A mass shooting at Cielo Vista Mall on Wednesday was a “random incident” between two groups in the mall food court, El Paso police said in a noon briefing a day after the shooting.

“This is a random incident, encounter, between two groups. I want to emphasize this,” Interim Police Chief Pete Pacillas said. “This is a random incident that occurred between two groups at the mall. The confrontation between the groups took place in the food court area of the Cielo Vista Mall, and that’s where it was isolated to. During the confrontation, a physical altercation took place.”

One person was killed and three wounded by gunfire, Pacillas said. Two of the wounded are in stable condition and one is in critical condition, he said.

Police have not identified the two suspects detained after the shooting, or the people killed or injured. Pacillas said the participants in the shooting were in their late teens to early 20s, and he said the violence was not gang related.

Pacillas provided limited details of the shooting, citing an ongoing investigation. He described those involved as being in two groups that he labeled Group A and Group B.

“During that fight, Group B, one person produced a handgun, and shots were fired. As a result of the shooting, one member in group A was fatally wounded and deceased at the scene. Two persons in Group B were wounded and are listed in stable condition at local area hospitals,” he said.

Pacillas did not say how the third person was wounded, nor did he say what sorts of guns were involved. A police spokesperson later clarified that another member of Group A was shot and seriously wounded.

The interim police chief said at least three people in the area of the shooting were “legally armed” at the time of the shooting. Texas law allows people over age 21 to possess handguns, and generally allows people over 21 to carry guns in public settings. Pacillas said the mall is not among areas where Texas law prohibits carrying weapons.

Pacillas did not say if any of those three people produced a weapon or fired during the altercation.

A source familiar with the investigation, who asked not to be identified because he’s not authorized to speak publicly, has told El Paso Matters that one bystander fired a weapon during the fight.

Police have said an off-duty police officer working security at a mall store detained a suspect within three minutes of the first report of the shooting. At the news briefing Thursday, Pacillas said he was unable to say how the second suspect was detained, but said police would provide the information.

Hundreds of cars parked at the Cielo Vista Mall parking lot have been declared part of a crime scene and not accessible to owners in the aftermath of the shooting. Pacillas said those vehicles would be released to owners Thursday afternoon.