Serial Killers Research: What Makes A Serial Killer, How To Spot One, And Much More

Let’s kick things off by explaining what a serial killer represents.

Well, it’s a person who kills 3 or more people with a “cooling down” period (a month or so) between the killings. The killings are often driven by pleasure or psychological thrill.

Serial killers lack guilt, empathy, and remorse. They’re often egocentric people with specific traits which overlap with the characteristics of psychopaths. This is why people confuse killers with psychopaths and vice versa. However, not every psychopath is a serial killer. And vice versa.

Moreover, serial killers wear a “mask of sanity” which helps them blend into society as well as hide their psychopathic tendencies. Thus, they appear normal and even charming.

Serial Killer Research shows some traits that are common but perhaps the most disturbing thing is there is no predictable pattern.

What Makes A Serial Killer?

What Makes A Serial Killer

Are serial killers born or made? This is one of the oldest questions in many different studies such as law, philosophy, theology, and of course, criminology.

According to studies, they’re a mix of both nature (genetics) and nurture (environmental factors). A book by Peter Vronsky, named “Sons of Chain: A History of Serial Killers from Stone Age to the Present”, examines why some individuals become serial killers, and others don’t.

If you’re interested in learning about serial killers in-depth, definitely check that book. Vronsky examines how people’s understanding of serial killers – named “monsters” has evolved before modern psychology has appeared. He also answers the question: what makes a serial killer?

Studies have revealed that most serial killers have survived some type of childhood trauma like sexual or physical abuse, emotionally distant or absent parents, family dysfunction, etc. If you take a look at some of the serial killer cases, you will notice that trauma is a recurring theme.

And as a result of this childhood trauma, they suppress their emotional response instead of learning the right responses to trauma. Therefore, they never develop other emotions such as empathy, which is why they find it hard to empathize with others in the future.

However, not all kids who have experienced some type of trauma turn into killers when they grow up. In fact, some studies have discovered that specific genes can predispose individuals to violence. I also want to mention that most serial killers were separated from their mothers as children.

It’s also suspected that most serial killers fear relationships and crave control over others. They’re often loners who decide to kill others to eliminate the chance of another humiliating rejection.

Some serial killers want the fame and attention that mass media can give killers. Another interesting fact about serial killers is that only 1 in every 5-6 serial killers is a female and female killers’ psychopathology is different from male killers’ psychopathology.

Furthermore, research on female serial killers is hard because there aren’t so many female serial killers. Or perhaps they’re better at hiding their crimes. What do you think? Drop a comment and let’s keep the conversation going below!

People who have studied female killers say that they’re less likely to leave any evidence behind including bodies. They’re quiet killers with a longer “killing career” and apparently, they’re better at covering their tracks than men.

They’re also less interested in torture and mutilation. However, just like male serial killers, they’re driven by psychological thrill or the need for control over their victims, so they rarely kill for sexual gratification. They usually kill for control. However, they may apply it through sexual acts.

The 4 Main Types Of Serial Killers

The 4 Main Types Of Serial Killers

The 4 main types of serial killers include thrill-seekers, visionary killers, mission-oriented, and power and control seekers. As you can clearly notice, they’re all based on the type of crime they commit.

Since 1980, there have been over 220,000 unsolved murders in the US. And you can’t help but wonder if serial killers are responsible for the majority of these murders. Since 1900, there have been about 3,000 identified serial killers in the US. And they’ve collectively murdered approximately 10,000 people.

About 32% of serial killers killed people for lust, thrills, and power – they killed for enjoyment while 30% committed murders for financial gains. About 18% killed their victims in anger and 6.3% killed to boost a criminal enterprise. Lastly, little under 1% of killers committed killings under the pressure of a cult.

The favorite murder weapon for 42% of serial killers was a gun. Only 2% preferred axes while 6% utilized poison. About 52% of serial killers were white, 40% were black, and 6.7% were Hispanic. Moreover, men outnumbered women by a factor of 10, which means there are more male than female serial killers. 

Have you heard of Samuel Little? If not, you’re lucky. He was a transient former boxer and criminal who passed away recently. He was serving time for only 2 murders but has confessed to over 93 killings.

I’m a fan of the true-crime community that covers unsolved crimes on YouTube. And I can’t help but wonder how many of the unsolved murders and missing person cases were the work of serial killers like Samuel Little and will probably never be solved.

How Do Serial Killers Choose Their Victims?

Sadly, you can’t predict who will catch the eye of a killer. No one knows for sure what makes a killer pick a specific person as their victim, especially a serial killer. When asked about this, serial killers usually give different answers regarding their choice of victims and reasons for their crimes.

However, the most common belief is that serial killers want to feel full control over other people. Jeffrey Dahmer, for example, said that he was driven by the need for control over his victims in one of his many interviews. Experts say that most serial killers have a vision of their perfect victims.

And if you take a closer look at some of the cases of serial killers, you will notice that their victims share something in common like race, physical traits, gender, or something else. However, it’s difficult to find people who meet all of their criteria, so they look for individuals with similar traits.

Although most serial killers feel a strong urge to kill, they’re still very cautious individuals who won’t pick a victim unless they’re certain they will be able to lure in, overpower, and kill the person without getting caught. This is why their first victim is usually a homeless person. Or a sex worker.

Are There Serial Killers All Around The World?

Of course! Serial killers have been reported on 6 continents.

It’s widely believed that Western countries including the US tend to have more known serial killers than non-Western countries.

However, experts theorize that this is likely because of better law enforcement efforts and more media coverage, rather than a real increased prevalence of serial killers.

The Psychology of Serial Killers

The Psychology of Serial Killers

The general public together with law enforcement agencies and criminal psychologists have been trying to find out what makes serial killers commit their horrible crimes.

Most “regular” people could never torture and murder other human beings which is why people wonder if serial killers suffer from severe mental illness that affects their perception of reality.

Well, some serial killers did appear to experience psychotic breaks that triggered their killings. But most serial killers have rarely been found criminally insane, which is why the “non-guilty due to the reason of insanity” defense rarely works for them. They can tell the difference between right and wrong.

They just don’t care! In fact, the most common psychological features among serial killers include a lack of empathy. They’re incapable of remorse and show no regard for social norms and laws.

Thus, most serial killers share antisocial behavior. They also have a strong desire to revenge themselves against society or individuals by committing unspeakable murders.

Are Serial Killers Mentally Ill?

It depends on the serial killer. Some serial killers have shown symptoms of psychosis, while others have been diagnosed with severe bipolar disorder.

Most serial killers aren’t considered mentally ill enough to be proved legally insane. Rather, the majority display signs of sociopathy or psychopathy.

Are All Serial Killers Psychopaths?

Most serial killers show antisocial tendencies like lack of empathy and remorse, disregard for the rights of others and laws, etc.

Therefore, many of them meet the criteria for either psychopathy or sociopathy. Some serial killers have been diagnosed with schizophrenia, psychosis, or other personality disorders instead of psychopathy or in addition to psychopathy.

However, not every psychopath becomes a serial killer. On the contrary, they become a high-functioning member of society.

Do Serial Killers Have A High IQ?

Usually, movies such as the “Silence of the Lambs” often portray serial killers as “evil geniuses”, most of them aren’t as smart as people think.

On the contrary, they either have a low or average IQ. Only a small number of serial killers have demonstrated a high intelligence.

What’s The Difference Between Male And Female Serial Killers?

Although most serial killers are men, women have also committed horrible murders throughout history. In fact, women make up to 15% of serial killers, according to some experts.

Furthermore, stereotypes of females as submissive and nurturing probably fuel the false belief that all serial killers are men.

As for the differences, female serial killers aren’t usually driven by sexual motivation. They kill for profit, the need for control over their victims, and psychological thrill.

They’re also less messy and their favorite weapon is poison. Female serial killers often commit serial killings in a tandem with a male killer.

Does Childhood Trauma Create Serial Killers?

Does Childhood Trauma Create Serial Killer

Past studies have discovered a possible link between childhood trauma including mental, physical, and sexual, and serial killers. Most killers often come from unstable homes and show signs of voyeurism and sadomasochism from a young age. Also, approximately 90% of serial killers are men.

For instance, Charles Manson, a serial killer who murdered 7 people over the course of 2 nights in 1969, said he would encourage violence against other kids even at school in one of his interviews. He was also neglected and abused as a child. Ted Bundy, on the other hand, has a pretty normal childhood.

Therefore, it’s hard to say that childhood trauma makes serial killers. Most serial killers were abused as kids. However, not everyone who has a terrible upbringing turns into a serial killer. Furthermore, despite popular belief, serial killers don’t belong to one specific race. They span all racial groups.

How To Spot A Serial Killer: 5 Key Traits To Look Out For!

Most serial killers wear a “mask of sanity”, however, thanks to criminologists, psychologists, and modern technology who have identified traits of serial killers, you can recognize a possible serial killer.

Dr. Elizabeth Yardley, the Director of the Center for Applied Criminology at Birmingham City University, has underlined the following 5 key traits of serial killers, so take a closer look and stay vigilant.

Obsession with power

Serial killers have an obsession with power and control, even when they’ve been arrested. And because of that, they often hold back parts of important information to maintain power over the situation as well as gain some attention.

Take Ian Brady for example. He was a serial killer convicted for murdering 5 children together with Myra Hindley, between 1963 and 1965. Brady withheld the location of some of his victims’ bodies from police to assert control and power.


The need to please along with apparent vulnerability has been utilized effectively consistently by serial killers as a way of covering a sinister, manipulative, and controlling personality.

Some of the most notorious serial killers have a scary ability to manipulate others. They always press the right buttons to present themselves in a better light. They pass the blame for their actions, utilizing hot-button problems of the day or medical psychological research to try to explain their actions.

For instance, Harold Shipman utilized his position as a medical expert to manipulate people into various treatments that eventually killed them while playing a caring member of society.

Bragging about crimes

Bragging about crimes

Most egotistical serial killers usually can’t help but brag about the murders they’ve committed, whether it’s aimed at the next victim, their accomplices, authorities, or just themselves.

For instance, Brady and Hindley frequently visited the burial sites on Saddleworth Moor. They even took pieces of the landscape as a souvenir of their crimes. So, thanks to their stupid moves, they incriminated themselves and helped the police locate the bodies of their 3 victims on the Moor.

Another example is Trevor Hady. He was a convicted serial killer from the UK, also known as the “Beast of Manchester”. Hardy killed teenage girls during the 1970s and bragged about it to his younger brother, which led to his arrest. As you can notice, serial killers aren’t the brightest people.

Superficial charmers

Serial killers can easily read other people. Meaning, they can recognize their emotions, weaknesses, and vulnerabilities to convince them into doing things they usually wouldn’t, experts say.

They will usually push others to the side and take control of a situation with a mix of common sense and compliments. Take Ted Bundy for example. He was considered a real charmer by the ladies.

In 1989, shortly before his execution, he confessed to approximately 30 killings in 7 states between 1974 and 1978. However, it’s believed he killed many more. What blows my mind is that many females found him attractive and charming even after he was convicted for his murders. How crazy is that?

Bundy kidnapped, raped, and killed women after posing as a person of authority and earning their trust. And still, he was usually described as this handsome, charismatic, and charming person.

Average Joe

At first glance, many serial killers look like a pillar of the community, however, it’s only a tactic of gaining trust that they can abuse in the future.

This tactic has allowed serial killers to get away with many deviant things behind closed doors. Take Fred and Rose West for example. They looked like a normal family.

But the couple was further from normal. They tortured, raped, and murdered women and girls between 1976 and 1987. They’ve murdered at least 12 people including family members. They even buried some of their victims in the garden of their home in Gloucester, United Kingdom.

Another good example is John Wayne Gacy, also known as the “Killer Clown”. He was a politically active member of society in Chicago, US. He even performed as a clown at different events and parties. At first glance, he appeared like a hard-working and successful person.

However, behind the scenes, he raped and killed teenage boys. As you can see, serial killers can appear pretty ordinary which is far from the truth.

Final Thoughts

Final Thoughts

What I’ve concluded from this deep dive into the world of serial killers is that they’re mysterious people who do what they do because of different reasons. And it’s still not clear if they’re born or made.


Serial Killers Research

In my personal opinion, it’s a little bit of both. I also believe that childhood trauma has some part in their future behavior. However, I would like to hear your opinion and theories in the comments below!