25 Most Evil Serial Killers Of The 20th Century
Few subjects grip the human imagination quite like the psychology of serial killers. These individuals represent the darkest extremes of human behavior — methodical, calculating, and utterly devoid of empathy for their victims. The 20th century, in particular, produced an alarming number of killers whose crimes shocked entire nations and permanently changed how law enforcement investigates violent crime.
Understanding the 25 most evil serial killers of the 20th century isn’t about glorifying monsters. It’s about examining what drove them, how they evaded capture, and what their stories reveal about the vulnerabilities in our social fabric. The cases profiled here span six decades, multiple continents, and a chilling variety of methods — from a trusted family doctor in England to a charming law student in America.
Whether you’re a true crime enthusiast or simply trying to understand one of history’s darkest chapters, this list pulls no punches. These are the men and women whose names became synonymous with evil — and whose crimes forced society to confront uncomfortable truths about predators hiding in plain sight.
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What Defines a Serial Killer?
Before diving into the list, it’s worth establishing what separates a serial killer from other types of violent offenders. The FBI defines a serial killer as someone who commits two or more murders in separate events, with a “cooling-off” period between each crime. This distinguishes them from mass murderers (who kill multiple people in a single event) and spree killers (who commit murders in rapid succession without pausing).
Serial killers typically exhibit a distinct modus operandi (MO) — a preferred method, victim type, or location. Many also leave a “signature,” an emotionally significant element tied to their personal psychology. Their motivations range from sexual gratification and a lust for power to financial gain and deeply warped psychological compulsions.
With that context in mind, here are the 25 most evil serial killers of the 20th century.
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The 25 Most Evil Serial Killers of the 20th Century
1. Ted Bundy — The Charming Predator
Ted Bundy is perhaps the most well-known serial killer in American history, and for good reason. Handsome, articulate, and deceptively charming, he used his looks and social intelligence to lure young women and girls to their deaths throughout the 1970s.
Bundy confessed to 30 homicides committed across seven states between 1974 and 1978, though investigators believe his true victim count could be significantly higher. He was a necrophile who often returned to his victims’ bodies, and he evaded capture for years despite multiple opportunities for law enforcement to catch him.
He was executed in Florida’s electric chair on January 24, 1989 — reportedly watched by a crowd of spectators gathered outside the prison. His case directly contributed to the FBI developing its modern criminal profiling techniques.
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2. Jeffrey Dahmer — The Milwaukee Cannibal
Jeffrey Dahmer committed some of the most disturbing crimes in recorded American history. Between 1978 and 1991, he murdered and dismembered 17 men and boys, with later crimes involving necrophilia, cannibalism, and attempts to create “zombies” by drilling into his living victims’ skulls.
Dahmer’s case exposed catastrophic failures in the Milwaukee police department. In one notorious incident, officers returned a young victim — who had escaped — directly to Dahmer’s apartment after he convinced them the boy was his adult partner. That victim, Konerak Sinthasomphone, was 14 years old.
Dahmer was bludgeoned to death by a fellow inmate at the Columbia Correctional Institution in November 1994, just three years into his multiple life sentences.
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3. John Wayne Gacy — The Killer Clown
John Wayne Gacy built a life that appeared respectable from the outside — a contractor, a Democratic Party volunteer, and a man who performed as “Pogo the Clown” at charity events. Underneath that mask was a predator who sexually assaulted and murdered at least 33 teenage boys and young men between 1972 and 1978 in Cook County, Illinois.
Gacy buried 26 of his victims in the crawl space beneath his home. Neighbors had complained about a foul smell for years before police finally investigated in December 1978.
He was executed by lethal injection on May 10, 1994, spending his final years on death row painting self-portraits — many of which fetched thousands of dollars at auction.
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4. Harold Shipman — Dr. Death
Harold Shipman holds the grim distinction of being the most prolific serial killer in modern recorded history. A trusted British general practitioner in Hyde, Greater Manchester, he murdered an estimated 250 patients — mostly elderly women — by administering lethal doses of diamorphine (medical-grade heroin).
The sheer audacity of his crimes is staggering. Shipman killed his victims during routine house calls and surgery visits, then falsified death certificates to cover his tracks. He was only caught in 1998 when a fellow GP noticed an unusually high death rate among his patients and the suspicious language in the death certificates he’d signed.
Convicted of 15 murders in January 2000, Shipman hanged himself in his prison cell on January 13, 2004 — the day before his 58th birthday, denying his victims’ families the chance to ever hear a confession or explanation.
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5. Andrei Chikatilo — The Butcher of Rostov
Andrei Chikatilo was a Soviet school teacher and Communist Party member who led a double life as one of history’s most savage killers. Between 1978 and 1990, he sexually assaulted, murdered, and mutilated at least 52 women and children across Russia and Ukraine.
Chikatilo’s crimes were particularly brutal — he mutilated his victims’ eyes, believing they could photograph his face. Soviet authorities initially refused to acknowledge the murders, even executing an innocent man for crimes Chikatilo had committed.
He was finally arrested in 1990 and confessed to all 52 killings. Executed by a single gunshot to the back of the head on February 14, 1994, his case exposed the deep failures of the Soviet criminal justice system.
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6. Gary Ridgway — The Green River Killer
Gary Ridgway was convicted of 49 murders, making him one of the most prolific convicted serial killers in U.S. history. He targeted sex workers and runaway girls in Washington state throughout the 1980s and 1990s, strangling his victims and dumping their bodies — often in clusters — near the Green River south of Seattle.
Ridgway evaded capture for nearly two decades, even passing a polygraph test in 1984. He was finally caught in 2001 through DNA evidence that linked him to his victims’ remains. In exchange for helping investigators find the remains of victims still missing, he avoided the death penalty.
He is currently serving 48 consecutive life sentences without the possibility of parole in the Washington State Penitentiary.
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7. Richard Ramirez — The Night Stalker
Richard Ramirez terrorized the residents of Los Angeles and San Francisco between 1984 and 1985 in a crime spree that paralyzed two of California’s largest cities. He committed at least 13 murders, 11 sexual assaults, 5 attempted murders, and dozens of burglaries — attacking victims at random in their own homes in the middle of the night.
Ramirez was a Satanist who left occult symbols at crime scenes and shouted “Hail Satan!” in court when his death sentence was announced. He was finally identified through a fingerprint on a stolen car in August 1985, and was beaten by a group of East Los Angeles residents before police could arrest him.
He died in prison on June 7, 2013, from complications of B-cell lymphoma while awaiting execution.
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8. Aileen Wuornos — A Case of Disputed Motives
Aileen Wuornos became one of America’s most notorious female serial killers after murdering seven men in Florida between 1989 and 1990. A sex worker, she consistently claimed that all of her victims had raped or attempted to rape her, framing her actions as self-defense.
Forensic evidence and court proceedings contradicted at least several of those claims. Her story drew worldwide attention and inspired the 2003 film Monster, for which Charlize Theron won an Academy Award.
Wuornos was executed by lethal injection on October 9, 2002, making her one of the few women executed in the United States in the modern era.
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9. Dennis Rader — The BTK Killer
Dennis Rader murdered ten people in Wichita and Park City, Kansas, between 1974 and 1991, giving himself the acronym “BTK” — Bind, Torture, Kill — in taunting letters he sent to police and local media. Then, bafflingly, he stopped for over a decade.
Rader was a church president, a compliance officer, and a family man — the ultimate wolf in sheep’s clothing. He resumed contact with authorities in 2004 after a newspaper article questioned whether his old letters were authentic. In a moment of stunning arrogance, he sent investigators a floppy disk that contained metadata linking it to his church’s computer.
Arrested in February 2005, Rader was sentenced to ten consecutive life sentences. His victims have never received a satisfying explanation for why he stopped killing for 14 years.
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10. Samuel Little — America’s Most Prolific Killer
Samuel Little is the most prolific serial killer in U.S. history, confessing to the murders of 93 women across 19 states between 1970 and 2005. The FBI has verified 60 of those confessions, with investigations into the remaining claims still ongoing at the time of his death.
Little targeted vulnerable women — often sex workers and drug addicts — whose disappearances were less likely to trigger immediate police investigations. He would strangle them with his bare hands during or after sexual encounters, leaving few forensic traces.
He was convicted of eight murders and died in prison on December 30, 2020, at age 80. His case highlighted a systemic failure to investigate missing persons from marginalized communities.
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11. Charles Manson — The Cult Leader Who Didn’t Pull the Trigger
Charles Manson never personally committed the murders that made him infamous — but he orchestrated them with chilling precision. In August 1969, members of his “Manson Family” cult murdered nine people in two nights, including actress Sharon Tate, who was eight months pregnant.
Manson’s genius lay in his ability to psychologically dominate followers, convincing them to kill on command. He believed the murders would ignite a race war he called “Helter Skelter,” referencing the Beatles song.
Manson died in prison on November 19, 2017, at age 83, having never been released despite multiple parole hearings. The Manson Family murders remain one of the most psychologically complex cases in American criminal history.
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12. David Berkowitz — Son of Sam
For 13 months between 1976 and 1977, David Berkowitz held New York City in a grip of terror. Armed with a .44 caliber revolver, he murdered six people and wounded seven others in a series of apparently random attacks, targeting young women and couples parked in cars.
Berkowitz claimed he was commanded to kill by a demon that possessed his neighbor’s dog — a story that earned him the enduring nickname “Son of Sam.” He left mocking letters at crime scenes addressed to police detective Joseph Borelli.
Caught in August 1977, he is serving 365 years in Shawangunk Correctional Facility in New York, where he has reportedly become a born-again Christian.
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13. Pedro Lopez — The Monster of the Andes
Pedro Lopez is one of the most disturbing names on this list — not just for his crimes, but for what happened after his capture. The Colombian serial killer and rapist claimed to have murdered over 300 young girls across Colombia, Ecuador, and Peru, with at least 110 confirmed victims discovered after he led police to their burial sites in 1980.
After serving just 18 years in a Ecuadorian psychiatric facility, Lopez was released in 1998 on good behavior. He was briefly re-arrested in Colombia in 2002 but released again. His current whereabouts remain unknown.
The Monster of the Andes may still be alive and free — a fact that has horrified victims’ families and law enforcement officials for decades.
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14. Edmund Kemper — The Co-ed Killer
Edmund Kemper is a paradox that criminologists still study today. Highly intelligent, standing 6 feet 9 inches tall, and with an IQ of 145, he is one of the most articulate and self-aware killers ever interviewed — and one of the most disturbing.
Kemper began by murdering his paternal grandparents at age 15. Released at 21 after being declared sane, he went on to murder six female college students in California between 1972 and 1973, committing necrophilia and cannibalism. His final victims were his own mother and her friend.
He voluntarily called police to confess and is currently serving eight concurrent life sentences. His lengthy FBI interviews helped shape modern criminal profiling and inspired aspects of the TV series Mindhunter.
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15. Albert DeSalvo — The Boston Strangler
Between 1962 and 1964, a killer terrorized Boston, strangling 11 women in their apartments and leaving their bodies in signature poses. Albert DeSalvo confessed to all 11 murders, earning the nickname “The Boston Strangler.”
However, his case remains controversial. DeSalvo was never tried for the murders — only for unrelated sex crimes — and serious doubts about whether he was the sole perpetrator have persisted for decades. In 2013, DNA evidence confirmed DeSalvo’s presence at the scene of one victim, Mary Sullivan, but questions about the other ten cases remain unresolved.
DeSalvo was stabbed to death by an unknown assailant at Walpole State Prison on November 25, 1973, taking many of his secrets to the grave.
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16. Dennis Nilsen — Britain’s Domestic Monster
Dennis Nilsen was a British civil servant and former soldier who murdered at least 12 young men and boys in London between 1978 and 1983. Nilsen would invite lonely, often homeless young men to his home, kill them, and then keep their bodies for companionship — sometimes for months — before dismembering and disposing of them.
He was only discovered in 1983 when a plumber called to unblock a drain outside his flat found human flesh and bones. Nilsen reportedly said, “I think it’s your drains,” when the plumber raised the alarm.
Sentenced to life imprisonment, he died in prison on May 12, 2018. His case inspired the Netflix drama Des, starring David Tennant.
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17. Peter Sutcliffe — The Yorkshire Ripper
Peter Sutcliffe murdered 13 women and attempted to kill seven more across Yorkshire and Greater Manchester between 1975 and 1980 in one of Britain’s most exhaustive manhunts. He attacked his victims with a hammer and screwdriver, and the investigation — hampered by a hoax tape claiming to be from the killer — lasted five years and involved over 250 detectives.
Sutcliffe was finally caught in January 1981 during a routine police stop. He was found with a woman he had picked up and was carrying a hammer and knife.
Sentenced to 20 concurrent life sentences, he contracted COVID-19 in prison and died on November 13, 2020.
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18. The Zodiac Killer — The Case That Was Never Solved
The Zodiac Killer operated in Northern California between 1968 and 1969, killing at least five confirmed victims and claiming responsibility for 37 total murders in cryptic letters sent to newspapers. The letters included ciphers, some of which remained unsolved for over 50 years — a 340-character cipher wasn’t cracked until December 2020.
What makes the Zodiac case so enduring is its absolute lack of resolution. Despite one of the most intensive investigations in California history, no one was ever charged. Theories have pointed to dozens of suspects over the decades, most recently a man named Gary Francis Poste in 2021, but no definitive identification has been made.
The case remains officially open.
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19. John George Haigh — The Acid Bath Murderer
John George Haigh operated in Britain during the 1940s, murdering at least six people — though he claimed nine — and dissolving their bodies in 40-gallon drums of sulfuric acid. He believed that without a body, there could be no murder conviction. He was wrong.
Haigh was a meticulous con man who targeted wealthy acquaintances, forging their signatures to steal their assets after their deaths. His downfall came when investigators discovered human bone fragments, a gall stone, and a set of dentures that survived the acid baths.
Executed at Wandsworth Prison on August 10, 1949, Haigh bequeathed his clothing to Madame Tussauds wax museum, requesting that his effigy always be impeccably dressed.
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20. Angelo Buono Jr. & Kenneth Bianchi — The Hillside Stranglers
Between 1977 and 1979, cousins Angelo Buono Jr. and Kenneth Bianchi murdered 10 young women and girls in Los Angeles, posing as police officers to lure their victims into their car before subjecting them to prolonged rape and torture.
Their victims ranged in age from 12 to 28. The cousins were meticulous about leaving no forensic evidence, cleaning the bodies before dumping them on hillsides — earning them their infamous nickname.
Bianchi was caught after committing two additional murders in Washington state in 1979. Buono was convicted in 1983 and died in prison in September 2002. Bianchi is still serving multiple life sentences.
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21. Robert Pickton — The Pig Farm Killer
Robert Pickton ran a pig farm in Port Coquitlam, British Columbia, where he lured vulnerable women from Vancouver’s Downtown Eastside and murdered them. The remains of 33 women were found on his property, though Pickton claimed to have killed 49 victims total — bragging to an undercover officer that he wanted to make it an even 50.
His case exposed serious failures in how police handled missing persons reports from Indigenous and marginalized women in Vancouver, leading to a national inquiry into missing and murdered Indigenous women in Canada.
Convicted of six second-degree murder counts in 2007, Pickton died following a workplace accident in prison on February 3, 2024.
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22. Dean Corll — The Candy Man
Dean Corll was a Houston electrician who worked part-time at his family’s candy factory, which is how he earned his chilling nickname. Between 1970 and 1973, Corll — with the help of two teenage accomplices, David Brooks and Elmer Wayne Henley — abducted, tortured, raped, and murdered at least 28 young boys in Houston, Texas, making it the deadliest known serial killing case in American history at the time of its discovery.
Corll’s killing spree ended on August 8, 1973, when 17-year-old accomplice Elmer Wayne Henley shot him during an argument. It was Henley who then led police to the bodies.
The Houston Mass Murders, as they became known, shocked a nation that had assumed serial killers didn’t target young boys.
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23. Juan Corona — The Machete Killer
Juan Corona was a Mexican-American labor contractor who in 1971 murdered 25 migrant farmworkers in Sutter County, California, burying their bodies in shallow graves in peach orchards near the Feather River. All of the victims were men he had hired for farm work.
The discovery of the graves — found when a farmer noticed a freshly dug hole on his land — led to one of the largest excavations of murder victims in U.S. history at the time.
Corona was convicted in 1973, but a retrial was ordered in 1978 after his original attorney was found to have provided inadequate counsel. He was convicted again in 1982 and died in the California Medical Facility in Vacaville on March 4, 2019.
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24. Jerry Brudos — The Shoe Fetish Slayer
Jerry Brudos murdered four young women in Oregon between 1968 and 1969, driven by a deeply entrenched fetish for women’s shoes that had dominated his psychology since childhood. He would abduct, kill, and mutilate his victims, keeping feet and other body parts as trophies.
What makes Brudos particularly chilling is how ordinary he appeared. He was a married father of two, living in a quiet neighborhood in Salem, Oregon. His wife reportedly accepted the locked garage workshop where Brudos committed his crimes as simply a private hobby space.
He was convicted in 1969 and died at the Oregon State Penitentiary on March 28, 2006, having served 37 years.
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25. Ted Kaczynski — The Unabomber
Ted Kaczynski occupies a unique place in this list because his crimes were ideological rather than predatory. A former mathematics professor at UC Berkeley with a Harvard degree, Kaczynski conducted a nationwide bombing campaign from 1978 to 1995, mailing and hand-delivering bombs that killed 3 people and injured 23 others.
His targets were universities and airlines — hence the FBI code name “UNABOM.” He sent a 35,000-word manifesto to newspapers demanding it be published, threatening further attacks if they refused. The Washington Post published it in 1995 — a decision that led directly to his capture, as his brother David recognized the writing style and contacted the FBI.
Kaczynski was serving eight life sentences when he died at the Federal Medical Center in Butner, North Carolina, on June 10, 2023.
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The Psychology Behind These Killers
What do these 25 individuals have in common? Criminologists have identified several recurring factors across the most evil serial killers of the 20th century:
– Childhood trauma: Abuse, neglect, and unstable home environments appear in a disproportionate number of their backgrounds
– Psychopathic traits: A lack of empathy, manipulative behavior, and an absence of remorse are hallmarks of most profiled cases
– Power and control: Many killers describe a need for absolute dominance over their victims as a primary motivator
– Fantasy escalation: Most developed violent fantasies years before acting on them, with the fantasies gradually becoming more detailed and urgent
It’s important to note that trauma and psychological disorders are extremely common — the vast majority of people who experience them never harm anyone. Serial killing requires a specific and rare convergence of factors that researchers are still working to fully understand.
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How These Cases Changed Law Enforcement
The crimes of the 20th century’s most notorious serial killers didn’t just devastate communities — they transformed how law enforcement operates:
– Criminal profiling emerged directly from FBI interviews with killers like Ted Bundy and Edmund Kemper in the 1970s and 1980s
– VICAP (Violent Criminal Apprehension Program) was established in 1985 specifically to track and connect serial crimes across jurisdictions
– DNA forensics became a crucial investigative tool, eventually catching killers like Gary Ridgway decades after their crimes
– Missing persons investigations were overhauled following cases like Pickton’s, where systemic failures allowed killers to operate undetected for years
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Frequently Asked Questions
Who is the most prolific serial killer of the 20th century?
Samuel Little holds the record for most confessed killings by an American serial killer, with 93 confirmed victims across 19 states between 1970 and 2005. Globally, Harold Shipman — with an estimated 250 victims — is often cited as the most prolific in terms of confirmed murders.
Were any of the 25 most evil serial killers ever released from prison?
Pedro Lopez is the most disturbing case — convicted of over 110 murders, he was released from a psychiatric facility in Ecuador in 1998. His current whereabouts remain unknown. The vast majority of killers on this list either died in prison, were executed, or are still serving life sentences.
What is the difference between a serial killer and a mass murderer?
A serial killer commits murders in separate events with a “cooling-off” period between them. A mass murderer kills multiple people in a single event or location. The motivations and psychological profiles are generally very different.
Why do serial killers often target specific types of victims?
Most serial killers have a “victim typology” shaped by their psychological profile and fantasies. Targeting a consistent type of person makes their crimes feel more controlled and predictable to them. It also sometimes means victims from marginalized communities — whose disappearances go less investigated — are disproportionately targeted.
How were most 20th century serial killers eventually caught?
Methods varied widely: forensic evidence (especially DNA), tips from the public, killers contacting police themselves (Kemper, BTK), accomplices turning on them (Corll), or simple police stops (Sutcliffe). Many were caught by a combination of old-fashioned detective work and critical forensic breakthroughs.
Is it true that most serial killers appear completely normal to those around them?
Many do. Bundy, Gacy, Rader, and Shipman all maintained convincingly normal social lives. This is precisely what makes their cases so disturbing — and why the “monster hiding in plain sight” narrative remains so persistently compelling.
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Final Thoughts
The 25 most evil serial killers of the 20th century represent something that continues to disturb us precisely because it resists easy explanation. These weren’t creatures from horror films — they were neighbors, doctors, tradesmen, and teachers. Their crimes forced law enforcement to evolve, prompted society to examine how marginalized communities are protected, and revealed just how effectively a predator can hide behind a mask of normalcy.
Their stories serve as a permanent reminder of vigilance, and of the importance of taking threats seriously — especially when victims come from communities that history has too often overlooked. The legacy of their victims deserves to be remembered not as footnotes to a killer’s story, but as the central reason these cases demand our continued attention.