Updated

A newborn infant kidnapped from his mother in Tennessee was found safe in Alabama on Friday, and a woman suspected of abducting the baby was arrested, police said.

Nashville police said week-old Yair Anthony Carillo was found at a home in Ardmore near the Tennessee line.

Tennessee Bureau of Investigation Director Mark Gwyn identified the arrested woman as Tammy Renee Silas, 39, of Ardmore. He said charges are "pending," but she was not immediately charged. She was being questioned and will be held at the jail in Morgan County, Ala., police said.

The infant underwent a medical checkup in Alabama and was in good health, authorities said. They were still making arrangements early Saturday to reunite him with his mother, 30-year-old Maria Gurrolla.

"This baby is a week old, and this child has spent half his life away from his family. I think it's time we reunite them," said My Harrison, a special agent with the FBI in Tennessee.

The TBI said they would be reunited through the Tennessee Department of Children's Services.

The baby and Silas were found about 10 p.m. CDT and Silas did not resist arrest, Gwyn said. Police in Nashville did not know if Silas has a lawyer. Authorities said they had no word on a possible motive.

The infant was taken from his home Tuesday, just four days after he was born. His mother told police a heavyset white woman with blonde hair arrived at her home posing as an immigration agent, attacked her with a knife, then took the boy.

A break in the case came as a task force of local, state and federal investigators developed strong information on a car seen following the mother and baby from the parking lot of a Walmart store, police said.

Investigators on Friday had released a sketch of a suspect developed with Gurrolla's help and said it would be posted on billboards in Tennessee and other Southeastern states. TBI spokeswoman Kristin Helm said the billboard was intended to spur more tips from the public as leads in the case began to diminish.

Cathy Nahirny, a senior analyst for infant abduction cases at the National Center for Missing & Exploited Children, said there have been at least two other recent cases where an abductor used a ploy similar to the one used in this case.

"We need to get the word out to our immigrant communities," Nahirny said. "Anybody that claims they are from federal law enforcement agencies, you have the right and you should ask for photo identification."

Abductions of infants by strangers are rare, with only nine reported cases so far this year and five last year, according to the missing child center.

Nahirny said immigrant families have been targets of child abductions because of the assumption they will not tell police.

Gurrolla is Latina but her immigration status isn't clear. She was stabbed several times in the neck and chest and was released from the hospital Thursday.

Nahirny said abductors have also impersonated health care or social services workers to gain access to homes or visited health care facilities to find new mothers to target.

In 2005, the Nashville mother of a newborn and her 3-year-old daughter were killed by a woman trying to steal the baby after finding the family through a food stamp office.

Typically the abductor does not harm the infant.

"In their mind, that's their baby now," Nahirny said.

Harrison expressed relief that little Yair Anthony Carillo was found safe.

"Federal, state and local law enforcement have worked tirelessly for the last three days," she said. "It is not always that we have this outcome and we should be thankful."