An autopsy shows 74-year-old Norman England of Freelandville, Indiana died from a gunshot wound.
His body was found last week in a home on State Highway 1 near Flat Rock, Illinois in Crawford County.
Illinois State Police and the Crawford County Sheriff's Department say they're pursuing all leads in the investigation.
On Thursday, police announced that they arrested Matthew Miller for burglarizing the same home where England's body was found.
Police have not specifically linked the two cases together.