Dallas ISD police officer shot, seriously injured, in parking lot of Northwest Dallas Sam's Club

A Dallas ISD police officer was shot and injured in Northwest Dallas late Thursday morning.

CBS News Texas's JD Miles reports that the officer suffered serious injuries and was taken to Parkland Hospital. The officer is expected to survive.

Early Thursday afternoon, Dallas ISD confirmed that one of its police officers was wounded "while assisting a citizen at an off-campus location," but provided no additional details. 

Video from CBS News Texas Chopper shows dozens of Dallas police officers are in the area of the Sam's Club on 635 and Midway.

Sammy Garcia, who was inside the Sam's Club with his daughter and granddaughter, told CBS News Texas's Marissa Armas that police kept shoppers inside the store for about 40 minutes. 

"They were very nervous, very scared of course. Never been in a situation like this," Garcia said.

A large area of the parking lot is closed off with crime scene tape, and officers can be seen looking for something in a nearby neighborhood.

This is a developing story and will be updated.