The suspect in the deadly stabbing — Karmelo Anthony, a student at Frisco Centennial High School — has been charged with first-degree murder, police said.

One officer who responded to the scene said Anthony told him unprompted, without being asked any questions about the incident, “I was protecting myself,” according to the arrest report.

When the officer advised another responding officer that he had “the alleged suspect,” Anthony reportedly responded, “I’m not alleged, I did it,” according to the arrest report.

As he was walking toward the squad car, Anthony “was emotional,” reportedly saying unprompted, “He put his hands on me, I told him not to,” according to the arrest report. Once in the back seat, he also reportedly asked if Metcalf was “going to be OK,” according to the report.

Anthony “made another spontaneous statement” and reportedly asked an officer if what happened “could be considered self-defense,” according to the arrest report. Another officer reported that the suspect was “crying hysterically” while being walked away from the stadium, the report said.

Anthony is being held in the Collin County jail on $1 million bond, court records show. When reached for comment on Friday, his attorney told ABC News he had been on the case for only a few hours and needed to catch up.

Anthony’s father told ABC News on Thursday that they do not have a statement to make at this time.

The stabbing occurred under the Memorial High School tent in the stadium bleachers at approximately 10 a.m. on Wednesday, according to the arrest report.

Responding officers say they spoke to multiple witnesses, including one who reported that the altercation began after Metcalf told Anthony to move out from under their team’s tent, according to the arrest report.

The witness reported that Anthony allegedly reached inside his bag and said, “Touch me and see what happens,” according to the arrest report.

According to a witness, Metcalf grabbed Anthony to move him, and Anthony allegedly pulled out what the witness described as a black knife and “stabbed Austin once in the chest and then ran away,” the arrest report stated.

An officer recovered a bloody knife in the bleachers, according to the report.