Fifteen-year-old Ethan Crumbley opened fire inside Oxford High School in Michigan on Tuesday, shooting eleven other students.
Seventeen-year-old Madisyn Baldwin, 16-year-old Tate Myre, and 14-year-old Hana St. Juliana were killed in the shooting. A fourth student, 17-year-old Justin Shilling, died of his wounds on Wednesday.
Crumbley has been charged as an adult with multiple crimes. His parents, James and Jennifer Crumbley, now also face charges.
Oakland County Prosecutor Karen McDonald revealed disturbing details about the case in a press conference on Friday -- and they concern Crumbley's parents.