SPRING, Texas (AP) — A registered nurse has been charged with capital murder in the shooting of a young mother and the abduction of her newborn son at a pediatric clinic near Houston, a prosecutor said Wednesday.

Montgomery County District Attorney Brett Ligon told ABC's "Good Morning America" that Verna McClain, 31, was charged early Wednesday in the killing of Kala Marie Golden.

Witnesses say an argument broke out between Golden and another woman as Golden left Northwoods Pediatric Center in Spring on Tuesday afternoon with her 3-day-old son, Keegan.

The woman repeatedly shot Golden then snatched the baby from her arms and went to drive away in a blue or light green Lexus, according to witness accounts. The dying woman leaned into the vehicle and tried to take Keegan back, screaming "My baby!" but her attacker sped away.

Ligon said McClain's statement to investigators indicates that she shot the mother as part of a wider plan to kidnap any child and that Golden was simply in the wrong place at the wrong time.

"There were statements as indicated in the arrest record that were made by Ms. McClain that led us to believe that, in fact, this was an intentional act on her part," Ligon said. "Not that Ms. Golden was targeted specifically, but that this was part of a plan to kidnap a child."

He made no mention of a man whom witnesses said they saw in the blood-splattered Lexus.

Keegan was found unharmed Tuesday evening. Ligon said Child Protective Service officials were looking after him but that they expected the baby to soon be reunited with his father.

Speaking to Houston television station KHOU on Tuesday, Keegan's father, Keith Schuchardt said he was going to miss Golden.

"She was sweet, lovable. I loved her, and she loved me," Schuchardt said. "Everything was going fine until today."

Authorities have not said where Keegan was found. Ligon stressed that the infant was not found at a nearby apartment complex that was raided by officers wielding guns and riot shields Tuesday evening. Spring is about 20 miles north of Houston.

Authorities detained a person of interest late Tuesday, but it wasn't immediately clear if that person was McClain, nor if she was detained during the raid. Jail records show McClain lived in Houston.

McLain, a nurse, is not employed by the Northwoods Pediatrics Center, according to a receptionist at the clinic, Jackie Longoria.

Golden's mother, Linda Golden, told the AP that she had been baby-sitting another of Kala's sons when someone at the scene called her using her daughter's cellphone. She rushed to the clinic but was unable to see her daughter because paramedics were trying to save her.

"I wanted to kiss her before they put her in the ambulance," Linda Golden said.

Joshua Jesson said he was at the clinic with his girlfriend when he heard gunshots. He said he saw a Lexus next to the pickup truck, then later looked back and saw the car was gone and a woman lying in the spot where the Lexus had been parked.

"I thought she just passed out. Then somebody ran in here and said, 'Somebody got shot,'" he said.

Police quickly surrounded the clinic and much of the parking lot with crime-scene tape, and yellow markers were placed next to a purse and pair of brown sandals near a red pickup truck. Spent ammunition also was nearby.

Linda Golden described her daughter as sweet-natured and kind.

"We went everywhere together and did everything together," she said.

She said she had no idea what could have sparked the slaying and abduction.

"That's the hardest she's ever fought," Linda Golden said. "She died trying to save her baby."