This is the chilling moment a teenager was caught pushing Harvey Willgoose in a school corridor a few hours before stabbing him to death with a hunting knife.

The 15-year-old, who cannot be named for legal reasons, was today found guilty of murdering Harvey Willgoose, also 15, during their lunch break at All Saints Catholic High School in Sheffield on February 3.

The boy 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.

Now, following the verdict, police have released have released haunting footage of the defendant in the moments before the attack.

It was captured shortly after both boys had arrived at school and saw each other for the first time since the defendant warned Harvey in a private message on Snapchat that morning: ‘If u wan beef we can hav it.’