A 16-year-old girl has pleaded guilty to killing seven-year-old Katie Rough.
The girl, who cannot be named for legal reasons, pleaded guilty to manslaughter by diminished responsibility.
Katie was smothered and slashed with a Stanley knife by the teenager on a playing field in Woodthorpe, York, on 9 January. She died later in hospital.
Leeds Crown Court heard the killer suffered with severe mental health problems and was convinced people "weren't human and were robots".
Katie's family were in court to hear the guilty plea.