Crumbley, 15, is accused of fatally shooting four students and injuring seven others at Oxford High School on Nov. 30. The four deceased victims are 16-year-old Tate Myre, 14-year-old Hana St. Juliana, 17-year-old Madisyn Baldwin and17-year-old Justin Shilling.
His defense attorneys Paulette Loftin and Amy Hopp said in a court filing that their client “intends to assert the defense of insanity at the time of the alleged offense” in the filing, according to the Detroit Free Press.
Loftin did not immediately respond to an inquiry from Fox News Digital.
Crumbley pleaded not guilty earlier this month to 24 charges, including first-degree murder and terrorism, in connection with the mass shooting. His parents, James and Jennifer Crumbley, also face four counts of involuntary manslaughter each.
Oakland County prosecutor Karen McDonald revealed in December that school officials met with Crumbley and his parents to discuss violent drawings he created just hours before the deadly rampage.
The 15-year-old suspect was able to convince them during the meeting that the concerning drawings were for a “video game.” His parents “flatly refused” to take their son home.