A Dutch teenager was found guilty today of fatally stabbing a 15-year-old girl and trying to murder her father over a dispute that first heated up on Facebook, Dutch News reports. Jinhau K, 15, will serve a year in juvenile detention and three more in a psychiatric institution for murdering Joyce 'Winsie' Hau in her home in Arnhem earlier this year. The court found K suffered from "a serious behavioral disorder with psychopathic traits."
According to testimony, two other teens—Polly W and her boyfriend—pressured K to commit the murder after Polly and Joyce, once best friends, fell out over comments Joyce posted about Polly on Facebook. Joyce's father, who was stabbed by K, said he wants officials to raise the minimum sentence for juveniles who commit such extraordinary crimes. After all, he argued, he lost a daughter and her killer lost only a year of his life, the BBC reports. The case against Polly and her boyfriend is pending.