THE girl who killed seven-year-old Katie Rough has been locked up for life because no-one knows how long she will remain a danger to the public.

She clutched a cuddly toy as Mr Justice Soole declared that she will only be freed when the Parole Board decides she is no longer dangerous to others.

Members of Katie’s family were at Leeds Crown Court to see the end of the case that began when the teenager smothered and stabbed their daughter on a path in Woodthorpe on January 9.

The judge said: “The utter tragedy of all this needs no emphasis.”

Defence barrister Nicholas Johnson QC said: “This was a killing of a child by a child in particular circumstances. We submit she was fundamentally driven to this killing by her mental disorder.”

The court heard psychiatrists agree that she has major mental difficulties but cannot agree on what the older girl is suffering from.

In a report to the court, psychiatrist Barry Chipchase said: “We do not yet fully understand (her) reasons for killing (Katie).

“My view is she should be considered a high risk of doing serious harm to others.”

The judge said: “I do not consider that the court is in a position to make any reliable estimate of the period of continuation of the present high risk.

“Accordingly in this exceptional case, I have concluded that it is necessary to impose a sentence of detention for life.”

He ordered that the teenager serve a minimum of five years from January, but warned that she will only be released when the parole board decides she is no longer a danger to others. The teenager, from York, now 16, pleaded guilty to manslaughter on the grounds of diminished responsibility at an earlier hearing. She attended court via a video link.

The judge said she had gone with Katie to the field at the end of the path in the late afternoon of January 9.

“What precisely happened next is known only to you, since you remain unwilling and/or unable to say anything about it beyond your plea of guilt,” he told the teenager, who showed no reaction and throughout the hearing sat looking down at her fingers.

But after the fatal attack, the teenager called the emergency services and remained nearby until the police arrived.

She also handed over the knife she had taken with her to the scene.

None of her family were available at the court to speak to the media.

Mr Johnson, for her legal team, said: “This has been a challenging case for all concerned, today and throughout. Our thoughts remain with Katie’s family.”

Doctors have spent the last three months assessing the teenager’s mental state to see if she was suffering from a mental illness that could be treated if she was detained under the Mental Health Act.

They decided she was not.