Fifteen-year-old Ethan Crumbley opened fire inside Oxford High School in Michigan on Tuesday, shooting eleven individuals.
Three students were killed in the shooting. They have been identified as Tate Myre, Madisyn Baldwin, and Hana St. Juliana. Another student, Justin Shilling, succumbed to his injuries on Wednesday, and several others have been hospitalized.
Crumbley, has been hit with murder, terrorism, assault and weapons possession charges. Authorities claim the shooting was premeditated, so he has been charged as an adult.
But what was Crumbley's motive?