13 Most Deranged Serial Killers of All Time

When you think of psychology, the first thing that comes to mind might not be serial killers.

Yet, psychologists have long tried to understand why some people become serial killers. Is there a genetic component? Is the environment in which the person grows up more to “blame” for their behaviour? Or is it a combination of factors that turns some people into terrifying killers?

While every case is different, psychologists have tried to point to a variety of factors that might mold someone into a serial killer. It is important to note that there is no particular cause of serial killing, but the traits below tend to be common amongst serial killers:

  • There are biological, social, and psychological underpinnings of this behaviour.
  • People that become serial killers are often intrinsically motivated by reasons they consider to be important.
  • Serial killers occur amongst a variety of demographic groups, including people of different races, genders, ages, and religions.
  • Serial killers who are motivated by sex typically begin to sexualize violence during childhood development.

And while these traits appear to be common, there is no blueprint for what makes a serial killer, nor is there a certain set of experiences that can be pointed to as definitively creating a serial killer.

As such, the study of serial murderers is both highly important and extremely fascinating. The job of a psychologist is to study human behaviour, learn how to describe and explain it, predict it, and then control it. This is true whether a psychologist is working with a client to help them overcome depression, anxiety, or a phobia, and it’s true of psychologists that study serial killers, too. The goal is to figure out why this behaviour occurs so that it can be controlled.

The difficulty, of course, is that serial killing is the result of many different complex processes and experiences. It is a behaviour that one could argue will never be controlled – it’s not as though decades of psychological research are likely to pinpoint a gene that predisposes someone to engage in serial killing.

Instead, psychologists have to rely on research, studies, and interviews with convicted serial killers to try to connect the dots – some of the dots, anyway – to see what they can learn about why serial killers develop.

There are plenty of terrifying serial killers that have stolen newspaper headlines over the years, and some of them have been studied by psychologists seeking answers about the causality of serial killing.

What psychologists have learned from their studies can perhaps be boiled down to one horrible truth – under the right conditions, anyone can become a serial killer.

The serial killers discussed below, though, aren’t just anyone. They are some of the most horrifying individuals to ever walk the earth.

List of the Worst Serial Killers in the World

Ted Bundy (1946-1989)

You don’t have to be American or have been around in the 1970s to know the name, Ted Bundy.

Bundy is easily one of the most deranged serial killers (not to mention kidnappers, rapists, burglars, and necrophiles) of all time. His modus operandi included kidnapping his female victims, raping them, and then dismembering them. He often kept their heads as souvenirs.

Before he was executed in 1989, Bundy admitted to kidnapping and murdering 30 women, though this number is almost certainly much higher.

Harold Shipman (1946-2004)

Nicknamed “Doctor Death,” Harold Shipman is thought to be responsible for murdering 218 of his patients between 1972 and 1998. In reality, the number of people he murdered is likely much higher.

As a practising physician, Shipman had easy access to potential victims, which is why he was able to be such a prolific killer without raising suspicion.

However, because Shipman was involved in so many cases in which patients died, people eventually began to suspect foul play. Most of his victims were elderly women, whom he said had died in their sleep. But many of these women died during the day, which struck some as odd. Additionally, Shipman asked for an unusually large number of cremation certificates, which caught the attention of an undertaker who reported the odd circumstances of the cremations.

Eventually, Shipman was convicted in 2000, but only after a victim’s daughter reported that he had tried to write a will for the victim that would name him as the beneficiary. He died by suicide in prison in 2004.

Andrei Chikatilo (1936- 1994)

Between 1978 and 1990, the Russian serial killer Andrei Chikatilo sexually assaulted, murdered, and mutilated more than 50 young women and children. Chikatilo killed his victims by stabbing and slashing them with a knife. One of the youngest was nine years old.

Chikatilo later admitted that he was only able to achieve orgasm by stabbing women, a fact which made it difficult for him to resist his strong urges to kill.

Chikatilo was nicknamed the “Butcher of Rostov,” the “Red Ripper,” and the “Rostov Ripper.” Though he confessed to a total of 56 brutal murders, he was tried for 53, sentenced to death, and executed by firing squad in 1994.

Jeffrey Dahmer (1960- 1994)

No list of the most deranged serial killers would be complete without Jeffrey Dahmer.

Dahmer, known as the Milwaukee Cannibal, was ultimately convicted of murdering 17 young men over a 14 year period. But Dahmer didn’t just murder them. He also raped, dismembered, and sometimes even ate his victims.

During his trial, Dahmer admitted to drilling a hole into his victims’ heads in an attempt to turn them into mindless sex slaves. Although Dahmer likely would have been executed for his crimes, he was beaten to death in prison in 1994.

Albert Fish (1870-1936)

When a serial killer is dubbed “The Brooklyn Vampire,” “The Moon Maniac,” “The Werewolf of Wysteria,” “The Gray Man,” and “The Boogey Man,” it’s almost certain he is thoroughly deranged.

Fish was tried and found guilty of raping, killing, and cannibalizing three children in the early 1900s. However, he claimed that he had murdered more like 100 children, and even boasted that he “had children in every state.”

Especially deranged is the fact that Fish sent a letter to the mother of one of his victims, 10-year old Grace Budd. The letter detailed how he had lured the little girl, strangled her and then cut her into pieces to eat over the course of nine days.

John Wayne Gacy (1942-1994)

There’s deranged, and then there’s the type of deranged that describes the serial killer John Wayne Gacy.

He was nicknamed “Killer Clown” because of his job attending children’s birthday parties and charitable events as “Pogo the Clown.” His occupation gave him easy access to potential victims.

Gacy was convicted of raping, torturing, and murdering 33 teenage boys over a six-year period. He would lure them to his home, kill them via either strangulation or asphyxiation, and then bury them on his property. Gacy was executed in 1994.

Jack the Ripper (Unidentified Serial Killer ∼1888)

Jack the Ripper may be a name that everyone knows, but no one can be certain of his true identity. Whoever he (or she) really was, Jack the Ripper was definitely deranged.

In 1888, Jack the Ripper terrorized the Whitechapel neighbourhood of London by slitting the throats and abdomens of at least five prostitutes and leaving them for dead. Sometimes, he would even remove the woman’s uterus and take it as a sort of prize.

It’s unlikely Jack the Ripper’s true identity will ever be figured out, but “Ripperology” — the study and analysis of the murders — has certainly inspired quite a few “what if” novels and films over the years.

Joachim Kroll (1933-1991)

German serial killer Joachim Kroll murdered at least 14 people, including young children, between 1955 and 1976. After strangling his victims with his bare hands, Kroll would have sex with their corpses and then cut them up in pieces to eat.

Interestingly, Kroll was finally caught after a neighbour complained about a backup in the plumbing. The pipes were clogged with human remains.

When Kroll was arrested, he was in the process of simmering body parts taken from his most recent victim, 4-year old Marion Ketter.

Joseph James DeAngelo (1945-_)

Though his crimes occurred decades ago between 1974 and 1986, Joseph James DeAngelo wasn’t identified as the Golden State Killer until DNA evidence from one of the crimes was used to match with a close relative of DeAngelo’s, which led to his identification and arrest.

Over the course of three separate crime sprees, DeAngelo murdered at least 13 people, raped more than 50, and committed well over 100 burglaries.

One of the reasons why DeAngelo was able to evade identification and capture for so long is because he was a former police officer. His training undoubtedly helped him in planning and executing his crimes while minimizing the physical evidence he left behind.

In fact, he was known to have called some of his victims months before he attacked them so he could learn about their routines to more effectively plan his crimes. In some instances, he even broke into the homes of his victims so he could unlock doors and windows and even leave items like ropes and other ligatures he could use to tie up his victims upon his return.

One of the most chilling aspects of DeAngelo’s crimes is that he often taunted his victims, staying for hours in their homes, ransacking it, eating their food, and threatening to kill their families. In some cases, he targeted couples, with whom he would separate. He would sometimes force the female victim to tie up the male victim. He would then place plates on the male victim’s back so he could hear if the victim tried to move. DeAngelo would then commence with raping the female victim in another room.

DeAngelo was also known to hide in the home, tricking his victims into thinking that he’d left, only to jump out of the shadows. He would often take souvenirs of his crimes with him as trophies to remind him of what he’d done.

Pedro López (1948-)

Pedro López’s deranged killing spree is terrifying enough, but perhaps even more terrifying is the fact that López’s current whereabouts are unknown.

The native of Colombia claims to have raped and killed more than 300 women across Colombia, Ecuador, and Peru. At least 100 of these were tribal women.

In 1980, the “Monster of the Andes” was arrested and led police to the graves of 53 victims between the ages of nine and twelve.

López was found guilty of murdering 110 girls in Ecuador. He also confessed to an additional 240 murders in Peru and Colombia, and was declared insane.

Incredibly, López was released in 1998 for “good behaviour,” and while there are plenty of rumours, no one can confirm exactly where he is today.

Gilles de Rais (1404-1440)

Gilles de Rais was a wealthy knight and lord, a leader in the French army, and a companion-in-arms to Joan of Arc. He was also a totally deranged serial killer.

Between 1432 and 1433, Gilles reportedly sodomized and then murdered (or ordered the murder) of at least 40 children. Many naked bodies of young boys were found at his estate in 1437.

A 1971 biography of de Rais describes the way the knight lured the boys to their deaths. He outfitted them in fancy clothing and provided them with a large meal and lots of wine. Finally, he confronted each boy with the “true nature of his situation” and murdered them.

Richard Ramirez (1960-2013)

For more than a year during the 1980s, Richard Ramirez terrorized neighbourhoods throughout Los Angeles.

Nicknamed “Night Stalker,” Ramirez would break into homes and brutally murder his victims, sometimes raping them first. His victims ranged from the early 20s to a 79-year old women. His weapons of choice included handguns, knives, a tire iron, a machete, and even a hammer.

Ramirez never expressed any remorse for his crimes. He was sentenced to death but died of lymphoma before he could be executed.

H.H. Holmes (1861-1896)

Of all the deranged serial killers on this list, H.H. Holmes might be the one most people are unfamiliar with.

Holmes was a con artist who moved to Chicago in 1885 and began work in a pharmacy. He built a building near the pharmacy that he used as his base for killing his victims – which number anywhere from 20 to 200.

The height of his activity as a serial killer was during the 1893 Columbian Exposition in Chicago. The fair brought thousands of people to the city, and Holmes capitalized on all the newcomers by offering rooms in his building as accommodations for visitors.

Later called the “Murder Castle,” the building Holmes constructed had multiple hidden rooms where he would torture his victims, whom he eventually killed. The building was outfitted with a series of chutes and trap doors that allowed him to easily remove the bodies of his victims from the upper floors and relocate them to the basement, where the bodies were typically burned in a kiln.

Holmes was put to death in 1896 after his conviction for murdering an associate of his, Benjamin Pitezel.