UPDATED at 2:05 p.m. with update on timeline of police investigation.

ELLISVILLE • The blue towel under the pine tree was moving strangely.

It caught Betty Crowder's eye from the kitchen window of her daughter's house as she prepared breakfast Thursday morning.

She looked again. It was still moving, so she stepped outside and walked toward the tree that is just outside her own nearby home.

"I heard this little groaning, whimpering sound," said Crowder, 78.

Someone must have dumped a litter of puppies, she thought. She didn't lift the towel but went inside and scanned telephone listings for animal control or the Humane Society.

No one was answering in the early morning. She got recordings saying offices were closed.

After finally reaching someone by phone, she was transferred to Ellisville police. An officer was dispatched about 7:45 a.m. to check out the bundle.

Officer Chuck Kraus, 26, of south St. Louis County, said he slowly lifted the dirty, bloody towel with his nightstick. That's when he heard a cry and a cough, and knew there were no puppies beneath the towel.

He and Crowder were stunned by what they saw.

"We said, 'Oh my God, it's a baby,'" Crowder said.

The umbilical cord was still attached. Kraus and another officer who came to the scene wrapped the baby in dry towels and put him to a police car until paramedics arrived. Kraus said it was perhaps the most unusual call he has had since joining the department last March.

"They always say, 'expect the unexpected,' but I didn't show up there thinking I'd find a kid," Kraus said.

The infant found in temperatures that had dipped into the low 40s was cold, but he appeared to have no injuries and is expected to be OK, said Ellisville Police Chief Tom Felgate. An ambulance took him to Mercy Hospital in Creve Coeur for treatment.

Late Thursday afternoon, police said the mystery of who dumped the child was solved.

Ellisville police Sgt. Nancy Walker said the infant's 19-year-old mother, of west St. Louis County, had checked into a St. Louis-area hospital about 3 p.m. for treatment.

Hospital staff contacted police, and detectives went to the hospital — not the same one where her baby was being treated — to interview the woman, Walker said. The woman was in good condition and cooperated with police.

Kraus said he has heard talk around the police station that hospital staff have nicknamed the boy "Baby Chuck" after him.

Police say the mother is expeted to come to the Ellisville police station next week after she is released from the hospital. After that happens, detectives plan to present the case to St. Louis County prosecutors for potential charges. 

Parents of babies younger than 1 have immunity from felony child abandonment and child endangerment charges under Missouri's Safe Place for Newborns law if they leave their child with an emergency medical professional or with an on-duty employee at any hospital, fire department or law enforcement agency.

The law is intended to protect newborns and infants from injury and death caused by abandonment by providing a safe and secure alternative for the parent. The law does not release the parent or guardian from possible criminal charges if the baby was harmed prior to relinquishing the child.

The pine tree where the baby was found Thursday is about 10 feet off the back corner of the house where Crowder has lived since 2000. The tree is at the edge of a pine tree-lined water retention basin.

Crowder said she had no clue why her yard was picked as a place to discard the baby.

"It's mind-boggling to me," she said.

Felgate said whoever abandoned the baby probably will face criminal charges.

The police chief said the newborn is lucky Crowder saw him and called for help. "I think this lady saved the baby's life," he said.

Crowder said she didn't feel heroic but was just being persistent about helping what she thought were some helpless animals.

"You see something, and you do what's necessary," she said. "At least the baby is in good hands. They'll probably find him a good home."

Nancy Cambria of the Post-Dispatch contributed to this report.