Pacillas said police received calls of a suspect firing off several rounds, killing one person and wounding three others, at approximately 5:05 pm and the officer took a suspect into custody by 5:08 p.m.
Later in the press conference, Pacillas said it is unclear at this time if the suspect fired at the off-duty officer.
The police chief said officers from multiple departments, including the El Paso Police Department, the Texas Department of Public Safety (DPS), U.S. Border Patrol and the local FBI responded to the "dynamic scene" at the mall and "quickly brought it under control."