15-year-old accused Oxford High School shooter Ethan Crumbley, who is being charged with the murder of four students, is expected to plead insanity.

Per the Detroit Free Press, defense lawyers for the alleged school shooter said on Wednesday that he intends to pursue such a defense. “Please take notice that...Ethan Crumbley intends to assert the defense of insanity at the time of the alleged offense," said the court filings from his lawyers Paula Loftin and Amy Hopp.

The news comes the same week students returned to school, as the Free Press reported.

Crumbley previously pleaded not guilty to charges including four counts of first-degree murder, seven counts of assault with intent to murder, 12 counts of possession of a firearm, and one count of terrorism. Crumbley was arrested and charged as an adult following the shooting on Nov. 30, 2021. Four people died and seven were injured, including a teacher.

In order for the insanity defense to stand up in court, Crumbley will need to undergo psychiatric evaluation. County Prosecutor Karen McDonald, however, has suggested results of the evaluation will have no impact on whether he’ll face charges. Throughout the case, prosecutors have asserted that Crumbley showcased troubled behavior and expressed much interest in firearms and Nazi propaganda.

Parents Jennifer and James Crumbley are also facing charges in connection with the shooting. They were charged on Dec. 3 with involuntary manslaughter, and prosecutors have said they ignored multiple warning signs that their son was exhibiting dangerous behavior. Additionally, they were responsible for gifting their son with the 9mm SIG Sauer SP 2022 firearm he used in the shooting. He allegedly received it as an early Christmas gift, and the parents failed to safely store the weapon in their home.

"The (parents) had information long before Nov. 30 (six months prior to the shooting) that their son's only friend moved at the end of October, that the family dog died, that their son was sadder than usual, and that he was sending his mother disturbing texts about his state of mind," read court documents from the prosecution. "Instead of paying attention to their son and getting him help, they bought him a gun." 

Prosecutors have heavily focused on cellphone videos Crumbley recorded the day before the shooting. He asserted in the clips that he planned to kill other students at the school. “This was absolutely premeditated,” said McDonald. 

"[The parents] did not intervene. They did not schedule therapy,” added assistant prosecutor Marc Keast. “Instead, they bought him what he desperately wanted … a handgun.”

Students returned to the Oxford High School campus on Monday, just under two months after the shooting happened. “As a community, we will get through this with love and grace for one another," said superintendent Tim Throne.