PRINCE WILLIAM COUNTY, Va. (WRIC) — The Prince William County Police Department has announced that a woman whose 20-month-old child was found to have taken a lethal dose of fentanyl is in custody.

According to police, 37-year-old Tiffany Nicole Stokes turned herself in and was arrested on Tuesday, Dec. 13.

Stokes was charged with felony child neglect, felony homicide and possession of a schedule I or schedule II narcotic. This comes a week after police issued warrants for her arrest in connection to the death of her 20-month-old child.

Just after 3 a.m. on July 23, Prince William County Police officers responded to a home on the 14700 block of Soapstone Drive in the Gainesville area for a report of an unconscious 20-month-old child. The child was taken to a local hospital, where he died.

At the time of the child’s death, police did not suspect anything suspicious or unusual had occurred. However, about a month later, the Office of the Medical Examiner determined that the child had a lethal amount of fentanyl in his blood, which caused his death.

Investigators interviewed Stokes again and said it was determined that at the time of the child’s death, she had access to a pill containing oxycodone and acetaminophen, as well as pills that are believed to have contained Percocet, neither of which had been prescribed.