21 of the Most Famous Unsolved Mysteries in US History

No other murder in U.S. history has captivated public fascination for as long as the brutal bludgeoning of the Bordens. Lizzie Andrew Borden is widely believed to have beaten her affluent father and stepmother to death with an ax handle, possibly with the involvement of a housemaid. However, a court ruled the evidence against her was circumstantial, leading to her acquittal. She spent the rest of her life ostracized by her community. The murder captured the public’s attention at the time and continues to show up in popular culture, most recently depicted in the 2018 film “Lizzie.”

One of the most horrific unsolved multiple homicides in American history occurred on the night of June 9 in Villisca, Iowa. Known as the “Villisca axe murders,” a husband, wife and six children aged 5 to 12 were viciously bludgeoned to death with an ax. Despite nearly a decade of investigations that led to the creation of Iowa’s state investigation bureau, the crime is still unsolved. Lyn George Jacklin Kelly, a traveling preacher with a history of mental illness, was detained and charged, but a deadlocked jury acquitted him.

An unusually high number of unexplained disappearances have occurred in a wooded area near Glastenbury Mountain in southwestern Vermont. Between 1945 and 1950, five people vanished,  including a 53-year-old woman whose body was later found, while the others were never recovered. In 1992, author and folklorist Joe Citro called this area “the Bennington Triangle.” He noted that while some believe the disappearances are just a coincidental “cluster of vanishings,” others suspect foul play might be involved. Despite some local folklore, it’s unlikely that UFOs or Bigfoot are involved.

On the evening of August 6, 1930, a 41-year-old New York Supreme Court justice vanished after leaving a Midtown Manhattan steakhouse on his way to a Broadway play. Because of his role as an arbiter of justice during the Prohibition Era in a major U.S. city, he undoubtedly had enemies. Despite intensive investigations, neither his body nor any suspects were ever found. For a time after his high-profile disappearance, the phrase “pulling a Crater” was used to describe someone leaving a social gathering unannounced.

On Christmas Eve in Fayetteville, West Virginia, a fire broke out in a house where only four of nine children escaped. The fate of the other five children remains a mystery, as their remains were never found. There was speculation that they had been abducted, with some witnesses claiming to have seen the children alive afterwards. Twenty years after the fire, the children’s mother received a photo in the mail of a man labeled Luis Sodder, believe to be one of the missing children, who was 9 years old at the time of the fire. Despite this, the local fire chief said at the time that the fire burned hot enough to completely cremate the children.

Similar to many modern cases of male violence against women, the gruesome murder and dismemberment of this 22-year-old aspiring Los Angeles actress focused on her reputation, history of underage drinking, and the way she dressed. Elizabeth Short, posthumously dubbed the “Black Dahlia” was given this nickname because she allegedly preferred sheer black dresses and as a nod to the 1946 film “Blue Dahlia,” which is about the murder of an unfaithful wife. No suspect was ever arrested, and the case eventually went cold.

The mobster instrumental in developing the Las Vegas Strip was gunned down in Beverly Hills on June 20. It’s widely believed mob boss Meyer Lansky ordered the hit because Siegel was spending too much of Lansky’s money on developing the Flamingo Hotel on the Strip. In 2014, the widow of truck driver Mathew “Moose” Pandza claimed that her late husband murdered Siegel over a love affair Moose was having with the wife of Siegel’s best friend and business partner, but the case remains unsolved.

The bodies of the 13 and 15 year old Chicago sisters were found on a country road a month after their disappearance. Investigators originally focused on a “local drifter,” but he was never formally charged. In a 1950s version of media “clickbait,” journalists exploited the fact the sisters had gone to see the newly released Elvis Presley film “Love Me Tender” to draw attention to the story. This superficial link to Elvis led to wild speculation that the girls had secret lovers or ran away to Presley’s hometown of Memphis hoping to meet the rock ‘n roll star. Like a viral TikTok fad, the public lost interest, and the case went cold.

The famous island prison, located just over a mile off the coast of San Francisco, shut down in 1963 due to high operating costs. Today, “The Rock,” as it was known by inmates and prison guards, is part of the National Park Service. For nearly 30 years, it held notorious prisoners like gangsters Al Capone and George “Machine Gun” Kelly. Among its other famous inmates were brothers John and Clarence Anglin and Frank Morris, who in 1962 executed an elaborate escape plan using three papier-mâché heads to make it appear they were sleeping while they crawled through the ventilation system. One possible scenario is that the men drowned and their bodies were swept to sea, but the U.S. Marshals Service has kept the case open “in the unlikely event the trio is still alive,” according to the FBI.

Kilgallen’s official New York City death certificate states that the co-host of the popular game show “What’s My Line?” died from a lethal mix of alcohol and barbiturates, with the circumstances marked as “undetermined.” However, her death sparked widespread speculation. Was it an accidental overdose? Suicide? Or, as some claimed, a disguised murder? Adding to the intrigue was a 911 call around the time of her death alleging that Kilgallen had indeed been murdered. Investigators never identified a suspect or resolved the case.

One of the most infamous unsolved serial murder cases is that of the “Zodiac Killer,” an unidentified Northern California murderer who used this nickname to conceal his identity in handwritten encrypted letters sent to the police and local media. While he claimed to have killed 37 people in the 1960s and 1970s, investigators linked him positively to only five murders and two attempted killings where the victims escaped. On Oct. 6, 2021, a group of independent investigators claimed to have identified the killer as Air Force veteran and gang leader Gary Francis Poste, who died in 2018. However, the San Francisco police still classify these murders as unsolved.

One of the most famous heists in history occurred on November 24, 1971, when a man identifying himself as Dan Cooper (also known as D.B.) bought a one-way ticket from Portland, Oregon to Seattle, Washington on Northwest Orient Airlines. During the flight, he used a fake suitcase bomb to ransom passengers for $200,000 and four parachutes, which were delivered to him when the plane landed in Seattle. He then instructed the pilots to fly to Mexico City but jumped from the plane with the money somewhere between Seattle and Reno. In 1980, a boy discovered a package containing $5,800 in rotting $20 bills, which were identified by their serial numbers as part of the ransom money. However, Cooper was never found, and the FBI says the case remains an “intriguing mystery.”

The notorious Teamster had numerous enemies due to his connections to organized crime and his convictions for jury-tampering, mail fraud, and bribery. However, his disappearance remains one of the most enduring criminal mysteries. Hoffa was last seen in the parking lot of a Michigan restaurant in 1975, and although officials declared him dead in 1982, his body was never found. The only piece of evidence was a strand of hair matching his DNA found in the backseat of a car. The search for Hoffa’s remains continued into the 2000s, including unsuccessful searches beneath a Detroit swimming pool in 2003 and beneath the floorboards of another Motor City property the following year.

Crane is most remembered for his portrayal of Col. Robert Hogan inthe 1960s TV sitcom “Hogan’s Heroes,” which was about a group of American POWs in Nazi Germany. He also became known as what the Associated Press described as a “skirt-chasing actor” who filmed himself having sex with women. When Crane was discovered dead in a Scottsdale, Arizona, apartment from blunt-force trauma with an electrical cord around his neck, suspicion surrounded John Henry Carpenter, an electronics salesman who collaborated with Crane on amateur films. Although blood matching Crane’s type was found in Carpenter’s vehicle, insufficient DNA testing at the time resulted in Carpenter’s acquittal in 1994, four years before his death.

In a tragic incident in the small southeastern village of Craig, a man, his pregnant wife, their two children, and four deckhands on a fishing boat were fatally shot on Sept. 6 in Alaska’s deadliest unsolved multiple homicide. Following the massacre, the killer sailed the 58-foot boat to a nearby secluded bay, even waving at a passing skipper as he left. Strangely, the killer returned to the boat the next day and set it on fire using gasoline, before fleeing the scene and the village. Investigators were only able to determine that the suspect was a young white man with a pockmarked complexion.

Seven people in the Chicago area were murdered in the infamous Tylenol poisoning incident, where bottles of the popular pain and fever reliever were laced with cyanide and returned to store shelves, targeting unsuspecting people. The poisonings led to the implementation of tamper-proof packaging regulations across the U.S. The case remains unsolved, though in January 2023, CBC Chicago reported obtaining documents through a Freedom of Information Act request revealing that investigators had analyzed the DNA of a woman and her deceased father, whose fingerprints were found on a contaminated bottle. Investigators said the DNA testing was part of a proceess to eliminate potential suspects, but did not disclose further details on what prompted them to conduct the tests nearly three decades after the crime.

In a heist worthy of a crime thriller, unknown men disguised as police officers investigating a disturbance at the Boston art museum made off with works by Degas, Manet, Rembrandt, Vermeer, and other masters. Boston Globe reporters Stephen Kurkjian estimated the value of the stolen paintings could exceed $500 million, though he noted that they are unsellable in any legitimate art market. This adds to the mystery of the case, as the motive for the unsolved crime remains unclear. Today, visitors to the museum can still see the empty frames where the masterpieces once hung.

After the infamous double-murder trial of O.J. Simpson in the mid-’90s, someone made the joke that “The Los Angeles Police Department has framed a guilty man.” This refers to what many believe to have been a straightforward case where the pro-football hall of famer murdered his ex-wife and her friend in a jealous rage on June 12, 1994. Although Simpson’s defense suggested that LAPD detective Mark Fuhrman, a key investigator, who was a racist, in the double homicide, they never directly accused him of planting a bloody glove as evidence. The trial, which exposed deep racial divisions in the U.S. justice system’s treatment of Black Americans, ended with Simpson’s acquittal. Officially, the case remains unsolved.

A 9-year old girl was abducted while riding her bike in a grocery store parking lot in Arlington, Texas. Her body was discovered nearby five days later showing signs of sexual assault. What could have been a random tragedy and another forgettable unsolved abduction and murder case ended up having a positive outcome: the creation of the “Amber Alert” early-warning child-abduction system. The Department of Justice reports that as of January 2023, the nation’s 82 Amber Alert programs have led to the rescue of over 1,127 children. Unfortunately, Amber Hagerman’s abductor and killer was never found.

The six-year-old beauty pageant winner was found dead in the basement of her Boulder, Colorado, home a day after Christmas, in a case that captured national attention. The circumstances surrounding her sexual assault and murder by blunt-force trauma and garrotting remain speculative. Suspects included her parents, her nine-year-old brother, a family friend who had dressed as Santa Claus at a recent party, and an unknown intruder. The investigation was compromised when supporters who arrived shortly after the police were allowed to wander around the crime scene, with some even helping to clean up the kitchen before an evidence sweep was completed.

The murder of rapper Notorious B.I.G.

Christopher “Notorious B.I.G.” Wallace, 24, was killed by four gunshots in a drive-by shooting after leaving a Soul Train Awards after-party in Los Angeles on March 8th,  just after midnight. The New York City-born rapper’s murder occurred six months after Tupac Shakur was fatally shot in a drive-by in Las Vegas. Both Tupac and Biggie Smalls, as Wallace was also known, were central figures in the East Coast hip-hop scene. Conspiracy theories allege Wallace plotted Tupac’s killing over a dispute, while others suggest both rappers were murdered by West Coast gang members over petty differences.