The Upper Darby teenager who allegedly abandoned her newborn baby on a stranger’s porch earlier this week told police that she was frightened and alone when she delivered the infant.

“She delivered the baby late Monday, early Tuesday in the bathroom of her house,” said Upper Darby Police Chief Michael Chitwood. “She lived with her father.”

The healthy newborn girl was found by a local resident at about 12:30 p.m. Tuesday outside the house on the 100 block of Englewood Road in Upper Darby where she was left.

“She was scared. She didn’t know what to do,” Chitwood said the 15-year-old girl told investigators. “She was alone. She cut the cord. She cleaned the baby up, wrapped the baby in a blanket, and left it on the porch.”

In an interview Saturday, the chief shared some details about how the young mother was identified and found. Two detectives were assigned full time to the case, he said.

“They scoured the neighborhood,” said Chitwood. “They knocked on doors, interviewed people, and eventually they focused on the 15-year-old girl. We learned that she was pregnant.”

The girl and father were brought in to speak with investigators, who later reached out to the teenager’s mother, Chitwood said, adding that the girl’s parents reside separately.

The chief said the teenager’s mother “was very, very instrumental” in getting the girl to tell the police her account of what happened.

Police announced Friday that the baby’s mother had been located. Chitwood said charges were still pending against the juvenile, but since the girl had no prior criminal charges, she was allowed to go home.

The baby, meanwhile, is in foster care. Since news spread about the abandonment, at least 50 people have contacted police, inquiring about adopting her, Chitwood said.

The fate of the infant and her young mother will likely rest in the hands of child welfare and Family County authorities.