A 7-year-old girl was shot to death and her mother wounded early Sunday by a gunman who opened fire on the family as they drove out of a Walmart parking lot in eastern Harris County.

The unknown shooter fled and was still at large by early evening, according to Harris County Sheriff Ed Gonzalez.

LaPorsha Washington and her four children – ages 6 to 15 – were leaving the lot in the 15400 block of Wallisville when a man in a red pickup pulled up before 7 a.m. and opened fire into the family’s car.

Afterward, the 30-year-old mother – who’d been shot in the arm – drove away with her children and fled along Beltway 8, making a u-turn before she pulled over to call 911 when she realized 7-year-old Jazmine Barnes wasn’t breathing.

Two teens in the car were unharmed, but the 6-year-old was wounded and the 7-year-old died before paramedics could get her to a hospital.

“Please keep this family in your prayers,” Gonzalez tweeted Sunday evening. “A total of 5 occupants in the car witnessed this innocent child, their loved one, shot and killed before their eyes. So senseless. It’s never easy, and extra hard during the holiday season.”

It’s not clear why the shooter opened fire, and at first the only description investigators could offer was that he wore a red hoodie. Later, authorities fleshed out the description, adding that the shooter is believed to be a white, bearded man in his 40s.

“We’re going to use all resources available to bring this killer to justice,” Major Jesse Razo told reporters at the scene. “And I urge you, whoever did this, you know who you are. Please turn yourself in now – because we will be looking for you, we will locate you, we will find you.”

The suspect should be considered “armed and dangerous,” Razo said. Anyone with information relating to the case is asked to call 911 or Crime Stoppers at (713) 222-TIPS.