Karmelo Anthony, 17, is currently in custody and charged with murder following the death of 17-year-old Austin Metcalf on the morning of April 2.

The two boys were both at Kuykendall Stadium in Frisco when Anthony allegedly removed a knife from his backpack and stabbed Metcalf, who was pronounced dead by the time he arrived at the hospital, according to police.

PEOPLE obtained a copy of the probable cause affidavit in the case, which notes that Anthony had distanced himself from the victim and other athletes when police arrived on the scene.

The arresting officer ordered Anthony to put his hands up, at which time Anthony allegedly shouted: “I was protecting myself.”

Anthony then complied with the officer’s instructions and requests as he was led off the field for questioning, according to the affidavit.

When the officer referred to Anthony as an “alleged suspect,” he seemingly admitted to the crime in response, allegedly saying “I’m not alleged, I did it,” according to the affidavit.

Anthony then became emotional as the officer led him to his vehicle, and according to the affidavit said: “He put his hands on me. I told him not to.”

He also asked one of the other officers a question.

“While walking to my patrol vehicle Anthony made another spontaneous statement and asked if what happened could be considered self-defense,” the affidavit states.

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Anthony was then booked into the Frisco Jail, where he remains in custody. A judge has set Anthony’s bail at $1,000,000, per an order of commitment obtained by PEOPLE.

The affidavit also details just how quickly things escalated between Metcalf and Anthony.

An eyewitness told police that Metcalf asked Anthony to move out from under the tent that had been set up for members of his high school track team on the field that day.

Anthony then reached into his bag according to the eyewitness, and told Metcalf: “Touch me and see what happens.”

The eyewitness said Metcalf touched Anthony, at which time Anthony allegedly told him to punch him and see what happens, according to the affidavit.

Metcalf then went to physically move Anthony, which is when Anthony allegedly pulled a knife out of his bag, stabbed Metcalf in the chest, and fled from the tent, according to the eyewitness,

The entire altercation lasted less than 30 seconds, according to the affidavit, and multiple eyewitnesses backed up this version of events.

Police then arrived on the scene to find multiple coaches from the Frisco Independent School District surrounding Metcalf as trainers performed CPR and other life-saving measures

Officers also met with the victim’s brother Hunter, according to the affidavit. He could not speak because he was so overcome with emotion.