Oak Forest police said officers responded to the 15000-block of block of Sunset Avenue for an unresponsive person around 6:20 p.m. Friday.
Michael Arnold, a 68-year-old Oak Forest man, was pronounced dead on the scene, police said.
The Cook County Medical Examiner's Office said Arnold suffered from multiple gunshot wounds and ruled his death a homicide.
The Oak Forest Police Department Investigations Unit and the South Suburban Major Crimes Unit are investigating the death.
Police asked anyone with information to contact their investigator at 708-687-1376.