Many believe serial killers are naturally intelligent, however, the majority are just like everybody else – scoring between 70 and 130. Those considered “organized serial killers” who kill methodically, like John Wayne Gacy, Dennis Rader or Ted Bundy, have an average I.Q. of 113. Those who are less organized, such as serial killers Aileen Wournos and Richard Ramirez, who would kill at random, possessed a low IQ of just 81 – 95.
These following serial killers have an I.Q that is considered at genius level – above 140. Only 5% of the population score at genius level and these killers used their gift in the most sinister way possible.
7. Edmund Kemper – 145
Edmund Kemper is one of the few serial killers who has an IQ which is considered to be at genius level. Psychological tests found his IQ had a score of 136 but in later tests his score was found to be 145.
Standing at 6 ft 9 in (2.06 m) tall, weighing over 300 lbs (140 kg) and having an IQ at genius level, allowed him to overpower his victims both mentally and physically. Investigators labeled him a “natural born killer.”
Also known as The Co-ed Butcher, Kemper abducted and murdered several women in the early 1970s in Santa Cruz, he also murdered both of his grandparents and his own mother. His total victim count is believed to be 10 and he often kept the severed heads of his victims for several days before disposal. He eventually turned himself in and even requested the death penalty for his crimes.
As capital punishment was temporarily suspended in California, he instead received eight life sentences and he has since been incarcerated at the California Medical Facility. He is now 67-years-old.
6. Jeffrey Dahmer – 145
Jeffrey Dahmer, known as the Milwaukee Cannibal, murdered and dismembered seventeen men and boys between 1978 and 1991. He would strip the bodies of flesh and store these parts in his fridge at home so he could consume them later. The public was so outraged, he stood trial behind a sheet of bullet-proof glass – he also had to be brought to court in a wheelchair as the shackles on his ankles were too heavy for him to walk.
His I.Q had been previously tested during a term at Ohio State University, he was at genius level with a score of 145. Although shortly afterward, he dropped out of studying as his alcoholism had taken over his life.
In 1991, police officers found a man wandering around the street wearing handcuffs. When they investigated they found the victim had been drugged and were then led to Dahmer’s apartment where they found his refrigerator full of various body parts.
Dahmer confessed to killing and dismembering all 15 of his victims and during the trial, he pleaded guilty but insane. If found guilty by insanity he would have been sent to a mental institution instead of prison where he could have petitioned for release just six months later.
The jurors were then asked to consider these following questions: “Did Jeffrey Dahmer suffer from mental illness? And if so, did he have “the capacity to appreciate the wrongfulness” of his conduct or “the ability to conform” to the law?” Only two of the twelve jurors considered Dahmer insane. On November 28th, 1994, a fellow inmate at Columbia Correctional Institution beat him to death.
5. Andrew Cunanan – 147
In 1997, Andrew Cunanan murdered at least five people during a three-month period – one of his victims was fashion designer Gianni Versace. He was 27-years-old when he became the 449th fugitive to be listed by the FBI on their most wanted list.
During school, his teachers found him bright and very talkative, testing with an I.Q. of 147. However, as a teenager he became a prolific liar, spreading a lot of tales about his family and personal life.
When he was 19-years-old, his father went on the run to avoid arrest for embezzlement and that same year, his mother found he was gay. Infuriated his mother had uncovered his secret, he threw her against a wall – dislocating her shoulder.
He was later treated for having an antisocial personality disorder and a personality disorder characterized by an abnormal lack of empathy – which today would be known as psychopathy. He attended the University of California, San Diego, where he majored in American History. During his studies, he visited high-class gay bars and sold sex to wealthy older men.
After murdering his friend Jeffrey Trial, he killed three others before shooting Gianna Versace. Eight days later, he shot himself in the mouth with a semi-automatic pistol he had stolen from his murdered friend, Trial. He was cremated and his remains are at the Holy Cross Catholic Cemetery in San Diego, California.
4. Carroll Cole – 152
Serial killer Carroll Cole took the lives of sixteen victims. As a young boy, his mother would often engage in drunken sex with strangers, she would then beat him afterward threatening more violence if he dared to tell his father.
He was often bullied at school because of his first name, he claimed one of his earliest memories was blacking out and when he came round he found a strangled puppy next to him. He would often fantasize about killing his own mother. At high school, he was ranked as a genius – scoring 152 on an I.Q test. Although due to his unruly behavior he never achieved more than a D+ on any exam.
His first murder was in 1946, he was swimming with friends at Richmond yacht harbor and he held one of his friends under water until he died. The crime was regarded as an accident until Cole confessed to killing his friend years later. In 1960, he attacked two couples parked in cars on a lover’s lane and not long after he called the police in Richmond, California, and told them that he could not stop his fantasies about strangling women.
He was admitted to Stockton State Hospital and one psychiatrist wrote: “He seems to be afraid of the female figure and cannot have intercourse with her first that must kill her before he can do it.” The same psychiatrist approved his release three years later.
His killing spree then continued for nearly nine more years. He claims to have murdered at least 14 women although he believes there could be more as often he was drunk when he committed the crimes. In October 1984, Cole was sentenced to death and his last words were: “Thanks, Judge” before he was executed by lethal injection at Nevada State Prison on December 6th, 1985.
3. Charlene Gallego – 160
Charlene Gallego, alongside her husband Gerald Gallego, terrorized Sacramento, California during the late 1970s as they kidnapped 10 victims, mostly teenagers, whom they kept as sex slaves before killing them.
Charlene was an incredibly gifted child, quiet and polite – she scored 160 on an I.Q test. Then by the time she was a teenager, she had become sexually promiscuous and started heavily drinking. She had been married twice, leaving her second husband because he was “too boring”.
When she met Gerald, the pair fell insanely in love with each other and also with their love for rough sex, within a week of meeting they both moved in together. One night, Gerald bought home a 16-year-old dancer and they had a threesome together under the agreement that the women were not allowed to touch each other.
When the rules were broken, Gerald threw the young dancer out the window of the home and beat Charlene. They then began their spree of kidnapping young women to keep as sexual slaves before killing them.
In 1984, Charlene pleaded guilty to murder and she was tried in Nevada. She received a sentence of sixteen years and after her release from prison, she moved to Fair Oaks, California, and changed her name to Mary Martinez.
2. Ted Kaczynski – 167
Ted “Unabomber” Kaczynski was an American anarchist, mathematical prodigy, and domestic terrorist. He grew up in Evergreen Park, Illinois and was named a child prodigy, excelling academically from an early age – he has an I.Q of 167.
Aged just 16-years-old, he was accepted into Harvard University where he earned an undergraduate degree and later he gained a Ph.D. in mathematics from the University of Michigan. At 25-years-old, he became an assistant professor at the University of California, Berkeley but he resigned just two years later.
In 1971, he moved to a remote cabin in Lincoln, Montana without electricity or running water, where he lived a reclusive life while learning survival skills. Between 1978 and 1995, Kaczynski began a nationwide bombing campaign against people involved with modern technology. He would plant or mail homemade bombs, which killed three people and injuring 23 others.
Kaczynski sent an anonymous letter to The New York Times on April 24th, 1995 promising “to desist from terrorism” if the Times or the Washington Post published his article: Industrial Society and Its Future or the “Unabomber Manifesto”).
He argued that the bombings were extreme but necessary to attract attention to the erosion of human freedom necessitated by modern technologies requiring large-scale organization.
After the manifesto was published, his sister-in-law and his brother recognized his style of writing causing them to tip off the FBI. Kaczynski then entered a plea agreement and he was sentenced to life in prison with no possibility of parole.
1. Rodney Alcala – 170
Rodney Alcala was sentenced to death in California in 2010 for killing five people during the late 1970s – although the real victim count is believed to be much higher, some suspecting the number could actually be around 50.
One investigator called Alcala “a killing machine”; he would toy with his victims, strangling them until they lost consciousness, then waiting until they revived, repeating the process until they eventually died.
Investigators found more than 1,000 photos taken by Alcala, both of women and teenage boys, in sexually explicit poses. It has been speculated that many of the photos were of his additional victims. In 1978, in the middle of his killing spree, he took part on the show “The Dating Game”.
During his first trial for the murder of four women, his high IQ of 170 managed to allow him to outwit prosecutors and both rulings were overturned due to technicalities. That was until DNA testing in 2005 tied Alcala to the other four murders.