Verna McClain told her fiance she had given birth to their child. But after she suffered a miscarriage, authorities said, she went looking for another baby to present to him.
Now she's accused of killing a young mother to take one by force.
Investigators say McClain waited outside a pediatrician's office north of Houston and shot Kala Golden before taking her tiny newborn son, who was only 3 days old.
Little Keegan Golden was found unharmed hours later with McClain's sister -- who was told that her sister planned to adopt the boy. He is back with family members.
McClain is charged with capital murder and was being held Wednesday without bond. Authorities say she admitted attacking the woman Tuesday and stealing her baby from his mother's pickup truck.
McClain, 30, who listed a Houston address, was separated from her husband, with whom she had raised three children.
"I don't understand that, her taking a child," her estranged husband, Theo McClain, of San Diego, told The Associated Press. "That doesn't make sense. We have three kids. And then to shoot somebody? I've never known her to hurt anybody."
McClain had told her fiancé she had given birth to their child. Instead, McClain had miscarried, said Capt. Bruce Zenor of the Montgomery County sheriff's office.
Her fiancé, who was not identified Wednesday, is being interviewed by authorities.
Sheriff Tommy Gage said 28-year-old Kala Golden had placed Keegan into her pickup truck Tuesday afternoon after leaving Northwoods Pediatric Center in Spring, about 20 miles north of Houston. The suspected shooter was parked next to her, Gage said.
The woman repeatedly shot Golden, then snatched the child from her truck and drove away, according to witness accounts. The dying woman leaned into the vehicle and tried to take the boy back, screaming, "My baby!" but her attacker sped off.
Later Tuesday, two detectives spotted a vehicle outside a nearby apartment complex that matched witnesses' descriptions, Gage said. Though McClain's apartment was empty, she showed up and talked to authorities.
During an interview, detectives learned of a residence in Harris County where McClain's sister lives and the child might be, Gage said.
McClain's sister, Corina Jackson, told authorities that she had talked about needing to "do the adoption" soon after taking Keegan.
McClain was later arrested. Police say she admitted carrying out the attack. They do not believe anyone else was involved.
Investigators said McClain's statements included information only the shooter would know and indicated Tuesday's attack was part of a wider plan to kidnap any child. Golden was simply a convenient target, authorities said.
McClain's children are with a family member in the county, authorities said.
The kidnapped baby has been returned to his family, according to his father, Keith Schuchardt, who said he had been married to Kala Golden for three years.
He told the Houston Chronicle that he learned of the shooting because as Golden lay dying, she asked another woman to call him and explain the attack.
Asked by reporters what he would tell his wife now, Schuchardt said, "I wish you were here with me to get me through this."
Schuchardt, who also has a 2-year-old and a 4-year-old, said officials were initially concerned about his criminal record, which includes felony convictions for possession of a controlled substance and burglary of a coin-operated machine.
Gwen Carter, a spokeswoman for Texas' Department of Family and Protective Services, said Schuchardt could see his children as often as he wanted while authorities worked on the case.
McClain is a vocational nurse at a local staffing agency, a job that involves providing basic nursing services under the direction of registered nurses and doctors. She does not work at the pediatric center, according to a clinic receptionist, Jackie Longoria.
McClain, who has vocational nursing licenses in both California and Texas, has not faced disciplinary action in either state, according to licensing boards.
Golden's mother, Linda Golden, told the AP that she had been baby-sitting 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.
Linda Golden said she had no idea what could have sparked the slaying and abduction.
"That's the hardest she's ever fought," she said. "She died trying to save her baby."
Associated Press writers Ramit Plushnick-Masti in Spring and Nomaan Merchant and Danny Robbins in Dallas contributed to this report.