The 20th century was rife with unsolved mysteries. Some remain subjects of intense debate to this day, such as the vanishing of Amelia Earhart, the mystery behind D.B. Cooper’s identity, and the infamous Black Dahlia murder. However, there are others that have slipped into obscurity, either forgotten by time or dismissed as having an 'unofficial' resolution that most people are willing to accept.
10. Did The Shotgun Man Really Exist?

At the turn of the 20th century, Chicago’s Little Sicily was a dangerous and volatile area for Italian immigrants. The Black Hand extortion syndicate held power over the community, forcing many into submission. For those who refused to comply, a figure known as the Shotgun Man would visit—an enforcer whose job was to intimidate and punish those who resisted the Black Hand.
The Shotgun Man became the terrifying figure of Little Sicily, lurking at the notorious intersection of Oak Street and Milton Avenue, known as 'Death Corner.' There, he would wait at the foot of a staircase, shotgun in hand, ready to strike. The moment his target appeared, he would fire and vanish before anyone could even comprehend what had just happened.
More than a century has passed since the Shotgun Man terrorized the streets of Chicago, yet his myth continues to grow. People now claim he murdered over 100 victims. He was so feared that he could stroll through the streets, weapon in hand, right after committing a killing, with no one daring to report him.
These claims are likely exaggerated, as is common with most legends over time. Some of the killings attributed to the Shotgun Man never took place. Others showed no real links to him. While crime was rampant in the city, there’s no evidence to support that all of it was the work of a single individual.
9. What Really Happened to Natalie Wood?

The tragic tale of actress Natalie Wood's untimely death has become widely known. On the night of November 28, 1981, Wood was on a boat called the Splendour, accompanied by her husband, Robert Wagner, her costar Christopher Walken, and the ship's captain, Dennis Davern.
The next morning, her lifeless body was discovered 1.6 kilometers (1 mile) away, next to a dinghy. She had a high blood alcohol concentration and had ingested several medications. The story told was that after an argument with her husband, Wood had taken the dinghy out and fallen overboard. Her death was officially ruled an accidental drowning.
While this remains common knowledge, many may not be aware that in 2012, the Los Angeles County coroner revised the cause of death to 'drowning and other undetermined factors.' This change followed the reopening of the case after three decades.
For years, rumors have circulated about Robert Wagner's possible involvement in his wife's death. After decades of silence, the ship's captain publicly stated that Wood’s death stemmed from a heated argument with Wagner. However, his claims were made in a new book, leading to allegations that he was exploiting Wood's tragic end for profit.
Following the re-investigation, the medical examiner concluded that some of the bruises found on Wood’s body likely appeared before she entered the water, although they couldn't be definitively linked. Her case remains open.
8. Who Was Behind the Murder of Bob Crane?

Bob Crane became famous for his role as the lead in the sitcom Hogan’s Heroes. In 1978, the 49-year-old actor was discovered bludgeoned to death in his apartment, with an electrical cord tightly wound around his neck.
While the actual murder weapon was never determined, the most probable one was a camera tripod. Police quickly turned their attention to John Henry Carpenter, a friend of Crane who was involved in selling video equipment. After Carpenter's death, it was revealed that Crane had a habit of picking up women and filming his sexual encounters, often with Carpenter participating. At the time of the murder, Carpenter had been visiting Crane, and blood stains were discovered in Carpenter’s rental car.
Initially, the prosecution hesitated to charge Carpenter due to lack of evidence. It wasn’t until 1992, when DNA testing became available, that Carpenter was formally charged with Crane’s murder. However, the DNA tests proved inconclusive, and the defense successfully argued that many others, including the women in Crane's films and their enraged partners, had reasons to kill him. Carpenter was acquitted, yet the public continued to view him with suspicion.
In 2016, things took a surprising turn when a news anchor successfully urged authorities to re-examine the case using advanced DNA testing. The results revealed that the blood on Carpenter’s rental car did not belong to Bob Crane. This new development left the actor’s son, Robert Crane Jr., visibly shocked. He then shifted his focus onto his stepmother, Patricia Olson, who was the sole heir to Crane’s estate.
7. What Happened Aboard the Carroll A. Deering?

Nearly a century has passed since the five-masted schooner Carroll A. Deering ran aground on Diamond Shoals near Cape Hatteras. Known as the “Graveyard of the Atlantic,” Cape Hatteras had claimed its share of sunken ships. Yet the Deering was found in perfect condition, except for the disappearance of its crew.
The schooner was first spotted on January 31, 1921. However, adverse weather conditions prevented authorities from reaching it for four days. When they finally boarded the vessel, they discovered that the entire crew had vanished, leaving behind their personal belongings, ship’s log, navigation tools, and two lifeboats.
The site where the schooner had run aground became its final resting place. Since the Deering posed a danger to passing ships, it was eventually scuttled and destroyed by dynamite.
Several investigations were launched to uncover what happened to the crew. Some speculated that mutiny had occurred, others believed that the ship had been seized by rum smugglers from the Bahamas. Another theory suggested that the crew abandoned ship to escape an impending hurricane.
A popular theory among anti-communist groups of the era suggested that Bolsheviks were responsible for targeting U.S. ships. Given the crew’s disappearance near the Bermuda Triangle, some people even proposed supernatural explanations for their vanishing.
The investigation was officially closed in 1922 without reaching a definitive conclusion. Despite thorough searches, the crew of the Carroll A. Deering was never found.
6. What Happened to the Lady of the Swamp?

Margaret Clement’s father began his life as a cattle farmer in Scotland, but eventually found success through mining investments in Australia. By the time of his death in 1890, he had left a significant fortune to his widow and five children.
Margaret spent the first portion of her life in comfort and luxury. Two of her sisters married and started their own lives. In 1907, Margaret, along with her sister Jeanie and their brother Peter, purchased the grand Tullaree Mansion in Gippsland. The house was beautiful, but it was surrounded by rough and swampy land.
When Peter married and left in 1912, Margaret and Jeanie discovered they lacked the skills to successfully manage the farm. By the 1920s, a series of poor decisions put the sisters in financial turmoil, and they withdrew from society, becoming recluses.
It wasn’t until 1950, when Jeanie passed away, that the public realized just how far the Clements had fallen. Tullaree Mansion had become a shadow of its former self—crumbling, without basic utilities, and engulfed by thick, overgrown foliage. Rumors spread about the peculiar old woman who spent her days reading mystery novels by lamplight, accompanied only by her dog, Dingo. Margaret became known as the 'Lady of the Swamp.'
In 1952, the Lady of the Swamp mysteriously vanished. Suspicions arose about her neighbors, Stanley and Esme Livingstone, while others pointed to Margaret’s nephew, Clement Carnaghan, who had been disinherited shortly before her disappearance.
Some speculated that the old woman fell victim to the dangers lurking in the swamp. Others believed that Margaret may have taken her own life elsewhere, trying to create a dramatic ending worthy of the mystery novels she loved so much.
5. How Did Eugene Izzi Die?

Eugene Izzi had a notable career as a writer of gritty detective stories set against the backdrop of his hometown, Chicago. However, the most enduring mystery he left behind was the question of his premature death.
Izzi's body was discovered on December 7, 1996, hanging outside his 14th-floor office in downtown Chicago. The rope was tied to a steel desk in his office. At first, it appeared to be a clear case of suicide, which was the official conclusion. However, the circumstances surrounding his death seemed more like a plot from one of his own mystery novels.
One major problem with the suicide theory was the absence of any clear motive. Friends and family couldn't fathom why Izzi would take his own life, especially with a new book set to be released. Even stranger, the writer was found wearing a bulletproof vest. In his pockets, police discovered brass knuckles and mace. Reports also indicated that a .38-caliber revolver was found in his office.
Was there a reason for Izzi to fear for his safety? Friends claimed that he had infiltrated a paramilitary group in Indiana as part of his research for a new book. He had even received a threatening voicemail. This theory was bolstered by an article submitted to the Chicago Sun-Times in which Izzi criticized militias and hate groups.
4. Who Was The Zodiac Killer?

The Zodiac Killer remains one of the most notorious serial killers in history, mainly because his true identity has never been uncovered. Many have speculated that Arthur Leigh Allen could be the Zodiac, but this theory has been the subject of debate.
However, there are numerous pieces of evidence that cast doubt on Allen being the killer. He didn’t match the composite sketch, his handwriting didn’t match the cryptic letters sent to authorities, and his DNA didn’t match the partial profile extracted from the envelopes.
After nearly four decades, the case had gone cold before being officially reopened around 2007. In the years that followed, investigators considered a number of new suspects in an attempt to solve the mystery.
Three men came forward, each claiming their fathers were the infamous Zodiac Killer. Among them was retired detective Steve Hodel, who had previously suggested that his father, George Hill Hodel Jr., was behind the Black Dahlia murder.
Two other individuals have come forward claiming they received confessions regarding the Zodiac killings. One of them, lawyer Robert Tarbox, recalled a sailor walking into his office in the 1970s and admitting to being the Zodiac. Tarbox kept this information private for 30 years due to confidentiality agreements. Another man, Randy Kenney, said his friend Louie Myers confessed to being the Zodiac on his deathbed.
Retired highway patrol officer Lyndon Lafferty also presented a potential suspect. Lafferty was part of a group of former officers turned amateur investigators known as the Mandamus Seven.
The group identified the Zodiac as a former real estate agent from Fairfield, California, who passed away in 2012. They introduced him under the alias George Russell Tucker. According to the Mandamus Seven, there was a conspiracy behind the investigation, claiming that Tucker’s wife had an affair with a judge who distracted the investigation.
3. What Happened To Dorothy Arnold?

On the morning of December 12, 1910, 24-year-old socialite Dorothy Arnold from New York ventured out to shop. She spent some time wandering Fifth Avenue before running into her friend Gladys King. As they parted ways, King recalled that Arnold planned to stroll through Central Park. She was the last person to see Dorothy Arnold.
By the evening, the Arnold family grew concerned and realized something was amiss. Seeking to keep the situation private, they turned to their lawyer, John Keith, for help. Keith suggested they hire Pinkerton detectives to discreetly investigate Dorothy's disappearance.
The investigation led detectives to visit Arnold’s familiar spots. They checked local hospitals, jails, morgues, and even insane asylums but found no trace of Dorothy. Some detectives even speculated that she may have run off with a secret lover to Europe. Pinkerton detectives traveled overseas but came up empty-handed.
The Arnolds were aware of Dorothy’s relationship with George Griscom Jr., whom they disapproved of. At the time of Dorothy’s disappearance, Griscom was vacationing with his family in Florence. The Arnolds visited him, but found no clues regarding their daughter’s whereabouts. After six weeks without any progress, they reluctantly contacted the police and, even more hesitantly, informed the public, offering a $1,000 reward.
Two ransom notes were quickly dismissed as hoaxes. So was a postcard supposedly written by Dorothy herself. Some speculated that Dorothy had taken her own life, possibly due to her secret relationship with Griscom or the failure of her writing career.
Her father believed that she had been murdered in Central Park and her body discarded in the water reservoir. A convict even came forward, claiming to have been paid to dispose of a body matching Dorothy Arnold’s description.
One widely circulated theory suggested that Dorothy had died from complications after an illegal abortion, and that her body had been cremated to cover up the evidence. Many leads were followed up, but none provided any substantial breakthrough in the case.
2. How Did Marvin Clark Disappear?

Marvin Clark, born in 1851, vanished in 1926 from Portland. He holds the grim distinction of being the longest-active missing persons case in the U.S. Clark disappeared during Halloween weekend after leaving his home in Tigard, Oregon, to visit his daughter, who ran the Hereford Hotel in Portland.
At first, newspapers reported that Clark had traveled to Portland by stagecoach and disappeared during or after the ride. This story was later corrected to say that he had traveled by bus and was last seen getting off at the Portland terminal.
Over the years, there were several unconfirmed sightings of Clark. However, the first solid lead didn’t emerge until 1986, when a John Doe was found in the woods between Tigard and Portland. The man had a few belongings typical for the time, as well as a revolver with a spent shell casing. A bullet hole in his skull led investigators to conclude that his death was a suicide.
Clark’s granddaughter, Dorothy Willoughby, later came forward, suggesting that the John Doe could be her grandfather. Unfortunately, no positive identification could be made at the time.
Willoughby passed away in 1991, and the case went cold again. It wasn’t until 2011 that the investigation was reopened. By then, a good sample had been extracted from the skeleton, and genealogists began searching DNA databases to find potential maternal relatives of Clark for comparison.
1. What Happened To The Girl In The Green Mac?

On August 18, 1944, six-year-old Sheila Fox was walking home from school in Bolton, Lancashire. However, she never made it home that night. Despite extensive search efforts by police and volunteers, no trace of Sheila was found. Witnesses reported that she was last seen with a young man, approximately in his mid to late twenties, well-dressed, clean-shaven, and of slim build.
The media came to refer to Sheila as the 'Girl in the Green Mac.' Although her disappearance was initially eclipsed by the events of wartime, the mystery surrounding it remained unresolved. The search was reignited 57 years later.
The renewed investigation was sparked by a tip-off from someone who remembered seeing a neighbor digging a hole in his garden on the night Sheila vanished. A quick look into the history of the house revealed that in 1944, it was occupied by 20-year-old Richard Ryan, who would later be convicted for rape and charged with child assault in separate cases.
Despite the intriguing lead, investigators found nothing in Ryan’s old garden. Some tried to link Fox's disappearance to other similar child disappearances from the same time period, speculating that they might have been the work of a single individual. However, no solid leads have yet emerged.
