ROCK HILL — Police on Monday arrested a York mother who in July gave birth to a baby girl that tested positive for cocaine in her system at a Rock Hill hospital.

Heather Ann Oliver, 23, of 2969 Chester Hwy. is charged with unlawful conduct of a child, according to Rock Hill police documents. By Tuesday evening, she was jailed at the city prison on a $25,000 bond.

On July 16 at 9:06 a.m., Oliver gave birth to a baby at Piedmont Medical Center. Doctors found traces of cocaine metabolite in the baby’s stool, indicating that “Oliver consumed cocaine during the third trimester of her pregnancy,” a police report reads.

Police in September received a referral from the York County Department of Social Services to investigate Oliver. They issued a warrant for her arrest in October, and she was entered into the National Crime Information Center as a wanted person.

She turned herself in Monday, Lt. Brad Redfearn said.