FOX LAKE, IL - SEPTEMBER 01:  An Illinois State Police officer stands guard outside Grant High School as parents arrive to pick up their children while nearby, police continued to search for suspects involved in the shooting death of a police officer September 1, 2015 in Fox Lake, Illinois. The school, only blocks from the search area, remained on lockdown for most of the day. Police are searching for three suspects who killed the officer from the Fox Lake Police Department this morning.  (Photo by Scott Olson/Getty Images)