ISP – An investigation is underway following a deadly shooting in Johnson County Monday night. According to a release from the Illinois State Police, officers were called to a home in rural Grantsburg at around 6:00pm for a death investigation. When they arrived the owner of the home, 75-year-old Henry Bullock told officers that his son, 43-year-old Brandon Bullock had entered his home and during an ensuing altercation, Henry shot and killed his son. An autopsy is scheduled for this morning. No further information will be released at this time.