From the NYT:

There were multiple victims in the shooting.

A sunny day at a shopping mall complex in this border city turned into chaos and bloodshed late Saturday morning, after a gunman opened fire inside a Walmart store, killing multiple people, wounding others and sending panicked shoppers into nearby stores.

The office of the El Paso mayor, Dee Margo, said in a statement that the police had confirmed several fatalities. The police declined to elaborate on the number and status of the victims.

Much about the shooting remained unclear as of Saturday afternoon. It was unknown how many had died and had been wounded. Police officials said one gunman was in custody.

The gunfire on Saturday in El Paso began a few minutes before 11 a.m., in a popular commercial district near Cielo Vista Mall with scores of restaurants and stores that are often crowded on the weekends. The Walmart store, located near Hawkins Boulevard and Gateway Boulevard West a short distance from the mall, was packed at the time.

Full article here.