This booking photo released by the Oakland County, Mich., Sheriff's Office shows Ethan Crumbley, 15, who is charged as an adult with murder and terrorism for a shooting that killed four fellow students and injured more at Oxford High School in Oxford, Mich., authorities said Wednesday, Dec. 1, 2021. (Oakland County Sheriff's Office via AP)

A 15-year-old boy is being charged as an adult for opening fire Tuesday afternoon at Oxford High School in Oxford Township, killing four students and injuring seven others, including a teacher.

Oakland County Prosecutor Karen McDonald announced that Ethan Crumbley has been charged with one count of terrorism causing death, four counts of first-degree murder and seven counts of assault with intent to murder.

Investigators said Crumbley was armed with a semi-automatic handgun purchased last week by his father. McDonald said charges may also be issued against Crumbley’s parents.

A well wisher kneels to pray at a memorial on the sign of Oxford High School in Oxford, Mich., Wednesday, Dec. 1, 2021. A 15-year-old sophomore opened fire at the school, killing several students and wounding multiple other people, including a teacher. (AP Photo/Paul Sancya)