Donna Muller and her son Richard Muller were identified as the victims found shot to death in their Philadelphia home.
Muller, 49, and her son lived in the Lawncrest section of the city.
The gunshots were heard overnight.
Officials say a 29-year-old neighbor found the victims on Sunday.
It’s definitely a violent crime scene because you have two dead bodies that appear to be shot in the head,” Chief Inspector Scott Small told ABC.
Neighbors said they heard two pops and other noises around 3:30 a.m.
“I don’t know what to say. It’s a shame,” neighbor John Downey told NBC. “They are nice people. They don’t deserve it.”
“At this time we don’t think neighbors should be concerned for their safety, we do not believe that,” said Chief Inspector Small.