With countless true crime-inspired documentaries, films, TV shows and podcasts hitting mainstream audiences in recent years, it would be fair to say that we love the genre. With the success of releases such as The People vs O. J. Simpson, Making a Murderer and Mindhunter, the public’s interest in the cases behind these shows only seems to be growing.
But what about the real-life men and women who commit the horrific acts that have captured the morbid imaginations of millions of true crime fans. What goes into the making of a real serial killer and what are the most common traits shared by the world’s most notorious killers?
Serial killers are 12 times more likely to be men than women.
The majority of the serial killers on our list are male, with just three of them being women. Of these women, it was only Aileen Wuornos who acted without a male accomplice. The other women are Rosemary West, who worked with her husband, Fred West, and Myra Hindley who worked with Ian Brady.
Pisces and Sagitarius are the most common star signs among serial killers. Air star signs account for almost a third (32.5%) of these serial killers.
While it may seem like a tenuous link, some star signs do appear to be more common among the most notorious serial killers, with Pisces and Sagittarius topping the list, while none of the serial killers we looked at are Cancer or Taurus signs.
37.5% of these serial killers are American, compared to 17.5% Brits
While we only looked at a small sample of killers, those we did research were predominantly from the US and the UK. 15 of the serial killers are American while seven are British.
Serial killers are twice as likely to work alone than to have an accomplice
Out of the 40 serial killers, at least 27 of them worked alone, with 13 having accomplices, but two of those 13 claimed to have accomplices although these claims have not been proven.
Serial killers stand taller than the average person, are 1.8 times more likely to have brown eyes than blue eyes and are 9 times more likely to have dark hair than light hair.
While it was not possible to find reliable data for all the killers on the list, we have taken the height, eye colour and hair colour where it is available.
The tallest killer was Edmund Kemper who stood at a towering 6ft 9in, with Charles Manson at the other end of the scale at just 5ft 2in according to many reports. The average height of all the serial killers was 5ft 10in
The average height of the male serial killers was 5ft 10in and the average height for female killers was 5ft 5in, both of which are taller than the global average.
Those with brown eyes were the most common on the list with 25 killers having dark eyes, whereas just 14 had blue eyes.
Dark hair was also most common with 35 killers having black or brown hair, just three with blonde hair and one with red hair.
30% of serial killers experienced a head injury before their killings began
Some experts have linked head injuries with violent behaviour, so these can often be found in the history of serial killers. In fact, across our list, 12 killers suffered head injuries prior to their killings. These include Fred West who spent seven days in a coma after suffering a fractured skull aged 17 and David Berkowitz who sustained three separate head injuries before the age of eight
Half of these serial killers were married
Surprisingly, many serial killers have managed to maintain a seemingly normal family life, with 20 of those on our list known to have been married at some point in their lives. Dennis Rader, for example was married for over 30 years and seemed to most to have a happy and normal family life, only divorcing from his wife after being arrested for the murders of 10 people.
Just as many killers have maintained relationships, a number of them had children of their own with the likes of Rosemary and Fred West, Harold Shipman and Charles Manson having a number of children, Rosemary West being the mother of eight children in total.
20% of these serial killers have served in the military
The employment history of serial killers seems to be particularly varied, with many killers holding a number of menial jobs rather than progressing in one career. Some of the standout jobs of serial killers include Harold Shipman who was a GP, giving him access to his victims and Mikhail Popkov who used his status as a police officer to gain the trust of some of his victims.
Eight of the killers on the list are known to have served in the military at some point in their history, including Dennis Nilsen and Gary Ridgway.
17.5% of these serial killers killed before leaving their teenage years, 67.5% of these serial killers killed before hitting 30 and 20% of these serial killers chose July as the month for their first murder
For some of these killers, it is difficult to tell when they first took a life. However, for others, we know exactly when they claimed their first victim. Looking at these individuals, we discovered the time of year most common for their first murder. A total of eight killers committed their first murder in the month of July, followed by four in January and two each for June, November and December. Amongst the July killers were the likes of Gary Ridgway, Fred West and Charles Manson.
When we look at the age at which these killers took their first life, we can see just how young some of them were. Pedro Rodrigues Filho who killed at least 71 people was just 14 at the time of his first murder. He is followed by Edmund Kemper who was 15 and Rosemary West who was 17. The average age of these killers at the time of their first murder is 27.5.
Over 1,600 people dead at the hands of just 40 of the worst serial killers
The number of victims between these 40 killers is shockingly high, with a total number of roughly 1,634 victims. Harold Shipman was the most notorious killer with 218 victims to his name, although, it is thought that this number could be as high as 250.
2 in 5 of these serial killers escaped justice for more than 10 years
While some killers were caught within hours of their killings, such as Richard Speck, others terrorised communities for decades. Pedro Rodrigues Filho was active for the longest with his crimes spanning 36 years. This is followed by Samuel Little with 35 years and Pedro López with 33 years.
20% of these serial killers were executed for their crimes
As these serial killers come from all over the world, their sentences differ hugely. In total, 14 of them were sentenced to death, although this was commuted to life in prison for four of the killers from the United States. 21 were sentenced to life imprisonment or equivalent, with the longest sentence being given to Moses Sithole who was given 2,410 years in prison.
Eight of the killers were executed for their crimes, including Ted Bundy and John Wayne Gacy. 14 others have died while serving their sentence, while Fred West died by suicide before conviction and Dean Corll was shot and killed by an accomplice before authorities caught up to him.
While 13 are currently still serving their sentences, two have been released with the whereabouts of Pedro López currently unknown.
Along with some of the best-known serial killers, we took a list of the most notorious serial killers by the number of victims from Wikipedia.
We used Wikipedia, Murderpedia, Murder Mile Tours amongst other news sources to find information about each person on our list, giving us data about everything from their height to details about their employment. While we have sought out accurate data, it is important to note that in many of these cases, the real details remain unknown, so we have taken details of convictions or most likely number of victims when it is not possible to provide a firm number.
While Richard Speck is classified as a mass murderer, he was included in the list due to his notoriety.