Three teenagers have been charged with murder and conspiracy to commit grievous bodily harm after a boy, 13, was stabbed to death in Reading.
Oliver Stephens, known as Olly, was pronounced dead at Bugs Bottom fields, Emmer Green, on Sunday.
Two boys, aged 13 and 14, and a girl, aged 13, will appear in Reading Magistrates' Court on Thursday.
Two other boys, also aged 13, have been released on bail, with strict conditions, until 1 February.
The girl has also been charged with perverting the course of justice.
In a statement, Oliver's family said: "An Olly-sized hole has been left in our hearts."
His parents said their son was "an enigma", and having both autism and suspected pathological demand avoidance meant "he became a challenge we never shied away from".
The family described the ordeal as "every parents' worst nightmare".
They also sought to highlight those who helped at the scene, including "a Good Samaritan that tried valiantly to save Oliver", an off-duty doctor who offered help, and the emergency services.
Officers were called just before 16:00 GMT on Sunday following reports of an attack in fields on the boundary of Emmer Green and Caversham Heights.
Parents laying flowers at nearby Highdown School called the killing "utterly senseless" and said their children who attended school with Olly were "devastated".
Det Supt Kevin Brown urged anyone with information to contact police and not to share any images or footage on social media.
"This continues to be a very difficult time for the family of Olly. Our thoughts remain with them," he said.
"The Stephens family appreciate all of the kindness shown to them but they have asked that their privacy is respected at this very difficult time."