Two teachers at Oxford High School in Oakland County, Mich., reported concerns over
Ethan Crumbley's behavior in the days before the 15-year-old went on a shooting spree, killing four of his classmates and leaving seven others injured, according to the county sheriff.
School authorities also met with his parents the morning of the shooting.
Concerns over Crumbley's behavior were first reported on Monday after "a teacher in the classroom where he was a student saw and heard something that she felt was concerning," Oakland County Sheriff Michael Bouchard
said on CNN's "New Day."
Crumbley underwent a counseling session with school officials, and a phone call was made to his parents after the report.
Two hours after the second meeting, Crumbley left the bathroom with a loaded handgun and started shooting, the sheriff said on Tuesday.
Bouchard said the teenager did not leave the school after the meeting, but had remained on campus and possibly kept the gun in his backpack or tucked in his waistband.