Pittsburgh Bureau of Police officers from Zone 2 were called to perform a welfare check on a resident in an apartment building on the 2100 block of Centre Avenue Friday morning.
Officers found the resident, a 72-year-old male, deceased on the floor inside his apartment.
Homicide detectives arrived and took over the investigation.
It initially appeared that the victim died of natural causes, but after further on-site investigation, it was determined that the victim had sustained a gunshot wound or wounds to the upper body.
The investigation is ongoing.