DALLAS (AP) — The student who shot four students when he opened fire at a Dallas high school this week was in and out of the building in less than two minutes and is believed to have been targeting a specific student, the school district police chief said Thursday.

The 17-year-old suspect was able to enter Wilmer-Hutchins High School at 1:01 p.m. Tuesday when another student opened a locked side door, Dallas Independent School District police Chief Albert Martinez said at a news conference. The school has metal detectors at its main entrance, he said.

The suspect was taken into custody several hours after the shooting. He remained in jail on Thursday on a charge of aggravated assault mass shooting.

Martinez said that they believe there was “a dispute taking place,” but they do not yet know what led to the shooting.

“We don’t have that information as to the why, the motivation,” Martinez said.

Martinez said they are looking into “how deep” the culpability is of the student who opened the door.

Four male students were shot and were taken to hospitals, according to officials. All of those injured are all expected to make a full recovery, Martinez said.

The shooting drew a large number of police and other law enforcement agents to the roughly 1,000-student campus.

The suspect parked his vehicle at the school just before 1 p.m., Martinez said.

An arrest warrant said that after the suspect was let into the building, he walked down a hallway until he spotted a group of students. The arrest warrant says he then displayed a firearm and began firing “indiscriminately” before approaching a student who was not able to run and walking toward that student and appearing to take a point-blank shot.

The suspect’s bond was set at $600,000. Jail records did not list an attorney for him.

At the same school last April, one student shot another in the leg.

Sheriff vehicles sit parked in a lot at Wilmer-Hutchins High School, where police are responding to reports of a shooting at in Dallas, Tx., Tuesday, April 15, 2025. (AP Photo/Julio Cortez)

Credit: AP

icon to expand image

Credit: AP

Dallas Independent School District Superintendent Stephanie Elizalde, left, and DISD Chief of Police Albert Martinez speaks during a news conference about the Wilmer-Hutchins High School shooting, Thursday, April 17, 2025, in Dallas. (Tom Fox/The Dallas Morning News via AP)

Credit: AP

icon to expand image

Credit: AP

An undercover Texas Highway patrolman arrives to Wilmer-Hutchins High School, where police are responding to reports of a shooting at in Dallas, Tx., Tuesday, April 15, 2025. (AP Photo/Julio Cortez)

Credit: AP

icon to expand image

Credit: AP

A woman carries a child as she and a student of Wilmer-Hutchins High School leave after authorities reported the campus had been secured following reports of a shooting, in Dallas, Tx., Tuesday, April 15, 2025. (AP Photo/Julio Cortez)

Credit: AP

icon to expand image

Credit: AP

Parents are checked in to pick up their children at Wilmer-Hutchins High School, where police are responded to reports of a shooting at in Dallas, Tx., Tuesday, April 15, 2025. (AP Photo/Julio Cortez)

Credit: AP

icon to expand image

Credit: AP

Dallas ISD Superintendent Stephanie Elizalde, right, speaks alongside Dallas ISD assistant police chief Christina Smith during a news conference after a shooting at Wilmer-Hutchins High School, Tuesday, April 15, 2025, in Dallas. (Elías Valverde II/The Dallas Morning News via AP)

Credit: AP

icon to expand image

Credit: AP

Superintendent Stephanie Elizalde, left center, exits the Wilmer-Hutchins High School youth and family center after authorities reported the campus had been secured following reports of a shooting, in Dallas, Tx., Tuesday, April 15, 2025. (AP Photo/Julio Cortez)

Credit: AP

icon to expand image

Credit: AP

Superintendent Stephanie Elizalde, left center, speaks with a highway patrolman outside Wilmer-Hutchins High School after authorities reported the campus had been secured following reports of a shooting, in Dallas, Tx., Tuesday, April 15, 2025. (AP Photo/Julio Cortez)

Credit: AP

icon to expand image

Credit: AP

Parents arrive to pick up their children at Wilmer-Hutchins High School, where police are responded to reports of a shooting at in Dallas, Tx., Tuesday, April 15, 2025. (AP Photo/Julio Cortez)

Credit: AP

icon to expand image

Credit: AP

A woman arrives to a checkpoint outside Wilmer-Hutchins High School, where police are responding to reports of a shooting, in Dallas, Tx., Tuesday, April 15, 2025. (AP Photo/Julio Cortez)

Credit: AP

icon to expand image

Credit: AP

A fire engine blocks a road accessing Wilmer-Hutchins High School, where police are responding to reports of a shooting, in Dallas, Tx., Tuesday, April 15, 2025. (AP Photo/Julio Cortez)

Credit: AP

icon to expand image

Credit: AP

Students sit on stadium bleachers as Wilmer-Hutchins High School, where police are responding to reports of a shooting at in Dallas, Tx., Tuesday, April 15, 2025. (AP Photo/Julio Cortez)

Credit: AP

icon to expand image

Credit: AP

Dallas Independent School District Superintendent Stephanie Elizalde speaks during a news conference about the Wilmer-Hutchins High School shooting, Thursday, April 17, 2025, in Dallas. (Tom Fox/The Dallas Morning News via AP)

Credit: AP

icon to expand image

Credit: AP

Dallas Independent School District Superintendent Stephanie Elizalde speaks during a news conference about the Wilmer-Hutchins High School shooting, Thursday, April 17, 2025, in Dallas. DISD Chief of Police Albert Martinez is seen at right. (Tom Fox/The Dallas Morning News via AP)

Credit: AP

icon to expand image

Credit: AP

Featured

Pinky Cole's Ponce City Market location in Atlanta, Georgia, 'Bar Vegan', during lunch time on April 5, 2024. (Jamie Spaar for the Atlanta Journal Constitution)

Credit: Jamie Spaar