Crossing the playground at lunchtime, 15-year-old Harvey Willgoose had no idea his friend turned enemy Umar Khan had come to school with a hunting knife stuffed beneath his coat.

Crossing the playground at lunchtime, 15-year-old Harvey Willgoose had no idea his friend turned enemy Umar Khan had come to school with a hunting knife stuffed beneath his coat.

Pupil Harvey Willgoose, 15, was brutally stabbed to death by fellow student Mohammed Umar Kahn at their Sheffield High School following a fallout between groups