At 15 years old Tirrell was walking home from school with other boys ranging from 13-15 years old. A boy he knew that had been excluded from the school they both attended joined them.
Another older boy who took offence that Tirrell had spoken to his girlfriend in his presence, followed them from the bus station making threats, whilst Tirrell was on his way home.
Other children heard about the commotion and came to see what was happening. Tirrell did not want to fight the victim, which was shown on CCTV and after a scuffle he withdrew and went home.
The victim then punched the boy that had previously been with Tirrell earlier full in the face, who than fatally stabbed him with one fatal blow.
Five boys were charged with Joint Enterprise and convicted of murder and manslaughter – Although Tirrell was not present at the time of the incident he received 15 years life sentence, reduced on appeal to 13 years life.