The 15-year-old boy left his home in Alingsås and disappeared one day in early October last year.
A few days later, the now 17-year-old boy, who knew the 15-year-old, was arrested. He was then suspected of kidnapping.
At the same time, a large search effort was underway, involving, among other things, dog patrols, divers, and a helicopter.
Six days after the disappearance, the 15-year-old's body was found in the Säve River, with injuries from over 100 stab wounds. On the same day, the 17-year-old was arrested as a suspect for murder.
In June, the 17-year-old was sentenced by the Alingsås District Court to four years of closed youth care for murder, exactly as the prosecutor had requested.
According to the verdict, the two boys had agreed to meet at the location where the 15-year-old was later found dead. The 17-year-old admits that they met there. But he denies the murder, and refers to self-defense.