Authorities in South Carolina say an infant girl died from a lethal dose of morphine that was in her mother's breast milk.
The mother, 37-year-old Stephanie Greene, was charged Friday with homicide by child abuse.
Investigators say Greene's 6-week-old daughter, Alexis, was found dead in her parents' bed in their Campobello home in November 2010.
Autopsy results showed high levels of morphine in the child's blood.
Authorities say the painkiller got into Greene's breast milk after she took pills and used patches containing morphine constantly since the baby's birth.
Investigators say she illegally obtained the drugs at least 38 times in less than two years.
Greene was awaiting a bond hearing. Her husband refused to speak with a reporter or give her attorney's name when reached by phone.