Vanessa Hampton, 32, of Frankford, was arrested last week in Philadelphia and is awaiting extradition to New Jersey where she is facing charges of manslaughter and possession of a controlled dangerous substance.
The investigation began in November 2022 when Medford Township police responded to a home for an unresponsive infant.
The boy was taken to the hospital and was later pronounced dead.
SEE ALSO: Action News Special Report: Emerging drug 'tranq' leading to amputations
Action News Special Report: Emerging drug 'Tranq' leading to amputations
A medical examiner ruled the child's death a homicide, saying he died from drug intoxication after being exposed to "xylazine," or tranq, allegedly at the hands of his mother.
Xylazine is widely used in veterinary medicine as a sedative, muscle relaxant, and analgesic. In the United States, it is not approved for human consumption or medical treatment.
Officials say the drug is being mixed into fentanyl and other illicit opioids.