Serial killers are hunted by the finest detectives and law enforcement agencies in the world, and it's only a matter of time until a tiny error or oversight leads to the capture. But those errors – seen in hindsight or not – are sometimes pretty damn stupid.
Dennis "the BTK killer" Rader
Between the years of 1974 and 1991, Dennis Rader murdered 10 people in Sedgwick County, Kansas. He was known as the BTK killer for his murder M.O.: bind, torture, kill. And he was caught due to one of the dumbest mistakes in crime history.
Like some other entries on this list, Rader thought he was smarter than everyone else and enjoyed sending taunting letters to police and newspapers. But he wasn't particularly tech literate, so when he wanted to send computer files, he was wondering how safe it would be. Instead of bothering to learn how computers work, he asked the police themselves whether or not they would be able to trace him if he sent a floppy disc.
The police answered his question in a newspaper ad, reassuring him it would be perfectly safe and to go ahead.
And Rader believed it. On February 16, 2005, he sent a package containing a purple 1.44-Megabyte Memorex floppy disk to KSAS-TV in Wichita, also helpfully including some trinkets to prove he was the real deal.
In addition to the files he had intended to send, police quickly found that the floppy disk also contained a Word document Rader believed was gone forever from being "deleted."
Deleting files in normal operating systems only removes the link to the data – the data itself isn't deleted until and if the space is overwritten by chance or intentional scrubbing by specialist programs.
The undeleted file's metadata contained Rader's legal name and place of work, and police quickly wrapped the case up.
Albert "the Gray Man" Fish
It's not known for certain how many people Albert Fish murdered throughout the early 20th century, but it has been estimated to be over 100.
From 1919 to 1930, Fish chose children, African Americans, and the mentally disabled as his victims. Fish would torture and mutilate young children with his "implements of Hell": a meat cleaver, a butcher knife, and a small handsaw. One of those victims were 10-year-old Grace Budd, whose parents he had talked into sending her with him to a fictional birthday party, sometime in the summer of 1928. She was never seen again.
In November of 1934, Fish wrote an anonymous letter to Grace's mother where he bragged about the girl's murder and cannibalization to increase her misery. "How sweet and tender her little ass was roasted in the oven. It took me 9 days to eat her entire body," Fish described in the horrific letter.
He then mailed it in a New York Private Chauffeur's Benevolent Association envelope police were able to trace directly back to his apartment after asking the association about it.
Jeffrey "the Milwaukee Cannibal" Dahmer
Jeffrey Dahmer raped and murdered 17 men and boys between 1978 and 1991, but that number would have been much higher if he hadn't had two monumental lapses of judgement on July 22, 1991.
On that day, Dahmer had 32-year-old Tracy Edwards come to his apartment on the pretext of taking nude photographs. When Edwards entered, he immediately became suspicious due to a foul odor and several boxes of hydrochloric acid on the floor, which Dahmer excused as being for cleaning bricks.
After getting the new victim into handcuffs as per his M.O., Dahmer pressed a knife against Edwards' chest and talked about his plans for the murder. But Edwards managed to keep a cool head, and kept Dahmer from attacking him by talking in a calm tone and pretending to still be friends. This confused Dahmer, who would occasionally look away at the TV and drift off into satanic chants.
Edwards eventually worked up the balls to ask to be released from the handcuffs to go to the bathroom. Dahmer, astonishingly, agreed to this.
Edwards punched him in the face and ran away.
He then returned to the apartment with two police officers, who found Dahmer still there, as well as his drawer full of Polaroid pictures of human bodies in various stages of dismemberment.
Andrei "the Butcher of Rostov" Chikatilo
Andrei Chikatilo, also called the Rostov Ripper, tortured and murdered at least 52 women and children in the Russian SFSR and the Ukrainian SSR between 1978 and 1990.
Chikatilo was first arrested in 1984 while wandering around in public and committing "frotteurism" (rubbing your genitals against people). A search of his belongings revealed a knife with an eight-inch blade, several lengths of rope, and a jar of Vaseline.
The soviet authorities were already on the lookout for a serial killer, and Chikatilo's killing streak would have ended right here – if it hadn't been for an error that mislabeled the serial killer's blood type. This discounted him as a suspect, and he went back to his gruesome business.
On 6 November 1990, a police officer observed Chikatilo washing his hands and face in the Donleskhoz station, where he was wearing formal attire not usually donned by locals. Chikatilo had just murdered a 22-year-old woman, and failed to clean all the blood off his face. He also had grass and dirt on his elbows.
The officer had no formal reason to arrest him on the spot, but his suspicious person report led to Chikatilo's second arrest, where it was finally established that he was indeed the serial murder despite the blood type error.
If you enjoy murdering masses of people while running around and rubbing your dick against random people in the street, Russia is a travel destination to consider. Just remember basic rules of fitting in like wearing normal clothes and not walking around in public with blood all over you.
Israel Keyes had three confirmed murders, but the actual number is probably eight or more as he admitted to various murders in the states he had lived in – four in Washington, one in New York, and so on. Keyes also enjoyed recreational rape, arson, burglary, and bank robbery.
On February 1, 2012, Keyes kidnapped 18-year-old Samantha Koenig and raped her, then killing her the next day. Having her debit card, he claimed she was still alive and demanded a $30,000 ransom to be transferred to it. Apparently unaware that ATMs are always equipped with cameras, and that banks keep records of transactions, he casually used her debit card as he traveled throughout the southwestern United States. He was of course easily tracked down.
He committed suicide while awaiting trail, probably from shame for his stupidity. It's important to note how in-congruent his fail was with his usual criminal know-how. He planned murders long ahead of time and took extraordinary action to avoid detection. He avoided giving police a victim profile. He usually killed far from home, and never in the same area twice. On his murder trips, he kept his mobile phone turned off and paid for items with cash.
The Charles Manson Family
While Manson is not technically a traditional serial killer, and there is debate about whether or not he personally ever attempted to murder someone, his white liberal / black supremacist cult followers murdered nine people in 1969 at the peak of the "counter culture."
Manson believed that there was an impending apocalyptic race war ("Helter Skelter") in which whites would be annihilated, and encouraged his followers to kickstart the events by committing murders and making the attacks seem racially motivated.
But with so many people involved, it was of course only a matter of time before one of them spilled the beans. Susan Atkins, in jail on auto theft charges, bragged to fellow inmates about being connected to one of the murders and it all unraveled from there.
Ted "caught before the full extent of his crimes were discovered and is more known by his legal name" Bundy
Ted Bundy is often described as "handsome" and "charismatic," and he was able to use his charm throughout the mid-70s to lure at least 30 unsuspecting women before raping and murdering them. And Ted Bundy is apparently so charming that women in the 21st century are still falling for him.
Bundy might have been charming with the ladies, but he took a different tack with the police. In 1975, upon spotting a police officer in a Salt Lake City, Utah suburb while cruising with his car, he took off at high speed. The ensuing police chase ended in his capture, as they tend to do. When searching his car, the police found his full kit – a ski mask, a second mask fashioned from pantyhose, a crowbar, handcuffs, trash bags, a coil of rope, an ice pick, and other suspicious items Bundy used for kidnapping and murder. This initiated a chain of events that would lead to his conviction.
Richard "the Iceman" Kuklinski
To the people who knew him, Richard Kuklinski was just a quintessential middle-class New Jersey father. When arrested on December 17, 1986, it would turn out he was also an extremely prolific professional hitman.
Authorities, once suspicious they had a serial killer on their hands, had started called him "the Iceman" because he often kept the bodies of his victims in an industrial freezer for a period of time to sabotage investigators' determinations of time of death.
After dozens of murders (the exact number is unknown), police were able to connect some dots when he started getting careless and being the last seen contact of many missing people. While suspecting Kuklinski of around five murders, they didn't have anything to pin him on.
So they wired up an undercover ATF agent and had him pose as a street slang slinging criminal – whose fictional background happened to include being a fellow hitman. Instead of figuring out the fraud, it wasn't long before Kuklinski started boasting about the creative ways he had dispatched his victims, and it was of course all carefully recorded.
In the end it was Kuklinski's gullibility and bragging that put him behind bars.
Ted "the Unabomber" Kaczynski
Ted Kaczynski was a math genius who was awarded a scholarship to attend Harvard at the age of 16. He also killed three people with homemade explosive devices sent to universities, businesses, homes and public areas across the United States.
Kaczynski's bombings began in 1978 and ended in 1995, shortly after he mailed large media outlets a manifesto railing against the industrial revolution and the effects of technology on our society. The manifesto contained many peculiarities and talked about the same things he had talked about to his family and even in pre-bombing letters to newspapers.
It didn't take long for Kaczynski's family to realize what was up and rat him out to the FBI. Likely he would have been caught even without this help – someone working in media would have had an a-ha moment eventually.
A high IQ doesn't necessarily gift you basic op sec skills.
David "Son of Sam" Berkowitz
David Berkowitz killed eight people in New York City between 1976 and 1977, and it was done, according to his initial claim, on the orders of a demon inhabiting the dog belonging to his neighbor "Sam."
The hunt for the killer quickly became one of the biggest manhunts in history, no doubt helped by Berkowitz' obsession with taunting the police in letters.
In the end, it was a parking ticket, and pure stupidity, that put Berkowitz behind bars. On July 31, 1977, Berkowitz had murdered a young couple before returning to his car and finding that it had been ticketed. He fired several gun shots after a woman who was looking at him because she had seen the ticket being issued moments before. He missed all of his shots, and then decided to drive home.
It turns out that the woman wouldn't report the attempted murder for four days, giving Berkowitz more than enough time to destroy any evidence or escape to another country. Which he didn't do, because he didn't possess the basic insight to realize police would soon look up that parking ticket and come knocking on his door.
When police arrived they found maps of the crime scenes, a threatening Son of Sam style letter addressed to the police, and three diaries full of meticulous notes about, among other things, hundreds of arsons he claimed to have set throughout New York City.