A teenager is in custody, facing felony charges in connection with Tuesday’s shooting at Wilmer-Hutchins High School that hospitalized at least five students, officials say.

An arrest warrant affidavit obtained by NBC 5 said Dallas ISD police reviewed school surveillance footage showing an unidentified student letting Tracey Haynes Jr into the building through an unsecured door at about 1:03 p.m.

According to police, Haynes walked down a hallway toward several male students and then began indiscriminately shooting, striking five people. Police said Haynes then walked toward another student and appeared to “take a point-blank shot.”

“Five injured students that were shot were transported to local hospitals,” Dallas ISD police said in the affidavit.

Dallas Fire-Rescue told NBC 5 on Wednesday morning that only four students had been shot and the fifth was transported for anxiety. The victims ranged in age from 15 to 18, and their injuries were classified as serious to non-life-threatening. On Wednesday, DFR said, two victims remained hospitalized and were expected to recover.

Haynes surrendered to police outside the Dallas County Jail on Tuesday evening. He is charged with first-degree aggravated assault mass shooting, the affidavit said. His bond has been set at $600,000, and it’s unclear if he’s obtained an attorney.

Police said that because more than four people were injured in the shooting, the aggravated assault charge was elevated to a mass shooting.

Police have not released the victim’s identities or a motive for the shooting.