Through time there has been many examples of kids killing other kids or others. Here you find some earlier stories.
Jesse Pomeroy was fourteen when he was arrested in 1874 for the sadistic murder of a four-year-old boy. He was quickly dubbed "The Boston Boy Fiend." His rampage had begun three years earlier with the sexual torture of seven other boys. For those crimes Pomeroy was sentenced to reform school, but then he was released early. Not long afterward he mutilated and killed a 10-year-old girl who came into his mother's store.
A month later, he snatched four-year-old Horace Mullen. He took Horace to a swamp outside town and slashed him so savagely with a knife that he nearly decapitated the child. Because of his strange appearance—he had a milky white eye---and his previous behavior, suspicion turned to him. When he was shown the body and asked if he'd done it, he responded with a nonchalant, "I suppose I did." Then the girl was found buried in his mother's cellar and he confessed to that murder, too. He was convicted and sentenced to death, although a public outcry against condemning a child to hang commuted the sentence to four decades of solitary confinement.
Mary Flora Bell wanted to "hurt" someone. She was an angry child, the product of an unsettled home in which chronic abuse was the norm. She had a friend, Nora Bell, and they often did things together. When Mary was eleven, she and Nora lured a boy to the top of an air raid shelter. When he fell and was injured, it was thought to be an accident. Two weeks later, the corpse of four-year-old Martin Brown was found, another assumed accident. Then police discovered notes that indicated that someone was taking responsibility---two people, in fact, who called themselves "Fanny and Faggot." Then Mary showed up at Martin's home so she could "see him in his coffin." Two months passed and another local toddler, three-year-old Brian Howe, turned up missing. When Mary suggested that he might be playing on a certain pile of concrete, searchers looked where she indicated and found his body. He'd been strangled and his legs and stomach had been cut with a razor and scissors. The medical examiner believed it to be the handiwork of a child.
Mary and Norma were brought in; Mary made up a story but Norma described watching Mary kill the boy. They went to trial in 1968 in England, where Mary was convicted of two counts of manslaughter. People called her "evil" and a "bad seed," in part because she seemed so indifferent to the proceedings against her. A court psychiatrist said that she was manipulative and dangerous.
Willie Bosket had committed over two thousand crimes in New York by the time he was fifteen, including stabbing several people. The son of a convicted murderer, he never knew his father but revered him for his "manly" crime. Just before he was sixteen, his crimes became more serious. Killing another boy in a fight, he then embarked upon a series of subway crimes, which ended up in the deaths of two men. He shot them, he later said, just to see what it was like. It didn't affect him. He knew the juvenile laws well enough to realize that he could continue to do what he was doing and yet still get released when he was twenty-one. He had no reason to stop.
Yet it was his spree and his arrogance that brought about a dramatic change in the juvenile justice system, starting there in New York. The "Willie Bosket law," which allowed dangerous juveniles as young as thirteen to be tried in adult courts, was passed and signed in six days. Willie went on to commit more crimes, although none as serious as murder, and ended up with prison terms that ensured that he would spend the rest of his life there.
Cindy Collier was 15 and Shirley Wolf 14 when they started prowling condominiums in California in 1983. They knocked on doors at random to gain admittance. An elderly woman let them in and sat chatting with them as they thought up a plan to steal her car. Shirley grabbed her by the neck while Cindy found a butcher knife and tossed it to her. Shirley stabbed her victim 28 times, even as the old woman begged for her life. They fled the scene, but were soon arrested. Both confessed that the murder was "a Kick" and that they wanted to do another one. They thought it was fun.
In 1998, 14-year-old Joshua Phillips bludgeoned his 8-year-old neighbor, and then hid her body beneath his waterbed. Seven days later his mother noticed something leaking from beneath the bed. Joshua claimed that's he'd accidentally hit Maddie in the eye with a baseball. She screamed and he panicked. He then dragged her to his home where he hit her with a bat and then stabbed her eleven times. His story failed to convince a Florida jury, who convicted him of first-degree murder.