The gunman is being held at the Tarrant County Juvenile Detention Center on a capital murder charge, police said.

A student was taken into custody Monday after a shooting outside Lamar High School killed a peer and injured another, Arlington police said.

Police responded to the shooting, which happened on campus outside a school building, at about 6:55 a.m.School typically starts at 7:35 a.m., and not all students were on campus at the time of the gunfire, according to police.

According to police, two shots were fired. One boy was struck and taken to the hospital in critical condition, where he later died, Arlington police Chief Al Jones said at a news conference Monday. His identity has not been publicly released.

Another student, a girl, was grazed by a bullet, Jones said. She was taken to the hospital with a non-life-threatening injury, Jones said.

According to Jones, the gunman left the school’s campus immediately after firing the weapon. Officers identified and detained him based on witness descriptions. Jones did not say where they found him.

The alleged shooter’s identity was not released because he is a juvenile, but Jones confirmed he is being held at the Tarrant County Juvenile Detention Center on a capital murder charge. Jones said additional charges are possible pending the investigation’s outcome.“We need our community’s help to ensure that guns do not end up on school campuses,” Jones said. “We need gun owners to step up … to ensure that they are properly securing their firearms so kids don’t have access to them.”

Lamar High School will remain closed until Wednesday, Arlington ISD Superintendent Marcelo Cavazos said during the news conference, adding that counselors will be available for any student or staff member who needs help.

“Schools deserve to be a safe place for students to learn and to grow every day,” Cavazos said. “Today, we’re heartbroken.”

‘Never thought this would happen to us’

The school was placed on lockdown and it was lifted after police completed a search of the building, according to a tweet from the department about 10:40 a.m.

Stephanie Escamilla, a freshman at Lamar High School, said when she got off the bus Monday morning, she saw a person lying on the ground near the east entrance of the school.

The person was being covered by her principal and a police officer, Escamilla said, but she thought maybe a student passed out. As students were directed into classrooms, Escamilla said there were whispers someone had been shot.

“That’s when it started to feel real,” she said.

Escamilla said students were held in the classrooms for more than two hours before they were ushered onto school buses and taken to the Arlington ISD Athletics Center. In talking to other students on the ride over, Escamilla said the general consensus was they “never thought this would happen to us.”