A Dallas ISD police officer was shot while trying to help someone near the Walmart and Sam’s Club stores in Northwest Dallas on Thursday morning.The officer-involved shooting happened around 11 a.m. outside the shopping center off the LBJ Freeway near Midway Road.Images from SKY 4 showed dozens of police vehicles from multiple agencies in the store parking lot and in the alleyways near the scene. Crime scene tape surrounded a police vehicle and blood stains.Dallas ISD Police Chief Albert Martinez confirmed the injured officer is one of his officers – 39-year-old Officer Justin Jones, who is assigned to White High School and has been with the department for 16 years.Officer Jones was taken to Parkland Hospital with a critical gunshot wound to the leg. He is currently in surgery, the chief said.A possible suspect was taken into custody.Dallas Police Chief Daniel Comeaux said the shooting happened after Officer Jones was flagged down and intercepted someone who was in crisis on the LBJ Freeway. He's in our prayers.