Swissvale officers were called to help medics get into the apartment in the 7800 block of Sailor Place shortly before 10:15 a.m., Allegheny County police said in a statement.
"First responders found an adult female victim deceased from a gunshot wound and a female child deceased from a gunshot wound. Preliminary investigation shows this was a double homicide," county police said in the statement.
The victims have not yet been identified.
County homicide detectives are investigating. Anyone with information is asked to call 833-ALL-TIPS.
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