A Texas jury sentenced 19-year-old Karmelo Anthony on Tuesday evening to 35 years in prison for the murder of Austin Metcalf, 17, last April at a high school track meet in which they were competing.

Witnesses testified during the week-long trial north of Dallas that the two teens clashed after Anthony took shelter under Metcalf’s team tent. Anthony pulled a knife and later confessed to law enforcement, although he and his attorney insisted it was self-defense.