In October 2015, Bailey Gwynne was attacked during his lunch hour following what was dubbed as a silly argument at Cults Academy in Aberdeen. His killer carried an 8.5cm blade that he bought online.
Bailey died from bleeding due to a single stab wound to the heart.
The youth, who cannot be named for legal reasons, denied the murder. After a five-day trial at the High Court in Aberdeen last March, Lady Stacey convicted the boy of culpable homicide, a lesser charge than murder.
The judge argued that Bailey’s death would have been avoided had the teenager not chosen to carry a knife to school.