10 Puzzling Unsolved Crimes

A 2013 photo of the Isabella Stewart Gardner Museum, showing the vacant frame from which Rembrandt's The Storm on the Sea of Galilee was stolen.
A 2013 photo of the Isabella Stewart Gardner Museum, showing the vacant frame from which Rembrandt's The Storm on the Sea of Galilee was stolen. / FBI, Wikimedia Commons // Public Domain

Unsolved crimes are exhaustively covered in the media, but chances are, there’s at least one from history in this list—adapted from an episode of The List Show on YouTube—that you’re not familiar with. From unsolved art heists to mysterious crimes committed against (or by?) royals, these unusual offenses will have you wishing for a 17th-century Robert Stack.

1. The Murder of Henry Oakes

Do you know about the gold mine tycoon whose mysterious murder eventually pulled the Duke of Windsor, Ernest Hemingway, and Meyer Lansky into its messy orbit?

Harry Oakes was a millionaire who made his fortune striking gold in Canada. In the late 1920s, he moved to the tax-free haven of the Bahamas, and by 1940 he was one of the richest people in the world. His philanthropy even helped him become a baronet known as Sir Harry Oakes.

After his violent death in 1943, which included a fatal bludgeoning and an apparent attempt to set the body on fire, the police investigation was quickly taken over by the governor of the Bahamas: Edward VIII, the Duke of Windsor and former king of the United Kingdom, who happened to be Oakes’s close friend. 

Edward’s hand-picked investigators soon identified Oakes’s son-in-law, Alfred de Marigny, as a prime suspect. They even claimed to have found a perfect fingerprint at the scene of the crime that matched de Marigny. 

At trial, though, that evidence quickly began to crumble under cross-examination. Defense Attorney Godfrey Higgs went so far as to accuse one of Edward’s men, Captain James Barker, of planting the fingerprint. With holes in Barker’s story and not much other evidence tying the defendant to the crime, the jury acquitted de Marigny in less than two hours.

De Marigny’s wife, Nancy, had stood by his side throughout the investigation into her father’s murder. Shortly after the trial, the couple left the Bahamas—according to some sources, to go stay in Cuba with their friend, Ernest Hemingway.

Some still think de Marigny is the most likely culprit: He and his wife stood to make a boatload from an inheritance after Oakes’s passing. But alternate theories abound.

In his book, Who Killed Sir Harry Oakes? Marshall Houts points the finger at Miami mafioso Meyer Lansky, who apparently was trying to build a casino in the Bahamas and was facing opposition from Oakes.

Some thought that the Duke of Windsor himself was involved in the murder. De Marigny said that Oakes, Edward, and others, primarily Harold Christie—a powerful businessman and realtor in the Bahamas—were involved in a conspiracy to smuggle money out of the commonwealth, possibly into Mexico. In one version of events, Oakes was trying to pull out of the dirty business and alert the authorities just before meeting his untimely demise.

Still others thought the money could be making its way to Nazi Germany—an outlandish theory, but not completely out of the realm of possibility, given Edward’s longstanding ties to Hitler and his regime. 

William Boyd, who wrote a fictionalized version of the case in his novel Any Human Heart, was convinced that Christie was responsible. Christie was staying in Oakes’s house the night of the murder and apparently owed his host a lot of money. He was even allegedly seen that night in town, despite his claims to have slept through the crime at Oakes’s home. 

Whether due to royal meddling or an incompetent investigation, though, we’ll probably never know all the facts about this high-profile crime.

 2. The Theft of a Bejeweled Cheese Slicer

If you find a diamond-encrusted cheese slicer and return it to Amsterdam’s Cheese Museum, your reward will include the world’s largest commercially available fondue set. Naturally. 

The platinum slicer was designed by jeweler Rodrigo Otazu for the cheese accessory outfitter Boska Holland. It contained 220 small diamonds and was valued at $26,000 when it was stolen in 2015. Though the culprits were caught on a security camera, they were never apprehended— and the slicer hasn’t been seen since.

 3. The Robbery of the Isabella Stewart Gardner Museum

When Isabella Stewart Gardner passed away, her will included a clause mandating that the fine art museum she had founded in Boston had to stay exactly the same. In fact, if anything inside were permanently changed, the will stipulated that the entire collection should be auctioned off, with the proceeds going to Harvard University. 

For more than 65 years, the museum granted her wish: All 2500 of the pieces in the collection remained in their exact places. But on March 18, 1990, that changed in a big way. In less than 90 minutes, two thieves went through the grounds and stole 13 works of art by the likes of Édouard Manet, Johannes Vermeer, Edgar Degas, and Rembrandt. You could call these artworks priceless, or you could say that they’d be worth around half a billion dollars today, according to one estimate. 

There have been decades of theories and more podcasts and documentaries about the heist than you can shake a stick at. The FBI reportedly identified suspects—who are now dead—but the art has never been recovered. To avoid having to auction off Gardner’s whole collection, the museum has chosen to display vacant frames where the artworks once hung. 

4. The Stolen Davidoff-Morini Stradivarius Violin

A different stolen Stradivarius, this one belonging to Roman Totenberg. It was missing for 35 years.
A different stolen Stradivarius, this one belonging to Roman Totenberg. It was missing for 35 years. / Andrew Burton/GettyImages

Erica Morini had some paintings stolen from her New York City apartment in October 1995, but they weren’t the most valuable items lost in the theft. Morini was a renowned musician, and the 1727 “Davidoff-Morini” Stradivarius violin taken from her home was worth millions of dollars. Morini, who had been in the hospital, died just days after the theft, evidently unaware that her prized instrument had been pilfered. The violin has never been found.

 5. The Murder of Giovanni Borgia

If you were a murderer in 15th-century Rome, the natural landscape of the city provided a handy means to dispose of evidence: the Tiber River. As local timber merchant Giorgio Schiavi put it at the time, “I have seen more than a hundred bodies thrown into the river … and never heard of anyone troubling himself about them.”

That changed with the death of Giovanni Borgia, the favorite son of Rodrigo Borgia, a.k.a. Pope Alexander VI. (If you think it’s a bit odd that a pope had children, well, Rodrigo wasn’t exactly a stickler for rules.) On the night of Giovanni’s disappearance, Schiavi, an innocent bystander, saw a body being thrown into the river.

After a couple days, with Giovanni’s disappearance causing a stir, Schiavi came forward with his account. The pope promptly ordered a search of the river and Giovanni’s body was found, riddled with stab wounds. He also had a coin purse on him with money inside it, likely ruling out a financial motive for the crime. 

Queen Isabella of Spain was supposedly one of many who believed Giovanni’s brother, Cesare, was behind the murder. The two Borgias had had a long-simmering sibling rivalry, perhaps stoked by professional jealousy. 

Their other brother, Gioffre, might also have had a motive: It was said that his wife Sancha was having an affair with Giovanni. (And perhaps with Cesare, too. Borgia family reunions were probably a bit complicated.) 

Still others point to a rival Italian family, the Orsini, as suspects. Killing Giovanni may have been a way of getting even after numerous interfamilial conflicts. Intriguingly, the pope’s investigation into his son’s death was abruptly cut off a few days after it started, leaving future generations to wonder why.

 6. The Death of Wilma Montesi

Centuries later, another powerful family was caught up in a sordid story with a tragic ending. Wilma Montesi was just 21 years old in 1953, the same year her body washed up on the shore just outside of Rome. Her death was ruled an accidental drowning by police, but questions soon started to swirl.

A journalist named Silvano Muto eventually accused a local aristocrat, Marchese Ugo Montagna, of heading a narcotics and prostitution ring that had led to Montesi’s tragic death. Montagna was said to have ties to the country’s Christian Democracy Party and to officials inside the Vatican. According to a 1954 issue of Time Magazine, when he threatened to break his silence, Montagna seemed to indicate how many people he could implicate in unsavory behavior, saying, “I may cause the end of the world.”

In the end, Montagna was acquitted of any wrongdoing, as was the police officer who had quickly wrapped up the initial investigation. Improbable as some in Italy found the explanation, the tragedy was once again deemed an accident.

 7. The Explosive Murder of Lord Darnley

Mary, Queen of Scots.
Mary, Queen of Scots. / Fine Art/GettyImages

When Lord Darnley, the king consort of Scotland, was killed in 1567, it would have been very hard to call it an accident. His assailants blew up the entire building he was staying in. And strangely, Darnley’s body was actually found outside the home—he was apparently killed by strangulation as he attempted to escape.

Many sources have pointed the finger at Darnley’s wife (who was also, incidentally, his cousin): Mary, Queen of Scots. The two had what seemed to be a troubled relationship. The writer Walter Scott later described Darnley as “remarkably tall and handsome,” but he was also apparently “destitute of sagacity, prudence … and exhibiting only doubtful courage.”

The queen may have been angered by her husband’s habit of carousing and womanizing. She probably also didn’t appreciate his possible role in the murder of David Rizzio, her private secretary and confidant. 

Many think that James Hepburn, the fourth Earl of Bothwell, organized the attack, but it’s unknown whether Mary was complicit in the crime, and it’s difficult to pin it on Bothwell definitively. Explosions have a way of destroying useful evidence, after all. 

If Mary did have a role in the attack, it didn’t end well for her. She was soon kidnapped by Bothwell and forced (according to most accounts) into an unwanted marriage with him. And in 1587, Mary had some further difficulties with a different cousin when Queen Elizabeth I of England had her beheaded.

 8. The Monster of Florence Case

You’re probably familiar with the story of the Zodiac killer, who may or may not have been a California man named Gary Poste. But what about the Monster of Florence? This serial killer (if, in fact, it was one person) was responsible for as many as 16 murders between 1974 and 1985, all in the hills near Florence, Italy. Each one of the victims was part of a couple evidently engaged in what the writer Douglas Preston called “a national pastime” in Italy: having sex in parked cars, away from the prying eyes of family members, whom Italians traditionally live with until they marry.

That lurid fact helped make the murders an irresistible subject for speculation in Florence; the grisly mutilations carried out by the Monster and the difficulty of homing in on a single suspect made it an enduring international story.

You can read plenty about the Monster of Florence online, including a long piece in The Atlantic, written by Preston, covering many of the investigation’s dead ends and suspicious missteps. But let’s focus on one strange aspect of the saga.

In 1981, crime correspondent Mario Spezi started reporting on a murder. He soon came to believe, like many, that the crime was just one in a series. Spezi even came up with the name il mostro de Firenze, or the Monster of Florence, for the unknown killer, perhaps in reference to the Monster of Dusseldorf, a killer who had terrorized that German city decades earlier.

Spezi’s reporting on the case often brought him into conflict with authorities. On multiple occasions, men suspected of the murders were jailed, and each time Spezi assiduously argued that police had the wrong man. And then, in 2006, Spezi himself was arrested, initially because of suspected ties to the murders, and eventually in relation to charges of obstruction.

Spezi spent more than three weeks in jail, including five days when he was prevented from talking to his lawyers. He believed it was retribution for the unflattering reporting he had given to some of the governmental figures involved in the investigation. A group of judges soon freed him.

When he was released from prison, Spezi vowed that his days writing about The Monster were done. And when asked about the case years later, Chief Inspector Michele Giuttari, who had locked horns with Spezi on multiple occasions (and who, oddly enough, also became a crime novelist), said, “The case will never truly be resolved … There are crimes which can never be properly investigated because certain powers, untouchables, will do anything to ensure cases do not go ahead.”

9. The Successful Hack of Washington, D.C.’s Naval Research Lab

In the year 2000, someone hacked Washington, D.C.’s Naval Research Lab and gained access to the source code for software in charge of missile and satellite guidance. Don’t worry, though: According to authorities, the thief only made off with two-thirds of the code, and some reports say it was an older version of the software, severely limiting the damage they could do. Government officials tracked the crime to a computer on the campus of a university in Germany, but if they ever got any further in their search, that information hasn’t been made public.

 10. The CBS News Website Hack

Though that story might not have been quite as dramatic as the “nuclear launch codes hacked” some headlines would suggest, it does point to the critical stakes around cybercrime and the potential it has to inflict massive damage on the world stage. 

And then there’s the time in 2003 that CBSNews.com was hacked in an effort to help the 10th-most-popular candidate in the Democratic presidential primary. That fall, as Ohio’s Dennis Kucinich languished in the polls, an intrepid Kucinich-head hacked into CBS News’s website so that visitors would be greeted by the Kucinich campaign logo and a 30-minute video featuring the candidate called “This is the Moment.” 

It was, apparently, not the moment. Kucinich dropped out of the race in July 2004.