20 of the Most Notorious Unsolved Serial Killings in History

Michael Rosen

Last week we talked about the most prolific serial killers in United States history but there were a few prolific serial killers left off the list. The reason for that was simple – as terrifying as it is, the serial killers left off the list were left off because their identities are still unknown. Some of the other unknown serial killers on this list aren’t believed to have been quite as prolific as the killers we talked about earlier but in truth, it’s a little hard to say for certain. Some of these killings may be the work of the same serial killer or of another killer already convicted of a crime. All the same, the very fact that the serial killers either could still be out there victimizing innocent people or went to their grave without facing justice is truly disturbing, to say the least. Because of space restraints, I haven’t really discussed the specifics in these serial killer cases but there is a link after each entry on the list that will take you to the Wikipedia page for the crime. There you can learn more about the crimes, the suspects and the cases in general.

20: The Alphabet Killer

Location: Rochester, New York
Active: 1971-1973
Known Victims: 3
Survivors: No known survivors
Suspects: Kenneth Bianchi (The Hillside Strangler, along with his cousin, Angelo Buono), Joseph Naso
Based on circumstantial evidence, it appears this one no longer remains unsolved as Joseph Naso seems like the most likely culprit. Despite this fact, no concrete evidence has tied Naso to the crimes and he has not been charged with these murders so technically it remains unsolved. I included this one on the list because, to me, it’s one of the most frightening unsolved serial murders in history. This killer seems to target only people with double initials, meaning their first name and their last name start with the same letter. It’s disturbing to think his victims may only have been killed because of their names.

19: The Oakland Child Killer

Location: Oakland County, Michigan
Active: 1976-1977
Known Victims: 4 (believed to be more)
Survivors: no known survivors
Suspects: Ted Lamborgine, Chris Busch, John Wayne Gacy
While there are only four known victims of the Oakland Child Killer, the fact that the targets were children makes this case especially disturbing. Add to that the fact that there is possibly a John Wayne Gacy connection (linked by circumstantial evidence only) makes it even worse because if the children in Oakland were killed by Gacy or killed by someone connected Gacy, it’s hard to say how high the body count actually was. There is something especially disturbing about someone that victimizes innocent children, even more so when that someone is never brought to justice.

18: Jack the Ripper

Location: Whitechapel, London
Active: 1888
Known Victims: 5
Signature: no known survivors
Suspects: many suspects supported by circumstantial evidence and unproven theories
Jack the Ripper is probably the most famous unknown serial killer in history. Everyone even remotely familiar with the case has their theories about who did it but no one was ever brought to justice and this long after the fact, no one ever will be. The real person responsible for this crime died long ago, going to his (or, based on recent speculation, her) grave knowing he got away with some of the most vicious, twisted murders in history.

17: The Phantom Killer

Location: Arkansas, Texas
Active: February 22, 1946-May 3, 1946
Known Victims: 5
Survivors: 3
The Phantom Killer took five lives between February and May of 1946 and injured three more people before the known killings linked to him stopped. Some believe the Phantom Killer and the Zodiac Killer, who we’ll be talking about in a moment, are one in the same based on circumstantial evidence and the similar style of the crimes but a definitive link has not been proven as of yet. If this is the work of The Zodiac Killer, the body count would be at least ten (maybe closer to 50) and the killings would be spread across three, maybe four, states. That is certainly frightening but whether or not it’s more frightening than a separate unknown serial killer is kind of a toss up.

16: The Zodiac Killer

Location: Various locations in California (possibly extending to Nevada)
Active: late 1960s early 1970s
Known Victims: 5 (killer confessed to 37 murders in letters but there is currently no evidence to support the confession)
Survivors: 2
Suspects: Arthur Leigh Allen, Don Cheney
Lots of people have lots of theories on who the Zodiac Killer is so, if you believe the Zodiac Killer and The Phantom Killer are the same person, lots of people have lots of theories on who The Phantom Killer is as well. It’s hard to say for certain if anyone has gotten it right yet but it is certain that no one has ever been convicted of the Zodiac Killer’s crimes leaving a lot of families without answers or justice. If the Zodiac Killer interests you, I’d highly recommend checking out the film Zodiac starring Jake Gyllenhaal and Robert Downey Jr. among others. It’s an interesting look at the story, based on the true crime novel of the same name.

15: The Freeway Phantom

Location: Washington, D.C.
Active: April 1971-September 1972
Known Victims: 6
Survivors: no known survivors
Suspects: Robert Elwood Askins
The Freeway Phantom kidnapped, raped and strangled six young African American girls between April 1971 and September 1972 but despite credible suspects, no one has ever been convicted of the murders. Perhaps the most viable suspect was Robert Elwood Askins, a man responsible for multiple murders but who denied having any involvement in the murders attributed to the Freeway Phantom. Many have viewed this denial with great skepticism considering Askins was in prison for two abductions and rapes committed around the same time when he died at age 91 but no concrete evidence was ever uncovered to tie Askins to the Freeway Phanton slayings. Despite the fact that many connected to the case believe Askins was responsible for the murders, the case remains open as a cold case.

14: Jack the Stripper

Location: London
Active: 1964-1965
Known Victims: 6 (two other murders may be the work of Jack the Stripper but this has not been proven)
Survivors: no known survivors
Suspects: Mungo Ireland, Freddie Mills, DC Brian Cushway, Tommy Butler, Harold Jones
While researching this article, I looked up several articles about unsolved serial killings and found Jack the Stripped mentioned numerous times. Each article he was mentioned in inevitably drew comments about the hilarious ‘Stripper’ typo so I want to be clear. That is not a typo. There was Jack the Ripper (whom we’ve already talked about) and Jack the Stripper – two separate serial killers, both of them remain unknown to this day. A concrete number of victims on this one is difficult to determine because there are at least two other murders investigators believe should be attributed to the Stripper but that lack the concrete evidence to connect the crimes definitively. In any event, there have been many possible suspects tied to this crime but no one has ever been convicted in the slayings and the case therefore remains unsolved.

13: The Tylenol Murders

Location: Chicago
Active: September-October 1982
Known Victims: 7
Survivors: no known survivors although it would be difficult to determine due to the nature of the killings
Suspects: James William Lewis, Ted Kaczynski (The Unabomber)
This is one of the most perplexing and frightening unsolved serial killings on this list for me simply because it really is random in the truest sense of the word. There were no intended targets here aside from innocent people with general aches and pains. Perhaps the most disturbing part of the story lies in the fact that the death toll likely would’ve been much higher has authorities not figured out the deaths were linked to tainted Tylenol. While there have been several strong suspects in the case, no one has ever been convicted of this rash of poisonings – crimes that led to the introduction of the tamper-proof containers we’re now so familiar with.

12: The Axeman of New Orleans

Location: New Orleans, Louisiana and surrounding communities
Active: May 1918-October 1919
Known Victims: 8 (number is thought to be higher)
Survivors: at least three survivors, possibly more
Suspects: several possible suspects have been put forth but no one has been convicted of the murders
There are lots of disturbing things at work in this story. Most obviously, of course, is the killer himself. As the name he was given implies, he used an ax to kill his victims, often using an ax he found in or around the victim’s home. Via various correspondences with the press and with the authorities, the killer showed no remorse at all for his crimes, even penning a letter promising to kill someone at an exact date and time at any home not hosting a live jazz band. When that date and time came, most homes throughout New Orleans hosted jazz bands and by the time morning rolled around, the Axeman had not claimed any new victims.

11: The Servant Girl Annihilator

Location: Austin, Texas
Active: 1884-1885
Known Victims: 8
Survivors: 8 survivors, possibly more
Suspects: as many as 400 suspects were arrested but only one was charged and convicted, a conviction that was later overturned
There has been speculation that murders attributed to the Servant Girl Annihilator were actually the first murders committed by Jack the Ripper. Evidence of this theory is extremely circumstantial but has proved intriguing and certainly isn’t beyond the realm of possibility. What we know for sure though is that these crimes were carried out by a very disturbed individual who seemed to choose a very specific kind of victim, African American women who worked as servants. While some of the murders attributed to him didn’t seem to fit that victim description – two young white women and one black man were killed by the Annihilator – the majority of his victims did. This has fed the Jack the Ripper theory. At the time, servant women were treated without about the same respect prostitutes would’ve been offered in White Chapel during the Ripper murders. Of course, all of the Rippers known victims were white but so too were the Annihilator’s last two known victims. Some true crime authors believe at least one of the leading suspects in the Ripper murders, James Maybrick, may have been in Texas at the time of the Annihilator murders. This has never been proven though and the actual connection remains more speculation than fact.

10: The New Bedford Highway Killer

Location: New Bedford, Massachusettes
Active: July 1988-June 1989
Known Victims: 9
Survivors: Two potential survivors or two potential victims
Suspects: Anthony DeGrazia, Kenneth C. Ponte, Daniel Tavares Jr.
The New Bedford Highway Killer took the lives of at least nine known prostitutes or substance abusers before his reign of terror came to a sudden end. Why did he stop killing? Is it possible he went to prison for another crime? Is it possible he was killed or committed suicide? Is it possible he moved to another state and continued his killing there? It’s impossible to say – unless, of course, you believe the killings were the work of Daniel Tavares Jr, a convicted killer who indirectly claimed responsibility for the slayings in a letter to a prison staff member while he was incarcerated for murdering his mother. He pointed authorities in the direction of a body of a woman who had been buried less than a mile from his house but it is not known if she was also a victim of the New Bedford Highway Killer and all of the other evidence tying Tavares to the murders is purely circumstantial. Two women who went missing around the time the murders took place are believed to have been abducted by the New Bedford Highway Killer but their bodies have never been recovered.

09: Hwaseong Serial Murders

Location: Hwaseong, South Korea
Active: September 15, 1986-April 3, 1991
Known Victims: 10
Survivors: no known survivors
Suspects: 21, 280 individuals were considered suspects but no one was ever charged with the murders
This unsolved serial murder has the distinction of being one of the first crimes of its kind in South Korea. While there had previously been active serial killers in the area, none had used the method of operation from event to event. This one was different. In Hwaseong, authorities were faced with something they’d never been faced with before – a killer who had gagged, raped and strangled ten women, often using the woman’s own pantyhose or socks as the weapon that killed them. An estimated two million police officers were called in to investigate – the largest number of officers ever assigned to a case at the time – and despite having 21,280 suspects, no one was ever convicted. The statute of limitations has now run out on the murders but police have kept the files due to the nature of the crimes.

08: The Gilgo Beach Killer

Location: Long Island, New York
Active: unknown
Known Victims: 10 (4 more murders believed to be linked to this killer)
Survivors: no known survivors
Suspects: Joel Rifkin was believed to have been responsible for some of the older remains uncovered but he has denied involvement.
This one is puzzling case for a number of reasons. First, no one can really be sure how long this killer has been active. No one can be sure how many victims he has claimed. No one can even be sure if the killings are the work of the same killer or multiple killers. All we can be certain of is that the bodies of 14 people have been discovered. Those that have been identified are believed to have been sex trade workers although one should not assume all of the victims were as not all of the victims have been identified as of yet. One of the victims was a young Asian male while another was a child between 16 and 23 months of age. She has been positively identified as the daughter of another victim of the killer.

07: The Original Night Stalker

Location: California
Active: 1979-1986
Known Victims: 10 (2 more murders believed to be linked to this killer)
Survivors: at least two, maybe more
Suspects: several suspects were investigated but all were cleared
Many of those familiar with true crime stories know the Night Stalker moniker but Richard Ramirez was not the first serial killer to get this tag. The Original Night Stalker was far more prolific than Ramirez, killing at least ten people in under ten years and sexually assaulting at least fifty women in Sacramento between 1976 and 1979. It was originally believed that the murders and the rapes were the work of two separate individuals but all that changed in 2001 when DNA conclusively proved the East Area Rapist and the Original Night Stalker were the same man. Many suspects have been put forth but all have been cleared based on DNA evidence, solid alibis or various other investigative methods. The real perpetrator remains unknown to this day. The crimes did, however, inspire legislation that allows authorities to collect DNA from convicted felons in California so that it may be stored and compared to DNA collected at crime scenes. While this has not helped bring any new suspects in the Original Night Stalker case it has led to new suspects and even convictions in old cold cases many thought would never be solved.

06: The West Mesa Bone Collector

Location: West Mesa, Albuquerque, New Mexico
Active: unknown (bodies discovered on February 2, 2009)
Known Victims: 11
Survivors: unknown
Suspects: no official suspects named
On the surface, the West Mesa murders and the Gilgo Beach murders we talked about a moment ago seem to have a lot in common. In both cases, a number of bodies were uncovered in one area and in both cases, it was clear fairly quickly that those bodies had been dumped by a serial killer. There are other similarities as well but there are also a few key differences. In the Gilgo Beach case, many of the victims remain unidentified while all of the victims of the West Mesa Bone Collector have been positively identified. In addition, authorities have a little more to go on in the way of gathering suspects in the West Mesa case as they believe the murders are connected in some way to the state fair that often attracts a large number of prostitutes. If that is the case, the killer could easily be someone working at the fair or someone who visits the town for the fair every year. Numerous suspects have been investigated, many of them looking like viable possibilities but as of yet, no one has officially been named as a suspect and no one has been arrested.

05: The Boston Strangler

Location: Boston, Massachusetts
Active: 1962-1964
Known Victims: 13
Survivors: no known survivors
Suspects: Albert DeSalvo
My decision to include the Boston Strangler on this list may be a controversial one but I am one of the many people who have read about this case and don’t believe Albert DeSalvo was responsible – at least not on his own. No one is claiming DeSalvo was a completely innocent man but there is a lot of strong evidence that suggests the wrong man may have been convicted of the Stranglers crimes. Why is that a problem? DeSalvo certainly belonged in prison and the streets were a little safer with him in there but the problem lies in the fact that the real Boston Strangler is still out there. Even if he died long ago, he still went to his death bed having never faced justice for the crimes he committed.

04: The Stoneman

Location: Calcutta, India
Active: 1989
Known Victims: 13
Survivors: unknown
Suspects: several arrests of ‘suspicious persons’ were made but no one was convicted
The case of The Stoneman is a difficult one for a few reasons; perhaps the biggest being the idea that the killings attributed him were not the work of a serial killer but were instead a series of unrelated murders. Considering the similar cause of death in each case, the similarities in the choice of victim and the murder weapon used in each case, it’s hard to believe they’re unrelated. The murders in Calcutta also seem to tie in with another string of twelve murders committed in Bombay between 1985 and 1987. In both strings of murders, the killer would approach a homeless person while the person was sleeping and crush their skull with a single blow from a stone. Due to the fact that the victims were only struck once, the stone used is believed to weigh as much as 30 kg. It is worth noting that many believe only twelve of the thirteen murders connected to The Stoneman in Calcutta were actually the work of the same killer as the thirteenth murder did not seem to fit the pattern of the previous murders. Regardless, despite arresting several ‘suspicious persons’ in connection with the murders, no one has ever been convicted and the case remains unsolved.

03: The Cleveland Torso Murderer

Location: Cleveland, Ohio
Active: 1930s for certain but the murders possibly started earlier and concluded later than that.
Known Victims: 12 (authorities believe this number is much higher, possibly as high as 40)
Survivors: unknown
Suspects: several suspects tied to the crimes but never through concrete evidence and therefore no arrests were made.
As the name implies, The Cleveland Torso Murders are a particularly baffling, particularly gruesome series of crimes committed in Ohio in the 1930s, although many believe the Cleveland Torso Murderer may have been active far longer than that. The killer’s total number of victims is also a matter of debate but there are a few things we know for sure. First, many of the victims were never positively identified although it is believed they were mostly drifters or the ‘working poor’ who lived in shanty towns in the Cleveland Flats. We also know the cause of death for most of the Cleveland Torso Murderer’s victims was decapitation. In some cases, the head of the victim was never found. In other cases, only the head was found. The victims were often mutilated with the male victims most often being castrated. These factors not only made the crimes especially shocking and horrific, they also made the crimes very unique; making it easier for authorities to tie multiple killings to the same killer – not that it helped. Although circumstantial evidence as tied many suspects to the crimes, they remain unsolved.

02: The Paraquat Murders

Location: Fukuyama, Hiroshima
Active: 1985
Known Victims: 12
Survivors: no known survivors although it would be difficult to determine due to the nature of the crimes
Suspects: none
So, what we basically have here is a killer that left beverages laced with paraquat, a herbicide, on top of vending machines or around vending machines, prompting vending machine operators to post warnings telling people not to drink any random beverages they found lying around. The person responsible took 12 lives and has never been found. It’s worth noting that after the vending machine operators posted the warnings, the poisonings stopped. I wasn’t able to find out much information about the victims of these crimes but I would imagine they were either homeless people or people of limited means that may have taken the beverages because they didn’t have enough money to buy from the machine. Even if the victims were wealthy people with enough money in their couch cushions to buy the entire vending machine several times over, they didn’t deserve to die for what basically amounted to a lapse in judgement.

01: The Monster of Florence

Location: Florence, Italy
Active: 1968-1985
Known Victims: 16
Survivors: unknown
Suspects: Antonio Vinci, Stefano Mele, Pietro Pacciani, Mario Vanni, Giancarlo Lotti
Sixteen people lost their lives at the hands of the Monster of Florence between 1968 and 1985 but despite several strong suspects and even convictions in the case, many believe none of the men convicted were actually responsible for the crimes and thus, the case remains open and unsolved. The details of the crime and truly horrific and the idea that the person responsible could still be out there is terrifying. Perhaps that has contributed the the false convictions and the continued interest in the case.