r Metcalf, a student at Frisco Memorial High School, asked Anthony, a student at Frisco Centennial High School, to leave his team's tent, jurors heard at trial.

Things escalated with Metcalf shoving Anthony, who responded by taking a folding knife out of his backpack and stabbing Metcalf once in the chest, according to trial testimony.

Anthony claimed the knifing was self-defense.