Baltimore police say a mixture of methadone and baby formula killed a 5-month-old girl and led to first-degree murder charges against the child's mother: Teresa Ann Younger, 25, of the 4600 block of Freedom Way in Northeast Baltimore.
The infant, Matia Grant, died the morning of March 4 at Bon Secours Hospital.
The baby was not breathing when Younger took her to the hospital for treatment.
Younger, arrested Friday, is accused of lacing the baby's formula with methadone the night of March 3 because the child was restless, homicide detectives said.
Younger is being held at the Baltimore City Detention Center. Bail was denied.
An autopsy on Matia revealed high levels of methadone in the child's blood and liver.
In large doses, methadone -- an addictive syrup given to addicts as a less-dangerous substitute for heroin -- can cause the respiratory system to fail.
The case was ruled a homicide based on the autopsy report and a toxicology test done on a half-full bottle of formula taken from the child's home the day she died.
During a summer-long investigation, detectives discovered that Younger was in a methadone program.
Charging documents against Younger note that she had a take-home prescription for methadone.
The suspect, who is the mother of two other children, entered drug treatment last year while pregnant with Matia.
Clarence Williams, director of a drug treatment program at Bon Secours, said methadone is an odorless liquid that does not cause euphoria but can satisfy heroin cravings for 24 hours.