DALLAS — 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.

A classmate unlocked a side door, enabling the alleged shooter’s entry into the building. He then walked down a hallway toward a group of students, opening fire on them and then appearing to take a point-blank shot at one, according to an arrest warrant released Wednesday.

Dallas Independent School District Police Chief Albert Martinez gave an update on his team's investigation into the shooting on Thursday morning. 

What You Need To Know

  • The student accused of injuring four in a shooting at a Dallas high school was let into the building through a locked side door, which another student opened for him

  • The 17-year-old suspect was taken into custody several hours after the shooting

  • School is canceled for the remainder of the week, and students will return to classes sometime next week

  • The suspect was being held in Dallas County jail Wednesday on a charge of aggravated assault mass shooting

The 17-year-old suspect was being held in Dallas County jail on Wednesday on a charge of aggravated assault mass shooting. He was taken into custody several hours after the shooting, which happened just after 1 p.m. on Tuesday at Wilmer-Hutchins High School.

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.

Four male students were injured in the shooting and taken to hospitals, according to authorities. By Wednesday, two had been discharged and two remained hospitalized for observation but were expected to recover, the Dallas Fire-Recue Department said.

Three of those injured were between the ages of 15 to 18 and were shot, according to Dallas Fire-Rescue. A fourth person whose age was unknown had an injury that Dallas Fire-Rescue said could only be identified as a “musculoskeletal injury” to the lower body.

Dallas Fire-Rescue said Wednesday that a fifth person — a 14-year-old female — was later taken to the hospital for anxiety-related symptoms. She had not been shot.

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

School surveillance camera footage showed that an unidentified student let the suspect in through an unsecured door prior to the shooting, according to the arrest warrant. The arrest warrant said that after spotting the group of students in the hallway, he 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.

Martinez said all the doors, including the one the shooter entered through, were locked at the time of the incident. Another student let the suspect into the building at 1:01 p.m., and the shooter opened fire at 1:02 p.m. and then quickly fled the scene.

The student who let the shooter in is currently facing disciplinary actions for violating the school’s code of conduct, and Martinez did not rule out criminal charges in the future. 

Martinez also said he was aware of a video circulating social media that appeared to be from the school’s surveillance system. He said he could not confirm the validity of the content and his team was investigating where the video came from.

Christina Smith, assistant police chief for the Dallas Independent School District, said during a Tuesday news conference that she did not have any information on what led to the shooting.

Smith said the gun didn’t come into the school during “regular intake time.” She said “it was not a failure of our staff, of our protocols, or of the machinery that we have.” But she said she could not elaborate on that.

Stephanie Elizalde, the school district's superintendent, said at the Tuesday news conference that there would be no school at the high school for the rest of the week. But she added that counselors would be available to students. Martinez said on Thursday students will likely return to campus on Wednesday. 

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.

Martinez said he understood the frustration among parents and students with these two incidents happening a little over a year apart, but said his department is doing all the things they are expected to do to keep the students safe.