A Johnson County man told police he shot his son after an altercation ensued inside his home in rural Grantsburg, according to a statement from the Illinois State Police.
The Illinois State Police and Johnson County Sheriff's Office responded to the call about 6 p.m. on Monday.
The homeowner, Henry Bullock, 75, of Grantsburg, told police that his son, Brandon Bullock, 43, also of Grantsburg, entered his home, and "an altercation ensued causing the homeowner to shoot his son," an ISP news release stated.
An autopsy for the deceased was scheduled for 10 a.m. Tuesday.
Illinois State Police's Ullin office is leading the investigation. No additional details were provided.