iStock/Thinkstock(HOUSTON) –Authorities are searching for a gunman after a 7-year-old girl was shot dead in a Walmart parking lot in Houston Sunday as the girl sat in her car with her mother and three other children.

The unknown suspect, who was driving a red pickup truck with no plates, pulled up next to the victims’ car at about 7 a.m. and began shooting into their car for an unknown reason, Harris County Sheriff Ed Gonzalez tweeted.

The 7-year-old girl’s mother was shot, too, Gonzalez said. She was wounded in the arm but is expected to survive, officials said.

In addition to the girl and her mother, two teenagers and a younger girl were also in the car, Gonzalez said.

The younger girl suffered glass fragment injuries and the teens weren’t hurt, but they were “shaken” and “devastated,” said Jesse Razo, a major with the sheriff’s office.

The suspect, who was still at large as of Sunday morning, “is considered armed and dangerous,” Razo told reporters.

The motive for the shooting was not immediately clear.

Homicide detectives were scouring the area and checking surveillance video for clues.

“We’re going to use all resources available to bring this killer to justice,” Razo said.

He urged the suspect to surrender.

“Because we will be looking for you, we will locate you, we will find you,” Razo said.

The suspect was wearing a red hoodie and fled in a red truck, Gonzalez said. He was described as being in his 40s and having a beard, Razo said.

The sheriff’s office urged anyone with information to call 911, tweet at @CrimeStopHOU or call 713-222-TIPS.

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