Your link says the perp was 6 feet tall and 225 pounds and a noted football player at his school. He would have had allies, so why didn’t he just sock the other guy in the nose?
My guess is that this Yout has adopted the thug mentality where human life is cheap and his need for everyone to respect him at first glance is essential to his self worth.
Then the fact that the person ‘disrespecting’ him was white was just something that called out for lethal force.