Jennifer Crumbley said that she didn’t know her son was armed and blamed Oxford High School officials for not checking his backpack on November 30, the day the shooting took place.

Her trial continued Wednesday before Oakland County Circuit Court Judge Cheryl Matthews.

Last year, Ethan Crumbley was sentenced to life in prison with no chance of parole for murdering four fellow students and shooting and injuring seven others.

Oxford High School Dean of Students Nicholas Ejak on Tuesday told the court that school officials had no reason to suspect Ethan Crumbley was a potential threat that required them to search his backpack, the Detroit Free Press reported.

Ejak also testified that he met with Ethan Crumbley and his parents in the school counselor’s office the morning of the shooting to discuss a drawing made by Ethan Crumbley on a math assignment sheet. The drawing depicted a gun and a bleeding body, and the message: “Blood everywhere … My life is useless … The thoughts won’t stop. Help me.”

Instead of taking him home and scheduling an appointment with a counselor, Ethan’s parents returned to their jobs, Ejak said.

The court on Wednesday heard testimony from Brian Meloche, a man who admitted he was having an affair with Jennifer Crumbley and discussed Facebook messages she exchanged with him after the shooting.

The messages indicated she was upset following the shootings and agonized over the school being “nonchalant” about the matter and not checking his backpack that day, The Detroit News reported.

Jennifer Crumbley faces up to 15 years in prison on four counts of involuntary manslaughter for giving her son access to the semi-automatic handgun that he used in the shooting.