Evil Children Who Took Their Sibling Rivalry Too Far

#1 Constance Kent

This caused a huge stir given the girl's well-to-do background, and the case against her soon collapsed. However, five years later Constance made a chilling confession to a clergyman she had taken her brother in the middle of the night and killed him using one of their father's razor blades. Though she never gave a motive for the murder, many believe it was jealousy due to her father showing more affection to the children of his second marriage.

#2 Erika deNardo

Things came to a terrible head on the night of February 21st, 2001 when Erika's mother, Susanna Cassini, and her brother were found murdered at the family home. They had each been stabbed over 100 times. Though she told investigators that the killings were the result of a botched robbery, Erika and her boyfriend were found guilty after being secretly recorded talking about themselves carrying it out. Erika was sentenced to 16 years in prison and her boyfriend was sentenced to 14. Erika's father, who was out at a football match at the time of the murders, forgave his daughter for the horrific crime.

#3 Elizaveta Dubrovina

Though not technically a child given that she was actually 19 at the time, the case of Elizaveta and her 17-year-old sister Stefania, is worthy of inclusion due to the shocking brutality of the crime, which is particularly chilling given that is was apparently committed by a sister. Model Stefania was found at an apartment in St Petersburg, Russia, hacked to death with her eyes gouged out and ears cut off on February 23rd 2016.

According to reports at the time of the murder, Elizaveta was envious of her younger sister, who enjoyed a glamorous lifestyle as a nude model. The pair were allegedly partying with a male friend, who had gone to get more alcohol when the shocking attack occurred. The siblings didn't have the best start in life, after being removed from their parents in their earlier days, and it has also been reported that Elizaveta had been treated at a psychiatric hospital. The girls' aunt said of the crime "My blood turns to ice. These poor children are not guilty in their gruesome childhood and in all their unhappy life which unfortunately ended for Stefania."

#4 Cristian Fernandez

On March 14th 2011, 12-year-old Cristian Fernandez beat his 2-year-old half brother to death while being left to watch him alone. Though the details of exactly what occurred that day remain unclear, it is thought that after their mother left their Florida home Cristian began being abusive to his sibling, eventually shoving him hard into a bookcase. He was initially charged with first-degree murder, though this was changed to manslaughter in 2013 after a plea deal with prosecutors, meaning he will stay in juvenile until he's 19.

#5 Girl A

Though the majority of teenage girls argue with their sisters, one moment of blind anger caused a tragedy for the next family. Back in 2007, a 14-year-old girl (who couldn't be named for legal reasons) pleaded guilty to manslaughter after stabbing her 16-year-old sister during a squabble at their home in West Yorkshire, UK. The older sister shouted that her sibling's boyfriend "wouldn't amount to much", before the younger girl screamed "you're going to get it" and plunged a carving knife into her back.

#6 William Gorzynski

On October 26th, 2009, William Gorzynski plunged a knife into his 14-year-old brother Matthew's chest in a moment of rage. The reason? The pair had gotten into a heated argument over computer speakers. William, who was watching TV at the time, complained that his brother's music from the computer was too loud, and after yelling at each other the dispute became physical. William then went to the kitchen and grabbed a knife, stabbing Matthew once in the chest.

#7 Keith Randulich

Most big brothers would never dream of hurting their little sisters, let alone murdering them in such a brutal manner, but sadly this wasn't the case for 18-year-old Keith Randulich. On May 22, 2009, after arguing with his mother when she refused to buy him a gun, he took his 4-year-old sister Sabrina, down to the family's basement and stabbed her in the neck until he "felt bone". Keith later told police that the girl had pleaded with him during the attack "Stop why are you killing me?".

#8 Demetrius Key

13-year-old Demetrius Key was arrested for first-degree murder in October of 2007, after beating his younger brother to death. Their mother had left the older boy in charge of his siblings while she visited a cousin, despite the fact that he had been violent towards his younger brother before. Demetrius told police he had become angry with 8-year-old Leavers after he had eaten a dessert that he wasn't supposed to, and was worried that his mother would blame it on him.

#9 Jason Nawara

14-year-old Jason Nawara was described as a polite, mature and responsible boy, so it came as a huge shock to the local community when he murdered his 10-year-old step-sister Tammi Dale Peck, on July 5th 1993. According to a friend of the teen, he had spoken of killing Tammi before that summer day when he shot her in the back of the head while their parents were out.

#10 Helen Patricia Moore

In March of 1980, 18-year-old Helen Patricia Moore's 7-year-old brother Peter, was found dead at the bottom of the stairs of the family's Sydney home. Her mother called the police, and as a result a shocking story of a very disturbed young woman was finally revealed. Not only did Helen confess to murdering her little brother, she also admitted to killing two other children and attempting to kill two more.