A 29-year-old mail carrier was among the seven people killed when a gunman opened fire Saturday afternoon in West Texas, the law enforcement arm of the Postal Service confirmed on Sunday.

The United States Postal Inspection Service (USPIS) announced in a statement, “The Postal Service is shocked and saddened by the events that occurred yesterday in the Midland-Odessa area. We are especially grieving the loss of our postal family member, letter carrier Mary Granados, age 29, and we continue to keep her family in our thoughts.”

The mail carrier “was carjacked and murdered while working,” according to a GoFundMe page created to help Granados’ family with funeral expenses.

“I had the privilege to work with Mary in the past,” Leslie Aide, who created the page with the permission of Granados’ twin sister, wrote. “She was beautiful inside and out, with a great heart and always ready to be a friend, always had a smile on her face!”

Investigators said Sunday the gunman, whom police did not identify, was acting alone when he killed seven people, ranging in age from 15 to 57, and injured at least 22 others, including three law enforcement officers and a 17-month-old girl, with an “AR-type weapon.”

GUNMAN IN TEXAS SHOOTING RAMPAGE ARMED WITH 'AR-TYPE WEAPON,' ACTED ALONE, INVESTIGATORS SAY

Texas Gov. Greg Abbott said the toddler who was wounded in the shooting would undergo surgery Monday to remove shrapnel from her chest. Fox 34 in Lubbock, Texas, citing a hospital spokesman, reported that the 17-month-old has been released Sunday. It is unclear if her surgery had already taken place.

Odessa Police Chief Michael Gerke suggested Sunday that more people could have died had police not killed the gunman outside a crowded movie theater. Two of the victims died overnight.

The police chief said he wasn’t naming the shooter, described by officials Saturday as a white man in his 30s, because “I refuse to.”

“I’m not going to give him any notoriety for what he did,” the chief said.

The shooting began around 3 p.m. Saturday after state troopers pulled over the gunman for making a left-handed turn without signaling.

In the chaos that followed, the suspect hijacked the mail carrier truck and fired at random, investigators said.

FRIGHTENING VIDEO: FAMILY, OTHERS APPEAR TO TAKE COVER DURING TEXAS SHOOTING

Gerke said 15 separate locations had been designated crime scenes.

The Texas Department of Public Safety spokeswoman said the driver “pointed a rifle toward the rear window of his car and fired several shots” at the troopers as he was still moving.

She said the gunshots struck one of two troopers inside the patrol car, after which the gunman took off and continued shooting.

17-MONTH-OLD GIRL SHOT IN TEXAS RAMPAGE EXPECTED TO MAKE FULL RECOVERY

Two other police officers were shot before the suspect was killed. Investigators said the trooper was in serious but stable condition on Saturday, and the other officers were stable.

Gerke said investigators had not yet established a motive for the shooting. FBI Special Agent in Charge Christopher Combs said the killer had no apparent connection to terror groups.

Investigators said the gunman had a criminal history and according to online court records, he was arrested in 2001 in McLennan County, Texas, and charged with misdemeanor criminal trespass and evading arrest. According to records, he entered guilty pleas in a deferred prosecution agreement where the charge was waived after he served two years of probation.

Investigators have not said where he got his “AR-type weapon.”

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The rampage marked the second mass shooting in Texas in a month. A gunman killed 22 people in El Paso earlier in August.

Fox News’ Maggie Kerkman, Robert Gearty and The Associated Press contributed to this report.