Police say the shooter may be one of several males spotted running from the rear parking lot of Dorchester High School and then getting into a late-model brown Cadillac that drove on Edson Street toward Norfolk Street. The city's ShotSpotter system detected the sound of gunfire about that time on Edson Street, police say, adding that several vehicles and homes suffered bullet damage during the onslaught.
The girl was taken to Boston Medical Center for treatment and is expected to recover.
"I am outraged by the cowardice demonstrated by the violent individuals responsible for this senseless act, Police Commissioner Ed Davis said. "Their total disregard for human life resulted in a tragic injury to a child."
People with information can contact detectives at (617) 343-4712 or call the anonymous tips line at 1-800-494-TIPS (or by texting TIP to 27463.