DALLAS — Investigators don’t believe that the 14-year-old girl who shot and wounded a fellow student before turning the gun on herself at a West Texas high school knew the victim, the school district’s superintendent said Friday.

Officials are still looking into possible motives for Thursday’s shooting at Alpine High School, said Alpine Independent School District Superintendent Becky Watley. She said bullying hasn’t been discussed during her conversations with investigators and noted the investigation was ongoing.

Gunshots rang out around 9 a.m. at the school in Alpine, a town about 220 miles southeast of El Paso. Authorities said the 14-year-old died of an apparent self-inflicted gunshot wound in a school bathroom near where the victim was shot, and the victim was taken to a local hospital with injuries that weren’t considered life threatening. Their names haven’t been released.

The local sheriff and police chief didn’t return messages Friday seeking details about the investigation.

Watley said staff and students at the district’s three schools responded fast and exactly as they’d been trained for a shooting incident by locking down classrooms after the shooting was reported. She confirmed that the 14-year-old had moved to the area about six months ago, but she declined to discuss other details.

“It’s an ongoing investigation and we are working closely with law enforcement,” Watley said.

Cade Blevins, a student at the high school who said he was friends with the victim, told television station KOSA that the victim didn’t know the shooter. Blevins said he visited her in the hospital, and she told him she went to the restroom, saw the shooter and tried to flee when she was shot.

Such shootings are rarely carried out by females, according to Jack Levin, co-director of the Brudnick Center on Violence and Conflict at Northeastern University. Levin noted that more than 95 percent of fatal school shootings are committed by males.

“And if you look only at the shooters who are students at the school at the time, almost all of them are boys,” said Levin, who has written several books about mass shootings and school violence. “Boys who open fire are much more likely to do so indiscriminately.”

Levin, who isn’t involved in the Alpine investigation, said there are common motivators in school shootings, such as depression or lack of conventional methods of finding support. He also noted that bullying has been present in more than 80 percent of the school shootings he has studied.