Maine, USA (AP) — A 10-year-old girl was charged with manslaughter in the death of an infant after detectives found "troubling signs" during the investigation today.

The girl, who is not being identified, is the youngest person to be charged with manslaughter in Maine in at least 25 years. Authorities said the infant, Brooklyn Foss-Greenaway, of Clinton in central Maine, had been under a baby sitter's care but did not say whether the suspect was the sitter.

The girl is in the custody of the Maine Department of Health and Human Services, said Stephen McCausland, spokesman for the Maine Department of Public Safety. Police declined to identify the girl, who is due in juvenile court in October. Her attorney didn't immediately return a call from The Associated Press.

The baby's parents live in Clinton and had arranged for the child to spend the night at a babysitter's home in nearby Fairfield.

Police said the sitter called police early July 8 to report that the infant was not breathing. Emergency officials who arrived six minutes after receiving the call reported the child was unresponsive and not breathing.

The death of any child under age three triggers an automatic investigation in Maine, and detectives uncovered some "troubling signs" before the state medical examiner declared the death a homicide, McCausland said.

The death was declared a homicide Wednesday, but investigators withheld further details on the cause of death.

The charge was filed after detectives consulted with the attorney general's office, which determined manslaughter was most appropriate, said Brenda Kielty, a spokeswoman. Unlike murder, which generally involves an intentional act, manslaughter charges are brought when a homicide is caused by reckless actions or criminal negligence.

The charge is extremely unusual because of the defendant's age.

The state doesn't have any data on the youngest person ever to be charged in a homicide in Maine, Kielty said. But it's been at least 25 years - and possibly longer - since someone so young has been charged with manslaughter or murder in the state, officials said.

Fairfield is about 70 miles northeast of Portland, the state's largest city.