Police said a grandfather shot his daughter and six children before killing himself in a house in Bell, Florida.
Gilchrist County Sheriff Robert Schultz said that babies are between three months and 10 years old.
Authorities identified the gunman as Don Charles Spirit, 51.
Schultz said a colleague responded to reports of gunfire and upon arrival contacted Spirit before killing himself.
After Spirit committed suicide, the police found the other seven bodies in the house, although there were other people still alive.
According to the Florida Department of Corrections, the grandfather was behind bars for the shooting, and was released last February
Bell is a city of about 350 people located 30 miles west of Gainesville.