A teenage girl has been given a life sentence for manslaughter for killing seven-year-old Katie Rough in a park in York.
The judge ordered the 16-year-old, who cannot be named for legal reasons, to be detained for a minimum of five years in what he described as a "truly exceptional case".
Katie died after she was smothered by the teen and then slashed with a Stanley knife in a park in York on 9 January.
The teenager – who was 15 at the time of the attack – admitted manslaughter due to diminished responsibility at a previous hearing, and appeared by video link at Leeds Crown Court for sentencing as Katie's family looked on.
She clutched a soft toy throughout the hearing, and sat with her head down.
Mr Justice Soole told her: "The gravity of the offence of killing a small child speaks for itself. The level of danger to the public is high.
"In the circumstances of your continuing silence, the critical question is whether there is any reliable estimate as to how long that danger will continue."
Katie's family said in a statement: "Today is the end of a process and that is a relief, but it's not the end of our story.
"Our story is about a loving home and family that was torn apart on the day we lost our daughter.
"Our story goes on into the future, where our home feels very empty, but we will keep going for the sake of our other children and our grandson.
"Our hopes for the future are for a loving and safe home for our family, and we hope we will now find the privacy for that to happen."
Katie was found on a playing field with two severe cuts to her neck and chest, but the prosecutor said a post-mortem showed neither caused her death and that the little girl was smothered before the cuts were made.
Police recovered items from the scene and from the teenager's home, including drawings of stick men depicting killing and death.
Books, violent comics and a Simba toy that had its ears cut off and stuffed into its stomach were found in the teenager's bedroom.
Prosecutors said at earlier hearings that the teenager was given medication for anxiety and depression, and had suffered from delusions during 2016.
They said the girl had talked of being convinced that people "weren't human and were robots".
The judge was told she may have been trying to prove Katie was not a robot as she had "irrational beliefs".
"This investigation has been one of the most tragic and challenging I have ever dealt with in my career as a police officer," said DCI Andrea Kell, from North Yorkshire Police.
"There are no positive results from cases such as these. Regardless of the conviction and the sentence, nothing will ever replace the loss of Katie."