True crime fans know that history is rife with felonious duos spreading mayhem and violence, such as Bonnie and Clyde, Butch Cassidy and the Sundance Kid, and the Lonely Hearts Killers. But perhaps the scariest and most depraved stories of all time involve siblings. There’s just something about their unshakeable bond, and the impenetrable level of psychological intimacy that can take them to some very dark places.

Here are a few of the most horrifying murderous siblings of all time; their sins made all the more spooky given that their true motives remain cloaked in mystery.

 

1. The Papin Sisters

Papin sistersScandalizing an entire nation and touted as the crime of the century, Christine and Lea Papin were accused in 1933 of gruesomely murdering their employers in what seemed to be a crazed act of raving madness.

The sisters grew up in the kind of French squalor that would be deemed near cartoonish nowadays; their parents separating the girls at a young age and forcing them to become maids in different houses in order to collect their wages. Eventually, the sisters reunited, and began working for the Lancelin household; a typically bourgeouisie family in the city of Le Mans. This is when things began to go downhill.

One night, the Lancelin women arrived late from a shopping spree, and upon learning that the power had gone out, Madame Lancelin flew into a rage. In self-defense, Christine grabbed a pewter jug and hit her mistress over the head, after which Genevieve, the daughter, came running after the elder Papin sister. The scuffle soon turned into a free for all, with Christine supposedly screaming “I’m going to massacre them!”

Both sisters then proceeded to tear the Lancelin women eyes’ out, stab them repeatedly with a knife, and beat their faces to a pulp with a hammer. In a final grisly touch, they brought the women’s skirts’ over their heads, and further gouged out their thighs and private parts, completing the dreadful, sexually violent crime.

Their bizarre case became a cause célèbre of sorts, with lurid undertones of lesbianism and incest, and their motives were never fully clarified. Were the girls caught in the grip of pure insanity, or did they make a conscious effort to take revenge upon their oblivious and casually cruel employers? We will never know.

 

2. Stewart and Cyril Marcus

Stewart and Cyril MarcusAlright, well maybe these two weren’t technically the most sinful of the bunch presented here, as they hurt themselves more than anyone else, but their story is still completely horrifying and ended tragically. The identical twin brothers were renowned gynecologists on staff at New York Hospital-Cornell Medical Center during the 1960s and even shared an apartment. However, the brothers’ bond became overpoweringly close and psychotic, leading to their death in 1975.

 

Cyril, who was divorced, moved in with Stewart after the latter’s girlfriend left him. The two soon developed a strange penchant for sharing everything, from the same living quarters, drugs, to the same women, bouncing girlfriends between the two of them without letting their female companions know which brother they were with.

Their behavior at the hospital became increasingly erratic, seeing them skip their shifts and canceling appointments at their private practice. During a particularly hot week in the summer of 1975, neighbors complained incessantly of a foul odor emanating from the Marcus’ apartment. The 45 year old twins were found dead, a result of a joint suicide brought about by barbiturate overdose. It has been speculated that they fell into a deep depression and eventually experienced a psychotic break from reality as a result of the drugs; their unbearably close relationship probably leading to insanity.

 

3. Raya and Sakina

Raya and SakinaEgypt’s most famous serial killers, these sisters began killing women in Alexandria at the turn of the 20th Century, for a multitude of reasons that remain rather vague, if not properly understood. The prime motives point primarily to poverty, class-based anger and paranoia, and perhaps psychosexual turmoil.

Local police in the town of Labban, Alexandria were plagued for years by increasing reports of missing women, all tied by two defining characteristics: their gender, and apparent wealth – they were reported to be wearing gold jewelry, and carrying large sums of money. They were also almost always last seen with a woman named Sakina, who, despite facing interrogation multiple times skillfully dodged any suspicions of her involvement.

But this soon came to an end on a winter’s day in 1920, when a passerby came across a dismembered body damaged beyond recognition. Within the same timeframe, another man reported finding human remains underneath his floor tiles while trying to fix a water pipe. Finally, law enforcement figured out that Raya and Sakina were renting a home in which they lured wealthy women, drugged, and eventually murdered them, hiding their remains underground. The sisters were the first women to be given the death penalty in the newly formed Egyptian courts of the time, independent from colonial rule.

Their case remains huge in pop-culture, being given both the horror and comedic treatment in films, literature, and plays. But perhaps their legacy is still hugely significant as their crimes revealed the seedy underbelly lurking behind Alexandria’s elite cosmopolitan veneer, pointing to a history that no one enjoys talking about.

 

4. Delfina and María de Jesús González

Similar in some ways to Raya and Sakina, these sisters from Guanajauto, Mexico preyed primarily on younger women during the 1950s and 60s, and remain listed as one of the most productive murder partnerships of all time, according to the Guinness World Book of Records.

The sisters ran what was thought to be one of the biggest prostitution rings of all time, kidnapping young girls and force feeding them heroin or cocaine as they transitioned to a life of prostitution. When any of the girls were deemed too ill, “sexually damaged,” or were not attractive to their customers, they would unceremoniously kill and dismember them. Delfina and María also murdered their richer clientele for money.

Their operation ran for nearly two decades, and the exact number of those who fell under their sway remains a mystery. Upon their arrest, the women expressed no remorse for their crimes, simply stating that everyone perished because “The food went bad.” Both were sentenced to 40 years in prison. Delfina died accidently while serving her time, but it is said that María eventually left prison and managed to quietly disappear amongst the general populace; her exact fate is unknown.

 

5. “Big” and “Little” Harpe

Usually referred to as America’s first serial killers, it is still unclear whether “Big” and “Little” were actually brothers or cousins. In either case, they made for one revolting duo, leaving a trail of chaos in the American Midwest of the late 1700s.

Referred to as their “trail of slaughter,” their crimes began as part of a drunken brawl at a bar. The brothers – or cousins – for reasons known only to them, disemboweled and filled the bodies of their drunken prey with stones, casting them into the river. It is widely believed that the pair would go on to commit nearly 40 such murders, alongside women who referred to themselves as their wives, who may or may not have been their willing accomplices.

They were finally captured and beheaded by the authorities, their heads put on public display in Kentucky as a deterrent to anyone interested in emulating their crimes.

 

Two Against the World

These peculiar stories trace the dangers of filial relationships that have soured. Sometimes this is due to economic pressure, being raised in a broken home, or getting caught up in a sick power struggle amongst themselves, and by extension the world. The loyalty and trust between siblings is a beautiful thing, but it can sometimes lead them to very dark places, as these tales illustrate.