Mohammed Umar Khan: Knife-obsessed teen who murdered Harvey Willgoose sentenced

A knife-obsessed teenager who stabbed another pupil to death in his school can today be named as Mohammed Umar Khan.The 15-year-old was found guilty of murdering Harvey Willgoose, also 15, during their lunch break at All Saints Catholic High School in Sheffield on February 3.Khan inflicted a fatal stab to Harvey's heart during a nine-second confrontation in front of other pupils in the school courtyard at 12.15pm. The two boys had recently fallen out on social media.He was convicted of murder in August following a trial at Sheffield Crown Court, when he failed to persuade a jury that his actions were manslaughter because bullying had led him to lose his control.