The infant shot and killed in a suburban Lancaster apartment on Christmas Eve is Kestyn Davis, and her parents are cooperating with the investigation, police said Thursday.
The girl's parents are Alyssa and G. Scott Davis, police said.
An autopsy determined on Thursday that Kestyn died of a single gunshot wound to the abdomen. She was killed by a handgun.
Authorities said an adult relative fired the fatal shot, but they declined to identify the shooter.
Police said they expect the investigation to be completed in a few days.