India, April 5 -- Karmelo Anthony, 17, fatally stabbed Austin Metcalf at a high school track meet at the David Kuykendall Stadium in Frisco, Texas on Wednesday. The teenager was left to die in his twin brother's arms as police officers arrested the suspect. Now, Anthony's alleged Instagram posts have surfaced, with one photo showing him holding a gun.

After an argument on the field, Anthony stabbed Metcalf, 16, in the chest. The altercation began during the track meet at the Frisco Memorial High School. Hours after the suspect was arrested, his alleged Instagram posts were shared on social media.

In one photo, the 17-year-old could be seen holding a cigarette lighter in one hand, while flashing his middle finger. In another post, Anthon...