12 Serial killers who were never caught 2023

Some of the most infamous serial killers in American history were eventually identified through fingerprints, confessions, DNA evidence, or mistakes that finally led investigators to them.

Others simply disappeared.

Across the United States, investigators are still dealing with serial murder cases in which no perpetrator was ever successfully prosecuted—and in many cases, the killer's identity remains completely unknown.

Some of these mysteries are nearly a century old. Others remain active cold cases in which investigators hope modern DNA testing and forensic genealogy could finally produce an answer.

It is important to clarify what “serial killers who were never caught” means here. It does not necessarily mean each offender is still alive or walking free. In several cases, investigators developed strong suspects who later died. In others, authorities cannot even say with certainty whether every murder attributed to the same nickname was committed by one person.

What connects these cases is simpler: nobody has ever been convicted of the serial murders themselves.

From the Zodiac Killer to the Freeway Phantom, these are 12 American serial killers—and suspected serial murderers—who escaped justice.

1. The Zodiac Killer

Few unidentified serial killers have generated more fascination than the Zodiac Killer.

Between 1968 and 1969, a killer attacked several people in Northern California. Five victims are generally recognized as confirmed murder victims, while two others survived.

But the murders were only part of what made the case extraordinary.

Someone claiming to be the killer began sending letters to Bay Area newspapers. The writer called himself “Zodiac,” supplied information intended to demonstrate knowledge of the crimes, and included cryptograms that challenged authorities and the public to decipher his messages.

One of the most famous, the 340-character cipher, remained unsolved for more than 50 years before an independent team decoded it in 2020. The solution revealed another disturbing message—but not the killer's identity.

Dozens of people have been proposed as possible Zodiac suspects over the decades. Arthur Leigh Allen became the most famous, but no publicly established forensic evidence has ever proved he was Zodiac.

Claims that investigators have finally identified the killer periodically make headlines, but authorities have not officially confirmed any of them. The FBI has continued to describe its Zodiac investigation as open and unsolved.

More than half a century after the murders, the identity of the Zodiac Killer remains one of the greatest mysteries in American true crime.

2. The Freeway Phantom

Between April 1971 and September 1972, six young Black girls and young women disappeared from Washington, D.C.

They were Carol Spinks, Darlenia Johnson, Brenda Crockett, Nenomoshia Yates, Brenda Woodard and Diane Williams.

Their bodies were later discovered in Washington, D.C., or nearby Prince George's County, Maryland.

The unknown offender became known as the Freeway Phantom.

The case contained several unusual pieces of evidence. Twelve-year-old Brenda Crockett reportedly managed to telephone her family while she was missing, telling them that a white man had abducted her. Another victim, Brenda Woodard, was found with a note apparently dictated or written by the killer.

Despite an enormous investigation and numerous suspects, no one was successfully prosecuted for the murders.

The Metropolitan Police Department still lists the Freeway Phantom victims among its major unsolved homicide cases and continues to seek information concerning the person or persons responsible.

The case also represents an important chapter in true-crime history because the victims were Black girls whose murders never received the lasting national attention given to several other famous serial-killer investigations.

More than five decades later, the Freeway Phantom murders remain unsolved.

3. The Oakland County Child Killer

Michigan was gripped by fear during 1976 and 1977 after four children disappeared from communities in Oakland County outside Detroit.

The confirmed victims were Mark Stebbins, Jill Robinson, Kristine Mihelich and Timothy King.

The children were between 10 and 12 years old.

Their disappearances contained disturbing similarities. Investigators determined that some of the victims had apparently been held captive for a period before being killed. Their bodies were later deliberately left in locations where they could be discovered.

The unknown offender became known as the Oakland County Child Killer, or OCCK.

The investigation grew into one of the largest manhunts in Michigan history. Police examined thousands of tips and investigated numerous suspects and possible connections.

Yet no one was convicted.

The case has produced decades of arguments involving potential suspects, DNA evidence, alleged links to other crimes and accusations concerning how the original investigation was handled.

What remains undisputed is that the four murders have never been solved.

Michigan State Police confirmed in 2026 that the investigation remains open and that new information continues to be examined.

Nearly 50 years after the first child disappeared, the Oakland County Child Killer remains unidentified.

4. The West Mesa Bone Collector

One of the most disturbing unsolved serial murder investigations in modern American history began with a discovery in Albuquerque, New Mexico.

In February 2009, human remains were discovered on Albuquerque's West Mesa.

Investigators eventually recovered the remains of 11 women and an unborn child.

Most of the women had disappeared between approximately 2001 and 2005.

Investigators came to believe that someone had been using the remote area as a burial ground. The unknown offender became widely known as the West Mesa Bone Collector.

Several potential suspects have received attention over the years, but investigators have never gathered enough evidence to prosecute anyone for the murders.

The possibility that additional missing women could be connected to the case has also remained part of the investigation.

Unlike many historical cases on this list, the West Mesa murders remain an active modern cold case.

In February 2026, Albuquerque officials marked the 17th anniversary of the discovery and confirmed that the murders remain unsolved and that police continue seeking information about those responsible.

The identity of the West Mesa Bone Collector remains unknown.

5. The Cleveland Torso Murderer

During the Great Depression, Cleveland became the hunting ground of one of America's most disturbing unidentified killers.

Between 1935 and 1938, dismembered human remains were repeatedly discovered in and around the city's Kingsbury Run area.

At least a dozen victims are generally associated with the murders, although investigators and researchers have debated whether additional deaths may have been connected.

Many victims lived on the margins of society, and several were never identified.

The killer became known as the Cleveland Torso Murderer or the Mad Butcher of Kingsbury Run.

The case attracted national attention partly because Cleveland's Public Safety Director at the time was Eliot Ness, already famous for his role in pursuing organized crime during Prohibition.

Ness and other investigators pursued numerous leads.

One particularly intriguing suspect was Dr. Francis Sweeney, a physician who reportedly came under intense scrutiny. Ness apparently believed Sweeney may have been responsible, but investigators never obtained evidence sufficient to prosecute him.

No definitive identification was ever made.

Case Western Reserve University's Encyclopedia of Cleveland History describes the murderer's identity as undiscovered despite the enormous investigation.

Modern efforts have even turned toward DNA and forensic genealogy in hopes of identifying some of the unknown victims.

But the central question remains unanswered:

Who was the Cleveland Torso Murderer?

6. The Axeman of New Orleans

Between 1918 and 1919, residents of New Orleans faced a series of mysterious nighttime attacks committed by an unknown intruder.

Many victims were Italian immigrants or Italian-American shopkeepers and their families.

The attacker frequently entered homes and used an axe or similar weapon—sometimes apparently using a weapon found inside the victim's own home.

The murderer became known as the Axeman of New Orleans.

Then the case became even stranger.

In March 1919, New Orleans newspapers received a letter supposedly written by the Axeman. The writer claimed another attack would occur on a particular night but said anyone in a home where jazz music was being played would be spared.

New Orleans responded.

Jazz reportedly filled homes, restaurants and dance halls across the city.

No Axeman murder occurred that night.

Whether the letter actually came from the murderer has never been conclusively proven, but it became one of the most famous episodes in the history of the case.

The attacks eventually stopped just as mysteriously as they began.

No one was ever definitively identified as the Axeman, and the murders remain unsolved.

More than a century later, the Axeman of New Orleans remains one of America's oldest unidentified serial killers.

7. The Alphabet Murders

Three child murders in the Rochester, New York, area during the early 1970s became known as the Alphabet Murders or Double Initial Murders.

The victims were:

Carmen Colón.

Wanda Walkowicz.

Michelle Maenza.

All three were young girls whose first and last names began with the same letter.

Another strange coincidence emerged from the locations where their bodies were found: Carmen near Churchville, Wanda near Webster and Michelle near Macedon.

Those patterns helped create the name “Alphabet Murders.”

However, an important distinction is often lost when the story is retold.

The similarities caused the murders to become linked in the public imagination, but it has never been conclusively established that one person committed all three crimes.

Investigators examined hundreds of potential suspects and several individuals became the focus of theories over the decades.

None resulted in a conviction.

The murders of Carmen Colón, Wanda Walkowicz and Michelle Maenza remain unsolved.

Whether the Alphabet Killer was one murderer, multiple offenders or simply a terrifying coincidence remains one of the central unanswered questions surrounding the case.

8. The New Bedford Highway Killer

Beginning in 1988, women associated with the New Bedford, Massachusetts, area began disappearing.

Eventually, the bodies of nine women were discovered along highways and roads in southeastern Massachusetts.

Two other missing women have also long been considered possible victims.

The suspected murderer became known as the New Bedford Highway Killer.

Many of the victims knew one another or moved within overlapping social circles. Several struggled with addiction, and some were involved in sex work—circumstances that may have made their disappearances easier for a predator to exploit.

Investigators developed multiple suspects.

Attorney Kenneth Ponte was even indicted in connection with one victim's death in 1990, but prosecutors later dropped the charge because of insufficient evidence. He was never convicted of one of the highway murders.

Decades later, investigators have continued examining forensic evidence and potential DNA connections.

No one has been successfully prosecuted for the killing series, however, and the investigation remains unresolved.

The New Bedford Highway Killer therefore remains one of New England's most disturbing unsolved serial murder mysteries.

9. The I-70 Killer

For less than a month during the spring of 1992, someone walked into small retail businesses across the Midwest and murdered employees.

The attacks occurred in Indiana, Kansas and Missouri, many near Interstate 70.

Investigators linked six murders through ballistics.

Most victims were young women working alone inside small specialty stores. The exception was Michael McCown, who investigators have theorized may have been mistaken for a woman when the killer observed the business from outside.

Witnesses provided descriptions of the suspect.

Police developed composite sketches.

Investigators knew that the same firearm had been used.

And yet the murderer vanished.

The unidentified offender became known as the I-70 Killer.

Investigators have also examined whether similar shootings in Texas during the following years—and possibly a later murder in Indiana—could have involved the same person.

Those additional connections remain less certain than the original six murders.

Authorities were still publicly pursuing the I-70 Killer case decades later, and no perpetrator has been identified.

The killer managed to leave eyewitnesses, ballistic evidence and a multi-state trail behind—and still escaped capture.

10. The Honolulu Strangler

Between 1985 and 1986, five women were murdered on the Hawaiian island of Oahu.

They were Vicki Purdy, Regina Sakamoto, Denise Hughes, Louise Medeiros and Linda Pesce.

Similarities between the murders led authorities to believe the same offender may have been responsible.

The killer became known as the Honolulu Strangler.

Police eventually focused heavily on one suspect, Howard Gay.

Gay reportedly came to investigators' attention after the final murder and was questioned, but authorities lacked sufficient evidence to charge him.

He was released.

Gay later moved away from Hawaii and died in 2003.

Whether he actually was the Honolulu Strangler has never been proven.

The five murders therefore remain officially unresolved, and no one was ever prosecuted for the killing series.

The Honolulu Strangler case demonstrates an important distinction in many unsolved serial murder investigations: having a strong suspect is not the same as solving the case.

Without sufficient evidence, a theory remains only a theory.

11. The Phantom Killer of Texarkana

In 1946, a series of nighttime attacks terrorized the Texarkana area along the Texas-Arkansas border.

The crimes became known as the Texarkana Moonlight Murders.

Over roughly ten weeks, eight people were attacked and five were killed.

Several attacks targeted couples parked in secluded areas.

Survivors of the first attack described a masked attacker, helping create the frightening public image of an unknown murderer stalking the region.

Newspapers eventually began calling the assailant the Phantom Killer.

Police launched an enormous investigation.

One man, Youell Swinney, became a particularly significant suspect, and some investigators apparently believed he was responsible.

But Swinney was never convicted of the Phantom murders.

The attacks stopped in May 1946.

No definitive explanation ever followed.

The Encyclopedia of Arkansas still describes the identity of the Phantom Killer as unknown and the murders as an unsolved cold case.

The story later inspired The Town That Dreaded Sundown, helping transform a real unsolved murder series into one of America's most enduring true-crime legends.

12. The Servant Girl Annihilator

Before Jack the Ripper terrorized London, another unidentified murderer was attacking people thousands of miles away in Austin, Texas.

Between December 1884 and December 1885, a series of nighttime attacks left eight people dead.

Many of the earliest victims were Black women working as domestic servants.

The unknown murderer eventually became known as the Servant Girl Annihilator, a nickname associated with writer O. Henry, who was living in Austin during the period.

Victims were attacked in or near their homes, frequently during the night.

The killings triggered panic throughout the rapidly growing city.

Police arrested and investigated numerous people, but the investigative techniques available during the 1880s were extremely limited compared with modern forensic methods.

One later theory has focused on Nathan Elgin, a young cook who died after being shot by police in 1886. Researchers have pointed to circumstantial details that could make him a possible suspect.

There is no definitive evidence proving he committed the murders.

The Travis County Archives describes the killer as having eluded police, private investigators and civilians, with the crimes remaining unsolved.

The Servant Girl Annihilator is sometimes described as one of the earliest known serial killers in American history.

His identity has never been established.

How Do Serial Killers Avoid Being Caught?

Looking across these cases reveals how much homicide investigations have changed.

The oldest murders occurred before investigators had access to DNA analysis, computerized databases, modern fingerprint systems, surveillance cameras, cell-phone records or the ability to quickly compare crimes occurring hundreds of miles apart.

Other investigations suffered because victims came from marginalized communities whose disappearances did not always receive immediate attention.

Geography also mattered.

A murderer who crossed police jurisdictions could take advantage of agencies that did not routinely share information with one another.

And sometimes investigators came remarkably close.

Several cases on this list produced compelling suspects. But suspicion is not enough to establish guilt. Without evidence capable of surviving scrutiny in court, investigators cannot legitimately declare a murder solved.

That is why some suspects died with the question still hanging over them.

Can DNA Finally Identify America's Uncaught Serial Killers?

There is more reason for optimism today than there was even a decade ago.

Investigative genetic genealogy has transformed cold-case investigations by allowing investigators in some circumstances to compare unidentified DNA with relatives found through genealogy databases.

The technology has already demonstrated that decades-old serial murder investigations are not necessarily beyond solving.

But DNA is not a magic solution.

Evidence must still exist. It must have been preserved well enough to test, and investigators must be able to establish that the genetic material actually came from the offender rather than a victim, investigator or unrelated person.

Cases from the nineteenth and early twentieth centuries may have very little usable evidence left.

More recent cases potentially have better odds.

That means killers who once seemed destined to remain anonymous may not stay anonymous forever.

Was the Long Island Serial Killer Ever Caught?

Yes—which is why the Long Island Serial Killer no longer belongs on lists of serial killers who were never caught.

Rex Heuermann was arrested in 2023 as part of the Gilgo Beach investigation.

The case continued expanding afterward.

In April 2026, Heuermann pleaded guilty to seven charged murders and publicly admitted killing an eighth victim, Karen Vergata. In June 2026, he was sentenced to three consecutive life sentences plus an additional 100 years.

His identification demonstrates exactly why articles about unsolved serial killers need regular updating.

A case can remain cold for decades—and then suddenly change.

Is the Smiley Face Killer Real?

The so-called Smiley Face Killer is better described as the Smiley Face murder theory.

The theory proposes that numerous deaths of young men found in bodies of water may actually represent murders committed by one or more killers.

However, investigators have never established such a connection.

The FBI has said it found no evidence linking the deaths or substantiating the theory that they were the work of a serial killer or group of killers.

For that reason, the Smiley Face theory should be discussed separately rather than presented alongside confirmed serial murder investigations as though its premise were established fact.

Serial Killers Who Vanished Without Justice

The most unsettling part of these cases is not simply that they are unsolved.

It is how close investigators sometimes came.

Witnesses saw suspects. Police questioned possible offenders. Letters were preserved. Weapons were compared. DNA was collected. Thousands of tips were investigated.

And still, nobody was convicted.

Some of these mysteries may never be solved. The perpetrators of the oldest crimes almost certainly died decades ago, and crucial evidence may have disappeared with them.

Others still have a chance.

Cases such as the West Mesa murders, Oakland County Child Killer investigation and other modern cold cases continue to benefit from advances in DNA testing, forensic genealogy and digital investigative techniques.

History has repeatedly shown that “unsolved” does not necessarily mean unsolvable.

For the families of the victims, that distinction matters far more than the mystery surrounding the killers themselves.