The Camden County Prosecutor's released the test results Monday showing 34-year-old Chevonne Thomas had used the drug before killing her son and putting his head in a freezer.
The woman had suffered from mental illness and had twice lost custody of her son because of drug use. It was believed from the Aug. 22 tragedy that she was using the drug known as "wet," which is linked to violence in some users.
The same drug was linked to another horrific crime in Camden weeks later. In that case, authorities say a man broke into a home where he attacked a sleeping girl, then fatally stabbed her 6-year-old brother.