The Most Dangerous Active Serial Killers In 2020

In a world that tends to frown on murdering your fellow man, serial killers are often considered the worst of the worst. Yet, they're very, very real. It's borderline unbelievable that anyone would choose to kill people over and over again. It's even harder to believe that there are actually plenty of people like that out there: According to the Atlantic, the FBI believes that under one percent of all unsolved murders are the work of serial killers. Meanwhile, Thomas Hargrove of the Murder Accountability Project thinks that as of 2019, the U.S. alone had something like 2,100 unidentified serial killers running around. Author and former police detective Michael Arntfield thinks that the number could be as high as 4,000.   

Obviously, we have no way to know for sure which of these undiscovered serial killers are most terrifying, because, well, they haven't been caught yet. Still, we definitely do know about some of them ... and what we know is pretty scary. Let's take a look at some of the most dangerous serial killers who are still out and about in 2020.

Pedro Alonzo Lopez may have killed over 300 people

When you're known as "The Monster of the Andes," you have a lot of monstrosity to live up to, and according to Biography, Pedro Alonzo Lopez is as terrifying as they come. The Colombian serial killer and diagnosed sociopath wandered around Peru and Ecuador, targeting young girls. While it's estimated that he may have killed over 300 people, he was ultimately convicted for "just" 110 murders. 

What is Lopez doing on this list if we already know who he was and he's already been caught? Well, they did indeed catch him in 1980, but seeing as this was in Ecuador, the country's laws only allowed a maximum prison sentence of 16 years. Out of these, he spent 14 years in a prison. In 1995, he was released for good behavior, and deported to his native Colombia, where he was declared insane and put in a psychiatric hospital. In early 1998, he was declared sane, which proved to be a bad move. Lopez promptly visited his elderly mother to demand his inheritance, and upon learning that she was poor, he sold her possessions (a chair and a bed) on the street. After that, he disappeared without a trace. No one knows where this terrifying man is today, though there is some concern that he may have had a hand in at least one murder since his vanishing act.   

The mysterious smiley face drownings

Imagine a group that ruthlessly stalks young, inebriated victims, and kills them in a way that makes it very difficult to tell whether the death was accidental or not. As Rolling Stone reported in 2019, professor of criminal justice Lee Gilbertson and former NYPD detectives Kevin Gannon and Anthony Duarte think this terrifying scenario is a very real thing. Since 2008, they have posited a theory that some sort of gang or a group of "domestic terrorists" is targeting young, white men with a college education, often after a night of drinking. They abduct them, murder them, and make the deaths look like accidental drownings. The only sign of their involvement is an ominous smiley face graffiti near the alleged crime scenes. 

If you think it's more than possible a young guy with some alcohol in his blood stream might indeed drown accidentally, well, the FBI agrees with you. Then again, Gilbertson, Gannon, and Duarte say they've discovered that some of the over 40 victims they believe to have identified have been missing for weeks, yet their bodies only showed signs of having only been dead for days upon discovery. The bodies also have traces of the infamous date drug GHB, which could have been used to incapacitate the victims before kidnapping them. Even more chillingly, the trio think that the "Smiley Face Killers" might be involved in as many as 335 deaths. Accidental drownings or serial killers, that's a lot of senseless death.

The Freeway Phantom serial killer terrorized Washington D.C.

You'd be forgiven for not being familiar with the Freeway Phantom. According to Cheryl W. Thompson of the Washington Post, this brutal serial killer operated around Washington D.C. during the ruthless early 1970s, when the homicide investigators in the area were up to their eyebrows in murder cases. Nevertheless, this particular serial killer stood out. The murderer's reign of terror started in April 1971, and over the next 17 months, he abducted and killed six young African-American girls and left their bodies near large roads with plenty of traffic. The case became known as the "Freeway Phantom Murders," and frighteningly, the killer was never caught. If he's alive, he may well still be out there somewhere. 

A large part of why the Freeway Phantom was never caught was the unfortunate fact that he's thought to have been the first serial killer in the area, so apart from the victims' families and a sympathetic detective called Romaine Jenkins, no one really knew (or cared) how to proceed with the investigation, at least until the FBI stepped in ... in 1974. Unfortunately, while their sizable task force was able to comb through every existing lead and go through hundreds of suspects, and despite some lines of investigation with lots of potential, the killer was never found.

The Highway of Tears may be the hunting ground of serial killers

Highway of Tears, as the New York Times reports, is the less than flattering nickname for Highway 16, an isolated, 450-mile stretch of road in Canada's British Columbia. The road has a dark reputation, and for a good reason. Along it and two others roads connecting to it, dozens of girls and women have been murdered ... or they've simply disappeared. Almost all of the victims have been indigenous, and almost all the cases are unsolved.

It's pretty clear that there is a killer about — or rather, several killers, seeing as the Royal Canadian Mounties have connected cases going back to at least 1969. The official number of dead or missing women on the Highway of Tears between the years 1969 and 2006 was 18, but many believe that the number could be as high as 50. 

To be fair, it's unlikely that all of these deaths are the work of a single killer. We know this because one serial killer has already been caught: In 2014, Cody Legebokoff was convicted for killing four women near the infamous road. Unfortunately, British Columbia has a reputation for serial killers who target indigenous women, and seeing as Legebokoff was only 24 when he was convicted and his crimes were only a small fraction of all the unsolved cases, the Highway of Tears' fearsome reputation lives on.

The Zodiac killer was never caught

Apart from Jack the Ripper, the Zodiac Killer is arguably the most famous unsolved serial killer case out there. Unlike the Ripper, however, there's a chance that the Zodiac might still be walking among the living, looking to make them dead. As Biography tells us, the Zodiac Killer murdered at least five people in the San Francisco Bay Area in 1968 and 1969, taunting the press and the police with boastful letters, phone calls, and strange codes. There's a possibility that he also committed other murders before these famous ones. 

Despite a robust amount of leads — from fingerprint evidence to eyewitness accounts and a police sketch — and the killer's own, constant messages, no suspect was ever arrested and the killings eventually stopped. While some of the potential candidates to don the Zodiac Killer's hood have already died, the fact that we still have no idea about his identity means that he could very well still be out there ... though he'd probably be at least in his late seventies. 

The Monster of Florence is an Italian mystery killer

What's worse than one serial killer? The possibility that there might be more than one. Such is the case with the Monster of Florence, who Encyclopedia Britannica tells us started his reign of terror in 1968 and continued until 1985. The exceptionally brutal murderer targeted couples in the hills near the city, and killed at least 16 people over the years. 

As the Atlantic tells us, the hunt for the Monster was a long one, and tens of thousands of men were viewed as potential suspects. The husband of the first victim was actually convicted for the murder and received a 14-year prison sentence, though the killings soon resumed. In 1994, the investigators finally believed they had their man, in the form of a drunken, violent farm worker called Pietro Pacciani. His conviction was promptly overturned, but soon afterward, the police discovered a witness who claimed that Pacciani and a number of accomplices had in fact been killing people at the behest of a devil-worshiping doctor and other "masterminds." Pacciani died before his second trial, and though two of his apparent accomplices were eventually convicted, the evidence against them was shoddy at best. As such, some people who are extremely familiar with the case, such as crime journalist Mario Spezi, believed in 2006 that the true Monster of Florence (or perhaps monsters) was still out there ... and, seeing as he still hasn't been caught, might still be. 

A serial killer may be at work on Long Island's Gilgo Beach

Gilgo Beach on Long Island, New York, might not seem like the most terrifying place on Earth. However, it just might be the stalking ground of one of the most infamous undiscovered serial killers out there. Ella Torres of ABC News took a look at the information available about the suspected Long Island Serial Killer case in early 2020, and what we have is as creepy as it is shrouded in mystery. 

It all started in late 2010, when bodies of missing sex workers and unidentified people started turning up on the remote beach. Over the course of a few months, the remains of no less than 10 victims were discovered scattered around the area. And ... that's all we have, really. The police have not revealed the exact causes of death or the surrounding circumstances, though they have revealed that one of the victims made a frenzied 911 call about a client who was trying to kill her. Then, she disappeared. We also don't know whether this is the work of one serial killer or multiple individuals, though several investigators and experts tend to refer to the culprit as a single "he," based on a mocking phone call the killer reportedly made to one victim's sister. Still, there's obviously something very, very strange afoot on Gilgo Beach.  

The complex case of the Frankford Slasher

As NBC Philadelphia tells us, the Frankford Slasher terrorized the northern parts of the city of Philadelphia from 1985 to 1990. The serial killer seems to have exclusively assaulted and killed Caucasian women who visited the bars of a specific area on Frankford Avenue, claiming eight or nine victims before the killings stopped. That approximate "eight or nine" figure, incidentally, is due to the fact that a man called Leonard Christopher was convicted of one of the first eight murders and given a life sentence. Though one more murder happened while he was already incarcerated, he still became the public face of the Slasher at the time, and spent the rest of his days in prison for a crime experts believe he did not commit. The other eight murders remain unsolved.   

Though this means that an unknown serial killer might still be on the loose somewhere out there, there might be some light at the end of the tunnel. During the investigation, the Philadelphia police did actually find a potential suspect: A middle-aged man claiming to be a minister. Though this person disappeared after initial questioning, the police did secure a DNA sample, which was being investigated with new techniques as of 2019. 

The Chillicothe case might be the work of a serial killer

Someone in the small city of Chillicothe in Southern Ohio has a dark secret. As David Lohr of Huffington Post and Jona Ison of the area's own Chillicothe Gazette tell us, over the course of 2014 and 2015, no less than six women disappeared around there. Some of them haven't been seen since, while others have turned up dead at various spots. To be fair, the authorities haven't used the term "serial killer" quite yet, except in carefully structured sentences that begin with something like, "No one has said there's a ..." However, the media has been happy to drum up the serial killer angle, and as Michael E. Miller of the Washington Post reported in 2015, the locals certainly seem to think that's what they're dealing with. 

While the Chillicothe case remains unsolved at the time of writing, and therefore it's possible that the perpetrator remains on the loose, it's worth noting that a news story from a couple of hours' drive away may or may not shed some light to the situation. As CBS News reports, in 2015, a West Virginia woman fought off an attacker and ended up shooting him with his own gun. The man turned out to be Neal Falls, a suspected serial killer with possible connections to up to 10 deaths. 

Colonial Parkway serial killer may have been a cop

The Colonial Parkway is 23 miles of beautiful Virginia road running between Yorktown and Jamestown, and as such, far from a terrifying, serial killer-y location. Still, as crime writer David Lohr of the Huffington Post tells us, the stretch has seen its share of bloodshed in the shape of a suspected serial killer. The Colonial Parkway murders consisted of eight killings between 1986 and 1989, and the similarities between the murders have led some to believe that they might be the work of the same person. Some theories have suggested that the killer might either be a law enforcement officer or impersonating one, because the cars of some of the victims were discovered with the driver's window rolled down. 

Incidentally, the case might have faded into obscurity over time, if it wasn't for a former deputy called Fred Atwell, who emerged with a stack of 84 undiscovered crime scene photographs in 2009, and started butting into the revitalized investigation at every opportunity. Despite the red flags Atwell's increasingly odd behavior raised, the case remains unsolved, and the Colonial Parkway Murders Facebook page reported his death on December 2018. However, as Alexa Doiron of Williamsburg Yorktown Daily reported on October 2019, the situation might be about to change. There's a TV show about the crimes in the works, and it centers around an ace team of former FBI special agents who feel that they may be able to crack the case. 

The I-70 killer disappeared without a trace

In 1992, Interstate 70 was a dangerous place, and it wasn't because of the traffic. As Vox tells us, that year's spring was marked by the bloody trail of a serial killer who murderer six clerks in stores near the I-70 in an identical fashion, starting in Terre Haute, Indiana and ending in Wichita, Kansas. There's little question that it was the same killer every time, seeing as he used the same rifle in all cases, and seemed to exclusively target brunette women — though one of the victims actually turned out to be a guy with a long hair. He didn't just randomly enter gas stations and attack people, either — some of the victims worked in shoe stores, others sold herbs and health products.

There were several eyewitnesses who described the man as 5'7 with "light brown or red hair," who wore a gray sports coat and slacks. Despite this, the investigators have found the case impossible to crack. There have been no known murders by the same perpetrator since the events of 1992. No one's even been able to establish a motive, and the killer only took a small amount of money from the stores' cash registers. According to Jon Webb of the Courier & Press, the case was still unsolved as of December 2019, and some of the victims' families have essentially given up on ever finding out the truth behind the deaths.

We've only started to learn about the Chicago Strangler

"Chicago Strangler" may sound like a historical villain who stalked the Windy City sometime during the Great Depression, but as Pam Zekman of CBS Chicago and Daniel Tucker of WBEZ Chicago both told us in 2019, this is one serial killer whose terrifying tale might only be beginning to unfold. For around two decades, Chicago has seen a series of eerily similar strangulation murders. The first victim was found in 2001, and bodies have turned up in empty lots, vacant buildings, dark alleys and even garbage containers ever since then, with only a short period of peace between 2014 and early 2017. The victims have largely been women with a history of sex work or addiction, and there have been a lot of them — in fact, the Chicago Police Department and the FBI are investigating no less than 51 unsolved murders, in an attempt to find out whether they might be the work of at least one serial killer.

If you ask Thomas Hargrove, the chairman of the Murder Accountability Project nonprofit, at least some of them most likely are. Hargrove says that his group has a "serial killer detector" algorithm, which has been pointing at a serial killer situation in Chicago for years.

The Rainbow Maniac of Brazil

"Rainbow Maniac" might seem like a suspiciously colorful moniker for a serial killer, until you realize it refers to a murderer who targeted gay men. As the Guardian and the Sydney Morning Herald tell us, this ruthless villain started their reign of terror over the Carapicuiba area of São Paulo, Brazil in July 2007. By August 2008, the killer was suspected of murdering at least 13 and possibly as many as 16 people.  

The murders were pretty much the definition of hate crime. The killer scoured for victims in a popular hangout location known as Paturis Park, and shot all but one to death, often with their pants quite literally down to their knees. Though the killings were originally investigated as individual homicides, their ruthlessness and the great number was enough to stand out from the usual violence in the city. The police soon figured out that they were dealing with a homophobe serial killer. "In his head, he thinks he is doing a clean-up job," police chief Paulo Fernando Fortunato said. "He doesn't like homosexuals, he hates them."

Unfortunately, the Rainbow Maniac may very well still be out there. The police did arrest a retired police officer for the crimes in 2009, but local outlet Agora São Paulo reports that the man was found innocent and acquitted in 2011 ... and it looks like the case hasn't proceeded since.  

The vending machine killer may have copycats

In 1985, people in Japan started dying after drinking a popular beverage called Oronamin C, which someone had laced with a herbicide called paraquat, per CBC. The police soon started suspecting that the killer was leaving the tampered drinks in the slots of the country's omnipresent vending machines. There, they were found and eventually consumed by the unwary victims who, according to the New York Times, may simply have assumed that the extra drink was a part of a promotional campaign. 

It's estimated that as many as 12 people died because of the poison drinks, and many others became ill. It's hard to say whether all of these deaths were the product of one deranged mind, due to the fact that the high-profile case attracted several copycat poisoners. Regardless of the killer's true body count, they walked free — in fact, the case remains so unsolved that it appears no suspects have ever even been arrested.

The West Mesa murders remain unsolved

It's rare to hear officials throw the term "serial killer" around before they're fairly certain that their homicide cases involve one. As such, the fact that the City of Albuquerque straight up uses the name "West Mesa Serial Killer" is a pretty good sign that one is involved. 

The West Mesa Serial Killer is an unapprehended and unknown individual who murdered 11 young women, one of whom was pregnant, and buried them in clumsy graves in West Mesa, Albuquerque. The skeletal remains were discovered in 2009, and as the Albuquerque Journal tells us, the police swiftly put together a 40-strong task force to investigate the case. Unfortunately, it turned out that the women had been murdered — strangled, possibly — sometime between 2003 and 2005, so the trail was colder than anyone would have wanted.

While there have been at least two potential suspects, as of 2016 there had been zero arrests. At that point, only a single detective was investigating the case full-time. As such, families of the victims aren't exactly hopeful that they will get answers in the immediate future. What's more, it's possible that the killer may have had even more victims than anyone realizes. In fact, apart from the 11 known victims, at least six other women from similar backgrounds went missing in the area between 2001 and 2006. 

Two Cheshire double murders are far too similar

In August 2020, the Sunday Times (via the Telegraph) reported that the otherwise unassuming Cheshire, UK might be the secret hunting ground of a serial killer. According to a 179-page confidential report by a local senior coroner's officer, modern research techniques suggest that two supposedly unconnected murder-suicide cases might be considerably more terrifying than such cases already are, due to the possibility that they might not be quite that unconnected after all. 

The two suspected double homicides of elderly couples were particularly bloody, with both sharp and blunt instruments involved. Both happened in the Wilmslow area of Cheshire, in 1996 and 1999 — a mere three years and two miles apart. Reportedly, the text also suggests that further cases should be looked into, and alerts Interpol and the National Crime Agency to look into similar cases in both the UK and other European countries. "This individual will not stop killing until someone or something stops him," the report allegedly says.

According to the Guardian, as of August 2020, authorities were looking into no less than five different murder-suicide cases that might be the work of the same person. What's more, the story states that between 2000 and 2019, there have been no less than 39 similar cases in the UK alone. It remains to be seen how this chilling case develops, and how many — if any — of these cases turn out to be the work of the same person.