Serial killers are some of the most fascinating and intriguing criminals. Although the definition and ‘criteria’ of a serial killer can vary between different law enforcement agencies and psychologists, the term is typically applied to any person who kills at least two victims with a significant ‘down time’ between the murders. This distinguishes serial killers from mass murderers (who kill at least four people in a short amount of time without any ‘cooling off’ period) and spree killers (who kill at least two people in different locations over a short amount of time, again without any ‘cooling off’ period). Many people mistakenly think that a serial killer has to have the same ‘modus operandi’ and that they target the same types of victims each time and that they always kill people in the same way. However, while many serial killers display some sort of pattern in their behaviour, it’s not always easy linking a series of murders over time to the work of one person. Although serial killers are a relatively rare phenomenon in the criminal world (less than 1% of murders each year are the work of a serial killer), some of the men on this list committed the most notorious and disturbing crimes ever documented.
10. Dennis Nilsen (1945 -)
Full Sutton Prison
The behaviour of some serial killers can be erratic and their crimes show no discernable pattern or identifiable links between victims. However, some serial killers operate with the same methods for years and always target the same victims. Dennis Nilsen is a predatory British serial killer who targeted homosexual or homeless young men. Nilsen always killed in his home and he always convinced his victims to enter the premises with promises of food, shelter or alcohol.
Nilsen served in the British army until 1972 before moving to London and working as a civil servant. From 1978 to 1983 Nilsen killed 15 men and attempted to murder several others. Nilsen strangled his victims until they passed out and then drowned them in a bucket of water. Nilsen would then typically carry out a methodical ritual where he would clean and dress the corpses and leave them in his flat for weeks or even months.
During this time, Nilsen occasionally engaged in acts of necrophilia with many of his victims corpses. When he was finished with his victim, Nilsen dismembered the bodies and either buried the parts under his floorboards, disposed of them discreetly in public or flushed then down the toilet or drain. The latter method proved to be Nilsen’s undoing as one of his final murders resulted in a sewage worker finding small bones and bits of flesh in the drains of the flats where Nilsen was living. When police entered Nilsen’s property, they were hit by the overwhelming smell of decomposing flesh and Nilsen admitted he had two plastic bags full of body parts in his wardrobe. Nilsen is currently serving life imprisonment.
9. John Wayne Gacy (1942 – 1994)
White House photographer/public domain
Dubbed ‘The Killer Clown’, John Wayne Gacy was a terrifying serial killer who targeted young children and teenage boys. Working as a children’s entertainer, Gacy was a well-liked member of the community and he performed at charity events and even in children’s hospitals as the character ‘Pogo the Clown’.
However, before he even committed his first murder in 1972, Gacy had already been convicted of sexually assaulting teenage boys and he had been diagnosed with antisocial personality disorder by psychiatrists. From 1972 to 1978, Gacy murdered more than 30 young victims in his home in Del Plaines, Illinois. Gacy lured his victims into his property with offers of contractor work and then strangled them to death. Police were alerted to Gacy’s activity after he was overheard talking about remodelling work to a teenage employee at his local pharmacy shortly before the teen went missing.
The subsequent surveillance and evidence-building investigation of Gacy eventually resulted in police searching his property and discovering 26 victims buried in the crawlspace of his home. Three other victims were buried in the garden and Gacy also later confessed to disposing of four more victims in the Des Plaines River. After spending 14 years on death row, Gacy was executed by lethal injection in 1994.
8. Albert DeSalvo (1931 – 1973)
Albert De Salvo had a childhood which is typical of many serial killers. DeSalvo found joy in torturing animals from an early age and his father was an alcoholic who violently beat him and his mother. Unsurprisingly, it wasn’t long before the young boy came to the attention of the local police. DeSalvo spent time at a juvenile correction home at the age of 12 for battery and robbery and again aged 14 for stealing a car.
DeSalvo enlisted in the army in 1948 but he was honourably discharged seven years later following allegations he had sexually molested a nine year old girl. Moving to Boston, DeSalvo continued his sexual assaults by posing as a talent scout for a modelling agency and fondling unsuspecting victims as he took their ‘measurements’. Although he was not prosecuted for this crime, he was sent to prison for 11 months for burglary in 1960. Upon his release, the severity of DeSalvo’s crimes dramatically escalated and he began raping and murdering women. Nicknamed the ‘Boston Strangler’, DeSalvo broke into his victim’s apartments and sexually assaulted them before strangling them to death with their clothing.
DeSalvo killed 13 victims but it is estimated that he committed more than 300 sexual assaults in just two years. At first, police did not believe the murders had been committed by the same serial rapist (who they had named “the Green Man” because he always dressed in green), but DeSalvo admitted to all of the crimes when he was finally arrested in 1964. DeSalvo was sentenced to life imprisonment, but he was stabbed to death in prison in 1973.
7. The Zodiac Killer (unknown)
San Francisco Police Department
The work of some serial killers cause mass panic as the public wait in fear for the murderer to strike again. Operating in the northern California region, the Zodiac killed 7 victims (four men and three women, all aged between 16 and 29) between 1968 and 1972. During this time, the Zodiac sent bizarre, cryptic letters to the press in which he boasted about his crimes and taunted the police. The letters stopped in 1974 and the Zodiac was never heard of again. Although police, investigators and amateur sleuths have their suspicions about the true identity of the Zodiac, the killer was never found.
6. H. H. Holmes (1861 – 1896)
Some serial killers are known for the way they meticulously plan their crimes and murders but few, if any, match the methods of H. H. Holmes. One of America’s earliest documented serial killers, Holmes’ criminal career began with insurance fraud and shady dealings. After a string of failed marriages and a period of travelling across America, Holmes moved to Chicago in 1886 and, while working as a pharmacist, purchased a three-story block which was dubbed the ‘Castle’.
Chicago was busy planning for the World Fair of 1893 so the city was a hive of activity in the years leading up to the huge event. This meant that Holmes was able to operate without notice. Advertising his building as a hotel for the upcoming event, Holmes adapted the Castle into a labyrinth. Misshapen hallways led to bricked up doorways, most of the rooms had no windows and some staircases led to nowhere. Holmes even employed different teams of builders to ensure that no one knew the final layout of his ‘hotel’.
In 1888, Holmes began killing guests, employees and anyone else he could lure into his building (he would often meet young impressionable girls coming in at the city’s central rail station and offer them employment). Although he only confessed to 30 murders when he was eventually caught, investigators estimate that Holmes killed at least 200 people in his “Murder Castle”. Holmes killed many of his victims by gassing them in their rooms or suffocating them in a large soundproof safe next situated next to his office. He would then use trap doors to drop the corpses to the basement where he stripped them of their possessions and disposed of the corpses by cremation or acid. Sometimes he would remove their flesh and turn them into skeleton models to sell to medical schools. Holmes also claimed the life insurance policies of many of his victims. Holmes was found guilty and was executed in 1896.
5. Jeffrey Dahmer (1960 – 1994)
One of the most notorious killers who ever lived, Jeffrey Dahmer confessed to acts of murder, cannibalism and necrophilia. In 1978, Dahmer committed his first murder at the age of 18 when he picked up a male hitchhiker for sex and killed him afterwards with a dumbbell. Nine years later, Dahmer started killing again. He typically targeted gay bars close to his home so he could spike the drinks of his victims and easily bring them back to his house. Dahmer strangled his victims and then completely dissected and dismembered their corpses. Just a few of Dahmer’s disturbing acts involved drilling holes into a victim’s head and pouring acid into their skull, keeping the skulls, genitals and organs of people he had killed as ‘trophies’ and freezing body parts for later consumption. Dahmer killed 16 people between 1987 and 1991 (near the end of his murder spree, he was sometimes killing at least one person a week) before he was finally caught. Dahmer was sentenced to life imprisonment following his trial in 1992, but he was he murdered by a fellow inmate in 1994.
4. Ted Bundy (1946 – 1989)
Florida Department of Corrections
Like many serial killers on this list, no one ever suspected that Ted Bundy was capable of the heinous acts he committed. Approachable, friendly and very intelligent, Bundy knew how to use his personality and good looks to charm his victims into a false sense of security. Sometime after dropping out of law school in 1969, it is believed that Bundy claimed his first victim (even after his arrest he refused to talk about some of his earlier crimes).
Always on the move and leaving little to no evidence behind, Bundy primarily targeted young women. Bundy either broke into his victim’s homes or abducted them in plain sight (sometimes with a ruse, like wearing a fake sling or cast on his arm and asking for sympathetic help). Bundy then bludgeoned or strangled the young women and disposed of their corpses (police never found the bodies of many of his victims). He also confessed to sexually assaulting his victims as well as committing necrophilia on some of their corpses. Police attributed at least 30 murders across seven states to Bundy (the death count may have been much higher) and he was executed by electric chair in 1989.
3. Albert Fish (1870 – 1936)
Albert Fish is one of the most disturbing individuals in criminal history. Fish confessed to molesting, castrating, murdering and even eating dozens of young children. From a young age, Fish was obsessed with sadomasochism and subjected himself to acts of self-harm and mutilation (an X-ray taken after his arrest revealed that Fish had pushed more than two dozen needles into his body, mostly around his pelvis and groin region). When his wife and the mother of his six children ran off with another man in 1898, Fish’s twisted behaviour escalated and he started hearing strange voices and suffering from hallucinations.
He claimed his first murder victim in 1928 by luring 10 year old Grace Budd into a derelict bungalow. Fish strangled and dismembered Budd and cooked some of her parts in a stew. Working as a handyman, Fish moved from state to state preying on young victims who were typically from poor backgrounds (Fish stated that these types of parents “wouldn’t make a fuss” if their children went missing). He was finally caught in 1935 when police traced a sick gloating letter sent to Budd’s parents back to Fish’s address. Confessing to years of heinous acts, Fish was given the death penalty and executed by electric chair in 1936.
2. Harold Shipman (1946 – 2004)
Not all serial killers leave behind a grisly trail of corpses. Harold Shipman is one of the most prolific serial killers in history but he went completely unnoticed as he killed more than 230 people over the course of two decades. Shipman began practising medicine in Yorkshire, England in 1974 but it wasn’t long before he ran into the wrong end of the law. Shipman was found guilty of forging prescriptions for his own use in 1974 but he was able to continue working as a medical practitioner under supervision. Shipman was considered ‘rehabilitated’ and in 1977 he became a GP in Manchester.
Shipman claimed his first victim in 1984 when a 76 year old woman came to his surgery complaining of cold-like symptoms. The next day, Shipman claimed that he found the elderly patient dead in her bed during a home-visit. Over a 20 year period, Shipman targeted mostly elderly females and injected them with lethal doses of drugs under the guise that he was helping them get better. In 1998, Shipman was reported to the police by a local undertaker who raised suspicions of the high death rate of the doctor’s practice, and the subsequent police investigation charged Shipman with 15 murders and 1 count of forging a will. Shipman was found guilty and sentenced to life imprisonment with the recommendation that he never be released. He killed himself in his prison cell in 2004. An inquiry launched after his trial found that Shipman had killed around 250 of his patients.
1. Luis Garavito (1957 -)
Government of Colombia
Luis Garavito has claimed more victims than any other serial killer in history. Few details are available about his early life but the Colombian-born killer admitted during his trial that his father physically beat him as a child and he was sexually assaulted as a young boy. Between 1992 and 1999, Garavito moved from town to town in Colombia murdering young children aged between 6 and 16. Garavito targeted children from poor backgrounds as he found it easier to gain their trust with promises of small gifts or money. Garavito would walk his victims to a secluded area before he raped them and slashed their throats.
After his arrest, Garavito was charged with the murder of 138 children but it is suspected that he could have killed more than 300. The maximum prison term in Colombia at the time of Garavito’s conviction was 30 years and he has been helping police locate the bodies of his victims from prison (which usually helps reduce a sentence in Colombia). However, it is unlikely he will ever be released as investigators continue to find the body of victims he did not admit to killing at his trial which could lead to further convictions against Garavito.