Authorities say they believe a 50-year-old man killed his parents and himself after learning they intended to remove him from their suburban Chicago home where he also lived.

Winfield police released an update on the investigation Tuesday. The bodies of 77-year-old Nancy Clinkenbeard, 76-year-old Clyde Clinkenbeard and their son, Karl Clinkenbeard, were discovered May 21 after a concerned citizen spotted unconscious people through a window and called 911.

Police say the attack likely took place on May 20 following an argument a day earlier involving another family member that was reported to police. The DuPage County coroner's office says the Clinkenbeards each suffered "multiple sharp force injuries."

Officers who forced their way into the home found two bodies together and the third in a different room.