Ethan Crumbley, 15 at the time, killed four classmates and injured seven in the November 2021 shooting, leading to James Crumbley facing four counts of involuntary manslaughter.
Jennifer Crumbley, James's wife, was found guilty of the same charges weeks before, marking a rare instance of parents being criminally responsible for their child's shooting.
School officials warned the Crumbleys about concerning drawings and expressed concerns about Ethan's well-being on the day of the shooting, offering immediate mental health care options, which the parents allegedly ignored.
Counselor Shawn Hopkins and dean Nicolas Ejak testified that James Crumbley appeared appropriately concerned during the school meeting preceding the shooting.
Prosecutors argued that both parents could have taken action, as Jennifer admitted she could have left work and brought her son with her, while James, a DoorDash driver, had flexible hours.
James Crumbley made a 911 call after discovering the missing gun, identifying his son as the suspected shooter before police made that information public.
Judge Cheryl Matthews limited James Crumbley's prison communications due to alleged threats, allowing only research and communication related to his defense until the jury reaches a verdict.