base of the lighthouse to secure a supply crate to mooring ropes to haul the crate up, and were swept away by a massive rogue wave.
[Pictured: Fanad Head Lighthouse, Letterkenny, Ireland.]
On March 18, 1990, the 15-year-old twin sisters Dannette and Jeannette Millbrook disappeared without a trace in Augusta, Georgia. Their disappearance remains the only case of missing twins to remain unsolved in the United States. Georgia police dismissed them as runaways and put little effort into finding the twins in the days and years following their disappearance, prompting accusations of racial bias from the Millbrook family and their many supporters. Recently, new media attention has brought their plight back into the spotlight, leading to new digging by professional and amateur investigators alike, many of whom believe they fell victim to serial killer Joseph Patrick Washington, who operated in that area at that time.
The brutal 1954 bludgeoning death of Marilyn Sheppard and the controversial conviction of her husband, Dr. Sam Sheppard is the most enduring murder mystery in Cleveland history and was the basis of the TV show and movie “The Fugitive.” Dr. Sheppard’s conviction was overturned in 1966 and he died in 1970. Today, his descendants and the investigators who still fixate on the sensational case believe the real killer was Richard Eberling, a convicted murderer and window washer at the Sheppard home.
[Pictured: Dr. Sam Sheppard (Center) was convicted and later exonerated for the murder of his wife, Marilyn Sheppard in 1954.]
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In 1978, the nation was stunned when “Hogan’s Heroes” star Bob Crane was found brutally murdered in his Arizona home. Police there are believed to have mishandled the case from the beginning and the murder remains unsolved, but the incident has continued to fascinate the public and gnaw at Crane’s surviving family. It’s believed that John Carpenter, a longtime friend of Crane’s who was arrested, tried, and acquitted in 1994 due to botched forensic evidence, is guilty of the murder.
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